The Bucket Foundry

[WilDun]

Guess if I were to build one (ie sander), it would need a decent motor to drive it? (ie more than a normal small bench grinder) I'm sure that it would be used for all sorts, not only draught, draft?? angles on patterns,( the British Vs American way of spelling things is "daft") maybe we should invent a Kiwi way of saying it!.:laugh:

Although I have dabbled with CAD and do actually use DesignCad 3D a little I haven't as yet gone into the 3D "solid stuff" - would be great to get into CadCam like Rhino etc. but really I think I've left it all a little too late and there's not much point in me wasting my time and money in that stuff (wish all this had been around in 1960). so will just stick to learning the basic foundry stuff,which is quite fulfilling.

Neil, you reckoned that the best way of turning pine would be to glue it together with the grain positioned the right way, do you mean (for example when turning a round piece), it should be running in a radial direction from the centre to the OD as near as possible?

[Flettner]

Guess if I were to build one (ie sander), it would need a decent motor to drive it? (ie more than a normal small bench grinder) I'm sure that it would be used for all sorts, not only draught, draft?? angles on patterns,( the British Vs American way of spelling things is "daft") maybe we should invent a Kiwi way of saying it!.:laugh:

Although I have dabbled with CAD and do actually use DesignCad 3D a little I haven't as yet gone into the 3D "solid stuff" - would be great to get into CadCam like Rhino etc. but really I think I've left it all a little too late and there's not much point in me wasting my time and money in that stuff (wish all this had been around in 1960). so will just stick to learning the basic foundry stuff,which is quite fulfilling.

Neil, you reckoned that the best way of turning pine would be to glue it together with the grain positioned the right way, do you mean (for example when turning a round piece), it should be running in a radial direction from the centre to the OD as near as possible?

The motor doesn't have to be too big as the disc (steel usually) has a lot of inertia, mine is three phase with an old micro drive (found in some rubbish a business was throwing out) so I can change the speed depending on what I want. Sand paper disc lasts for over a year and is held on with velcro with one half being glued to the steel disc originally. Well worth the time to build one.
I'll see if I have a picture of glueing/turning pine rings on the lathe somewhere?

[WilDun]

The motor doesn't have to be too big as the disc (steel usually) has a lot of inertia, mine is three phase with an old micro drive (found in some rubbish a business was throwing out) so I can change the speed depending on what I want. Sand paper disc lasts for over a year and is held on with velcro with one half being glued to the steel disc originally. Well worth the time to build one.
I'll see if I have a picture of glueing/turning pine rings on the lathe somewhere?

That would be good to have a look at, I've just been having a go with the timber I found earlier after having glued it together yesterday, it has a fairly coarse grain, turned nicely, but I don't think it could be used without bog to fill in the coarse ends of the grain.

BTW, Please don't get stuck in the mud and try to pull your foot out in the normal way, they say a dislocated hip joint can be an extremely painful thing and a trip in an ambulance all the way from the track is something else! - the YZ might just outlast you!. (I really don't mean to be a killjoy, even if I am, but ....... I have been through the bloody mill myself!).

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/IMG_4959_zps32845be7.jpg

http://i1056.photobucket.com/albums/t380/uniflow/IMG_4960_zpsa3c22856.jpg

http://i1056.photobucket.com/albums/t380/uniflow/IMG_4961_zps4bb82079.jpg


Horrizontal split case reed.

See the wood segments been glued end to end to make the upper crank case, with a bit of amorboard inserted.
Old furniture is usually very dry and stable and generally free.

[WilDun]

See the wood segments been glued end to end to make the upper crank case, with a bit of amorboard inserted.
Old furniture is usually very dry and stable and generally free.

Thanks, I now see that so long as the end of the grain isn't exposed, it'll be ok for turning either across the grain or along it. - learning all the time! and I'm sure that free timber offcuts are just about the easiest to find, being everywhere.

I don't think I would have got this far with a foundry if it wasn't for the fact that I had to "save face" after putting myself on the line and telling you all what I was "gunna" do! - sure helped to keep me honest with myself, ie. about what I can and can't do! :yes:

[Ocean1]

The motor doesn't have to be too big as the disc (steel usually) has a lot of inertia, mine is three phase with an old micro drive (found in some rubbish a business was throwing out) so I can change the speed depending on what I want. Sand paper disc lasts for over a year and is held on with velcro with one half being glued to the steel disc originally. Well worth the time to build one.
I'll see if I have a picture of glueing/turning pine rings on the lathe somewhere?

A mate copied mine, but he used 6mm steel plate for the disk, was too thin, it rings like a bell and causes weird finishes. So it needs to be thick enough to be stable. Doing mine again I'd see if I could find a bit of heavy cast iron, in fact now that I think about it a small car flywheel might be a good place to start, make the drive flange big enough to fill the recess in the centre.

If single phase is all you've got and you want a decent diameter then you might have to flick it over by hand before hitting the switch...

I use mine for stainless steel a fair bit, and the heat from that kills anything but silicone carbide, so I buy rolls and cut my own disks and use bear disk cement to glue them straight to the steel. If I wasn't sanding SS I'd be buying the sticky back disks off the shelf.

[Flettner]

A mate copied mine, but he used 6mm steel plate for the disk, was too thin, it rings like a bell and causes weird finishes. So it needs to be thick enough to be stable. Doing mine again I'd see if I could find a bit of heavy cast iron, in fact now that I think about it a small car flywheel might be a good place to start, make the drive flange big enough to fill the recess in the centre.

If single phase is all you've got and you want a decent diameter then you might have to flick it over by hand before hitting the switch...

I use mine for stainless steel a fair bit, and the heat from that kills anything but silicone carbide, so I buy rolls and cut my own disks and use bear disk cement to glue them straight to the steel. If I wasn't sanding SS I'd be buying the sticky back disks off the shelf.

I think mine is 20mm steel, 600mm dia. Micro drive starts up well but takes a little time. I ballanced it with a pistol drill and it's been good but lately it's had a bit of a shake on at certain RPM so I had a look for the problem. All my ballance holes had filled up with sawdust, a good blow out and it's fine again. To be fair I haven't used it much lately, it's turned into just another bit of bench space:yes:

[Ocean1]

I think mine is 20mm steel, 600mm dia. Micro drive starts up well but takes a little time. I ballanced it with a pistol drill and it's been good but lately it's had a bit of a shake on at certain RPM so I had a look for the problem. All my ballance holes had filled up with sawdust, a good blow out and it's fine again. To be fair I haven't used it much lately, it's turned into just another bit of bench space:yes:

Could kill two birds with one Microdrive VFD, use a 3ph motor with a decent shaft size, (>25mm?) and drive it with a 1ph>3ph VFD.

[WilDun]

now that I think about it a small car flywheel might be a good place to start, make the drive flange big enough to fill the recess in the centre.
If single phase is all you've got and you want a decent diameter then you might have to flick it over by hand before hitting the switch...


Sounds good, I know a source for big cast iron brake discs and car and truck flywheels all sitting out in the weather waiting to be made into sanding discs for a couple of bucks each!
I see single phase motors can be had for reasonable prices if you search around for them - I think 3 phase are much cheaper and easier to get (but unfortunately they're not for me).
Guess it would be possible to rig up a belt drive with a few pulleys which could serve as a clutch as well as a speed changer to give a little motor a chance to get the disc wound up.
Maybe I'm letting my imagination run away with me here, ie as far as equipment is concerned - my wife's little car already has to stay outside!!

[Flettner]

Sounds good, I know a source for big cast iron brake discs and car and truck flywheels all sitting out in the weather waiting to be made into sanding discs for a couple of bucks each!
I see single phase motors can be had for reasonable prices if you search around for them - I think 3 phase are much cheaper and easier to get (but unfortunately they're not for me).
Guess it would be possible to rig up a belt drive with a few pulleys which could serve as a clutch as well as a speed changer to give a little motor a chance to get the disc wound up.
Maybe I'm letting my imagination run away with me here, ie as far as equipment is concerned - my wife's little car already has to stay outside!!

Probably already told this story, when Claire and I were first married we had a small car shed. The rules were that the car had to go in the shed each night, made work a little difficult some nights and at 10.00 PM it was lights out! There was a lead out to the shed from the wash house and Claire would just switch the power off, no matter what, even if I was half way through a cut on the Boxford lathe as happend one night, broke the cutting tip, wreaked the job. Apparently it was my fault for not being better at reading the time!
In my opinion cars should stay outside when important work is going on in the car shed anyway.

[Yow Ling]

Guess if I were to build one (ie sander), it would need a decent motor to drive it? (ie more than a normal small bench grinder) I'm sure that it would be used for all sorts, not only draught, draft?? angles on patterns,( the British Vs American way of spelling things is "daft") maybe we should invent a Kiwi way of saying it!.:laugh:

Although I have dabbled with CAD and do actually use DesignCad 3D a little I haven't as yet gone into the 3D "solid stuff" - would be great to get into CadCam like Rhino etc. but really I think I've left it all a little too late and there's not much point in me wasting my time and money in that stuff (wish all this had been around in 1960). so will just stick to learning the basic foundry stuff,which is quite fulfilling.

Neil, you reckoned that the best way of turning pine would be to glue it together with the grain positioned the right way, do you mean (for example when turning a round piece), it should be running in a radial direction from the centre to the OD as near as possible?

You could just make a disk that you could chuck in your lathe, would work ok

[WilDun]

You could just make a disk that you could chuck in your lathe, would work ok

Trouble is, I've only got a Boxford (like Neil used to have), 9'' swing, and a belt that will slip at the slightest provocation, ( I bet you'll remember that Neil) - that means trouble every time you try to sand a decent amount off! - also extremely dangerous for me, my blood pressure will go right off the scale with the frustration hence the likleyhood of a stroke! :laugh:
Might be better to start from scratch and build one, or even convert my bench grinder!

[WilDun]

Could kill two birds with one Microdrive VFD, use a 3ph motor with a decent shaft size, (>25mm?) and drive it with a 1ph>3ph VFD.

A decent usable VFD doesn't just fall out of the blue (well, sometimes they might fall into a skip) ;)
but even with my Goldcard, there wouldn't be much chance of finding a cheap enough one for me! (although having said that, I did manage to score a good 40:1 Penfold box for $2 at the tip).

[GerbilGronk]

The sander of Neils is a real beast. It has a huge amount of inertia which is great for sanding but it takes about 15 minutes to stop spinning when it gets turned off. As it winds up the earth slows down slightly. ;) You wouldn't want to get tangled up in it.

[WilDun]

The sander of Neils is a real beast. You wouldn't want to get tangled up in it.

No, I'm going to play things safe from now on, I've got tangled up in too much machinery (including bikes) over the years! So I might design some sort of belt sander which could also be used for doing the draught angles on patterns, but today I'll be making a proper lid for my furnace (hopefully).

[seattle smitty]

. . . and Claire would just switch the power off, no matter what, even if I was half way through a cut on the Boxford lathe as happend one night, broke the cutting tip . . . .

Bet the tool had a carbide tip. It's typical of carbide that if the lathe spindle is allowed to coast down, the very last thing that happens before it stops is the tip of the carbide tool breaks off. You quickly learn not to leave the tool in the cut when you stop turning.

That's about the second thing I learned when I went from HHS tooling to carbide many decades ago, the first being that carbide let me make gigantic cuts that could generate huge smoking blue coils winding out of the cut!!

[Ocean1]

Bet the tool had a carbide tip. It's typical of carbide that if the lathe spindle is allowed to coast down, the very last thing that happens before it stops is the tip of the carbide tool breaks off. You quickly learn not to leave the tool in the cut when you stop turning.

That's about the second thing I learned when I went from HHS tooling to carbide many decades ago, the first being that carbide let me make gigantic cuts that could generate huge smoking blue coils winding out of the cut!!

My old boss would have kicked my arse for that. He'd have insisted that the feed and cut be set so the chip breaker worked.

[Flettner]

Bet the tool had a carbide tip. It's typical of carbide that if the lathe spindle is allowed to coast down, the very last thing that happens before it stops is the tip of the carbide tool breaks off. You quickly learn not to leave the tool in the cut when you stop turning.

That's about the second thing I learned when I went from HHS tooling to carbide many decades ago, the first being that carbide let me make gigantic cuts that could generate huge smoking blue coils winding out of the cut!!

Yes, High Speed Steel, I call it low speed steel. It's only used for "special" jobs now(special shapes etc).

[WilDun]

Yes, High Speed Steel, I call it low speed steel. It's only used for "special" jobs now(special shapes etc).

I find that "Low Speed Steel" is a very good thing for rescuing and getting a smooth finish on a final cut which might not be going well with carbide. By using a slow rotational speed, small feed and plenty of cutting oil. it produces a dull but smooth finish. - HSS can't be written off!

[WilDun]

My old boss would have kicked my arse for that. He'd have insisted that the feed and cut be set so the chip breaker worked.

Yes, however that's hard to keep constant as each cut will be different, but big blue coils coming off are a real menace and so are blue chips if they go down your shirt, or hit your face! :eek:

[Grumph]

There was a guy here in ChCh who was a very good engineer - and a well known special builder and driver - Hec Green. Long dead now.
However one of his parlour tricks was to grind a HSS tip to shape and machine hardened steel with it.
This trick became known in trade circles, to the point that a visiting Japanese trade mission actually turned up at his factory with a new HSS toolpiece and a piece of hardened steel shafting, demanding to see it done.
He made them stay in the office where they could see him but not see detail, went out and ground the tip, machined the piece as requested, then ground the shape right off the toolpiece and gave it all back to the japs...proved it could be done.
Not even his business partner - another very good engineer - ever knew what the shape was. Hec was a very secretive old B....

[Ocean1]

Yes big blue coils coming off are a real menace, but so are blue chips if they go down your shirt, or hit your face! :eek:

I've had one adhere to my tongue, in the split second it took for me to lick my lip. Couldn't get the bastard thing off.

I once did a job on a big planer, about an 8ft stroke. Was finishing a cut on a stainless steel table insert with a carbide, easyflowed tip, had a curved face about 10thou deeper in the middle than the sides and about 30deg top rake. Feed was something like 1/2", it was making 8ft x 1/2" razor blades, you could just about see through the edges.

Didn't have much choice about the swarf, the tool did a good job but it piled up beside the machine. I told the old cleaner, (who was at least a sammie short of a picnic) to leave it alone until I went to get a fork or something. I came back to find him sitting on the floor with most of the front of his hand missing. I felt like shit for ages.

[WilDun]

He made them stay in the office where they could see him but not see detail, went out and ground the tip, machined the piece as requested, then ground the shape right off the toolpiece and gave it all back to the japs...proved it could be done.

Sounds like a challenge for someone! - amazing the stuff we lose forever through people being secretive, but then look what happens when we share it all - some other b*****d cashes in on it!

I heard somewhere that a Russian delegation went to England a while after WW2 to check out the RR Jet engines. RR had supplied details and drawings to them earlier to see if they were interested in trade but didn't disclose the materials being used.
The Russians had brought their own "safety" boots to use in the workshop, stood round the machines doing the turbines etc and walked over the chips then packed the boots back in their suitcases and went home complete with all the chips collected by the special sticky soles they had on the boots.
They analysed the chips and found out what materials to use and proceeded to copy the engine which was then fitted to the very successful MIG 15! - that's how the story goes anyway.

OCEAN, as I said, that swarf is a menace, but you can't tell some people (many people!) - some people also will insist on looking at arc welders!

[F5 Dave]

Nice story, they were given complete engine though as part of a political deal, in secret to get them on side with the Brits in some misguided move. All this stuff was released a while back & subject of a few telly programs. Apparently the 'mercans were somewhat surprised at the sudden development hike the Ruskies had achieved.

[WilDun]

All this stuff was released a while back Apparently the 'mercans were somewhat surprised at the sudden development hike the Ruskies had achieved.

Yeah, I heard it secondhand and I thought that there might be another angle to it, - I didn't see the documentaries. Even so, it's hard to believe some of the things which take place at diplomatic level, (ours is not to wonder why.........etc.)
Also, we were quite brainwashed too, we were told that Russian aircraft were inferior to anything in the west (not so) and that Russian and Ukranian etc. women were ugly looking cows who looked and worked like men!! (also not so).

[F5 Dave]

Meanwhile they were told Stalin was a top bloke and onions were an acceptable diet.

[WilDun]

Meanwhile they were told Stalin was a top bloke and onions were an acceptable diet.

Well he was a top bloke, he scored more points than Hitler in the people killing stakes, and what the hell is wrong with onions?

[seattle smitty]

The smoking blue coils were just for fun, the first time I found out how big a cut I could take. Chip-breakers after that. But I still use HSS a lot, out of long habit I guess, and knowing how I want them ground.

MikeT1, is there another forum where you have photos of your Pietenpol? (For others, who were intrigued by the idea of an airplane powered by a Ford Model A engine, the same designer offered an even simpler, cheaper, single-seat version (this was during the Depression) to be powered by a Model T engine!!!).

[WilDun]

But I still use HSS a lot, out of long habit I guess, and knowing how I want them ground.
cheaper, single-seat version (this was during the Depression) to be powered by a Model T engine!!!).

HSS is definitely much more versatile and much cheaper for the home workshop.

Hadn't heard of the Pietenpol with a Model T engine!

Another 'story' (which I think I mentioned before somewhere - getting old and starting to repeat myself!).
When Pietenpol built his plane with a Model A up front, the experts of the day had said it couldn't be done. Asked by reporters afterwards what he thought of that, he replied that if only he had known it was impossible, he would never have attempted it. :facepalm:

[MikeT1]

Hi Smitty, I haven't really posted much in the way of what I'am doing with the Pietenpol, would prefer to get it closer to being a functioning reality, it has taken much longer than I anticipated, age is slowing me down a little, grandchildren living with us take a lot of my time. The wing requires assembly, the rest of the aircraft is near complete, needs wiring and power plant installation, I will test fly the airframe with a subaru engine, which is what I used in a previous aircraft. The boiler and water tanks are completed, the engine is in the late design stage, need to finish working drawings, then make patterns for casting the major components.
The single seat 30 hp Model T powered sky scout was never as popular as the two seat 40 hp Model A powered aircamper, later the aircamper was fitted with the 100 hp Chev corvair flat six and performed even better.

[Frits Overmars]

When Pietenpol built his plane with a Model A up front, the experts of the day had said it couldn't be done. Asked by reporters afterwards what he thought of that, he replied that if only he had known it was impossible, he would never have attempted it. It's the story of the bumblebee all over again.
It has been scientifically proven that a bumblebee can't fly (body mass versus wing area and all that), but nobody told the bumblebee :p.
313558

[WilDun]

Mike,
No doubt we'll see the Pietenpol flying around Papakura or Pukekohe - we'll probably hear the Subaru coming but not sure what sort of noise the steamer will make, maybe we'll hear the prop or the wind whistling around the struts! - I do understand about looking after the grandchildren.
Can't be a lot of Corvair engines left, they are all in aircraft!
Frits,
You do wonder how a bumblebee does fly, but it does and that's the only explanation I need!
It's great to see the doubters being silenced sometimes, even those who say that there can't be free energy.
Some things may take more than a lifetime to work out but so what, a lot of fun was had trying! (a lifetime of being cynical can't bring a lot of joy!).

[seattle smitty]

Surely some of the Pietenpol builders who use a Model A engine have one of the later variants (Model B and C, IIRC) with full pressure oiling, and there are lots of aluminum heads for that engine, plus you could save more weight by building your own manifolds from tubing. Upgraded in this way, that plane might climb out with some energy, especially if pilot and payload stay Depression-era-skinny.

But a Pietenpol steamer!! That will really boil along!! Very cool, I mean hot, project

[Grumph]

Surely some of the Pietenpol builders who use a Model A engine have one of the later variants (Model B and C, IIRC) with full pressure oiling, and there are lots of aluminum heads for that engine, plus you could save more weight by building your own manifolds from tubing. Upgraded in this way, that plane might climb out with some energy, especially if pilot and payload stay Depression-era-skinny.

But a Pietenpol steamer!! That will really boil along!! Very cool, I mean hot, project

There are several aftermarket full pressure oiling conversions available for the Model A. Most of the owners of restored A's i've met at Vintage car gatherings have done it just to keep up with modern traffic.

[Flettner]

I'm a little worried about the drive sahft size:msn-wink:

Shortened Bedford Truck shaft.

[Grumph]

By comparison, the engine mounts look a tad flimsy...

Reminds me of a speedway car a family friend had. Kept breaking driveshafts or joints till they asked the old man to have a look...
His first question was "who told you to put the joint yokes at 90 degrees to each other ?"

[ken seeber]

Neil,
I'm not gunna say the shaft will shit itself (cos it's way strong), but I reckon that a big juicy flywheel on the engine would be a good thing for the benefit of the engine, the splined shaft, U/Js and the dyno. A single would be much worse, but even a twin can strain things.
From what I saw, the best couplings were 6 hole rubber discs, 3 equispaced holes for an input flange and the other 3 equispaced holes for the output flange, the shafts being centred with s spigotted spherical bearing. Mercedes use these, 100 years ago. I think, these were a standard fitment with the Schenck eddy current dynos we used.

[husaberg]

I'm a little worried about the drive sahft size:msn-wink:

Shortened Bedford Truck shaft.

Neil as always your output is amazing (see what I did there:whistle:)
Being from where you are though I thought you would have gone more agricultural theme.
I am not going to tell my father you have Bedford bits either.
313578
slip clutch used on slashers
313576
One way clutch used on Non live drive such as Fergies
313577
Pto shaft

[Frits Overmars]

From what I saw, the best couplings were 6 hole rubber discs, 3 equispaced holes for an input flange and the other 3 equispaced holes for the output flange, the shafts being centred with a spigotted spherical bearing. Amen to that.

[Flettner]

Taken care of.

[Grumph]

Tell me about those Urethane inserts - have you got a mould/cutting die for that shape ?

They look just what is wanted for the family of Kawasaki clutches used on 600/650/750 fours....The OE rubbers always collapse.

[Flettner]

Tell me about those Urethane inserts - have you got a mould/cutting die for that shape ?

They look just what is wanted for the family of Kawasaki clutches used on 600/650/750 fours....The OE rubbers always collapse.

I made a die, as you would expect. I'll post diameters for you on Monday, I'm off on forced weekend off/holiday, wife said!

[MikeT1]

How well do the bushes stand up to warm oil?

[Grumph]

How well do the bushes stand up to warm oil?

I've used Urethane in situations where they were "wet" with no probs.

frankly, I'm being lazy, hoping to get what i want off Neil rather than doing a die of my own.
If they're suitable, I have 2 customer kawasaki's they'd go in, plus Yow Ling has another...

[Yow Ling]

I've used Urethane in situations where they were "wet" with no probs.

frankly, I'm being lazy, hoping to get what i want off Neil rather than doing a die of my own.
If they're suitable, I have 2 customer kawasaki's they'd go in, plus Yow Ling has another...

Yes I think I do !

[WilDun]

i had a good weekend and I finally managed to do my first casting which was a very good feeling. It wouldn't have made the grade (in a commercial sense) but I considered it a success even though there were a few issues with shrinkage, leaving some cavities in the middle, this I can no doubt rectify in the future.
i machined it and bored out the middle to see how big the cavities were (enough to spoil it if was to be used) but I'm nevertheless flushed with success! (It's roughly about the size of my fist).
The wooden finned pattern is just something I used to practice my pattern making (soft pine, very fragile) = not much good!
To be honest, the moulding and casting isn't really as big a deal as I thought it would be, even though this time I stuffed up the moulding by using greensand which was slightly too dry! but now that I've got started I intend to continue to improve until its right.

What is it? - well it's a .......um......phuctifino! :scratch:

[ken seeber]

Willy,
Congratulations yung fella, nothing like the first splash.:done:
Not sure of its overall dimensions, but the central shrinkage was probably inevitable without a core or a chunkier riser.

[WilDun]

Willy,
Congratulations yung fella, nothing like the first splash.:done:
Not sure of its overall dimensions, but the central shrinkage was probably inevitable without a core or a chunkier riser.

Thanks Ken,
I did have the feeling the risers might be a little slender but it was such a nice day, nothing was going to stop me (not even a stuffed up moulding) - I thought, what the hell, let's just suck it and see and think about it later! - can't waste a good day like this, they're a bit few and far between here at the moment.

The ally I'm using is probably high silicon ( a couple of small diesel pistons and a couple of injector pump bodies) a bit poor for machining but ok for this purpose.

[husaberg]

Thanks Ken,
I did have the feeling the risers might be a little slender but it was such a nice day, nothing was going to stop me (not even a stuffed up moulding) - I thought, what the hell, let's just suck it and see and think about it later! - can't waste a good day like this, they're a bit few and far between here at the moment.

The ally I'm using is probably high silicon ( a couple of small diesel pistons and a couple of injector pump bodies) a bit poor for machining but ok for this purpose.

What actually is it Will?

[WilDun]

What actually is it Will?

Like I said Husa, "phuctifino"

Actually if I had to say what it is,I would call it a "solid doodle" :laugh:

[husaberg]

Like I said Husa, "phuctifino"

Actually if I had to say what it is,I would call it a "solid doodle" :laugh:

You oldies and your Viagra..........

[WilDun]

You oldies and your Viagra..........

If I had to use Viagra I'd probably either have a heart attack and keel over - or die of shame! ;)

[ken seeber]

If I had to use Viagra I'd probably either have a heart attack and keel over - or die of shame! ;)

Willy, don't lie! We're a pair of mature, virile and "upstanding" citizens. :niceone: Don't let that young whippersnapper Hoosa distort the truth.

[Flettner]

Might be a few sermon's screeched from this pulpit, hopefully.

Rubber cush drives at 28.8mm Dia by 20mm wide. 8mm slot inside.

Hussa, can you find what I'm using the rest of the Bedford drive shaft for?

[ken seeber]

More "upstanding"

[Flettner]

i had a good weekend and I finally managed to do my first casting which was a very good feeling. It wouldn't have made the grade (in a commercial sense) but I considered it a success even though there were a few issues with shrinkage, leaving some cavities in the middle, this I can no doubt rectify in the future.
i machined it and bored out the middle to see how big the cavities were (enough to spoil it if was to be used) but I'm nevertheless flushed with success! (It's roughly about the size of my fist).
The wooden finned pattern is just something I used to practice my pattern making (soft pine, very fragile) = not much good!
To be honest, the moulding and casting isn't really as big a deal as I thought it would be, even though this time I stuffed up the moulding by using greensand which was slightly too dry! but now that I've got started I intend to continue to improve until its right.

What is it? - well it's a .......um......phuctifino! :scratch:

Good to see, yes a nice big riser (feeder) out of the most solid part of the casting would be good, don't worry about the little riser you are using. The "in" port is the runner and usually is necked off (thin) where it enters the cavity. it's to help stop turbulance and to minimise the shrinkage (pull) from the casting as the runner sets. Hey, who am I to say, just some observations.

Good on you for actually doing it is what I ment.

[Grumph]

Rubber cush drives at 28.8mm Dia by 20mm wide. 8mm slot inside.

Too small OD, I need around 32mm OD, slot is right though which is why i asked. Thanks, and bugger.

Will, I've built two bikes for a southern customer, he calls one Viagra, and the other Cialis....

[WilDun]

The "in" port is the runner and usually is necked off (thin) where it enters the cavity. it's to help stop turbulance and to minimise the shrinkage (pull) from the casting as the runner sets. Hey, who am I to say, just some observations.

I thought I'd never manage to get to do that and now that I have, I'm keener than ever - "keener" I said, not "faster"!

I had noticed a neck in a lot of feeders and wondered what their function was, now I know. Thought maybe it was to make them easier to cut off!
BTW, I depend on all the tips I get from all you guys who actually do castings and everybody else as well -these tips are worth a lot more to me than reams and reams of technical data! - that's not to say that the data isn't important of course, but I haven't got the time to wade through all that stuff anymore. :facepalm:

[Flettner]

Too small OD, I need around 32mm OD, slot is right though which is why i asked. Thanks, and bugger.

Will, I've built two bikes for a southern customer, he calls one Viagra, and the other Cialis....

You could always press in little steel sleeves to bring the size down to 28.8 ?

[WilDun]

Will, I've built two bikes for a southern customer, he calls one Viagra, and the other Cialis....

Well, guess that's original! - natural stimulants - much safer too! :yes:

[Grumph]

You could always press in little steel sleeves to bring the size down to 28.8 ?

That's how I've been making the OE rubbers last a bit longer...Do you cut from 20mm sheet ? Ideally. i need 10mm thickness too.


Well, guess that's original! - natural stimulants - much safer too! :yes:

The first time i rode the Z1 racebike he calls viagra, it nearly killed me. Certainly raised the blood pressure - and adrenaline levels.
For those who want details, bumpy country road, wheelspin....back off ? hell no.

[WilDun]

The first time i rode the Z1 racebike he calls viagra, it nearly killed me. Certainly raised the blood pressure - and adrenaline levels.

Viagra's definitely not for me then - in any shape or form! :laugh:

[MikeT1]

Good to see Wil, I wish you more sucess than me, I have found at least a dozen ways of not getting a usable part when casting, the few sucesses keep me trying. Making a pattern for a Sopwith throttle quadrant at present, it is very thin section, to be cast in brass, should be interesting.

[WilDun]

Mike T,
As I said sometime earlier, every failure is a lesson learnt - and as I also said, my attempt would have been a failure from a commercial point of view!

I don't remember much about steam engines, but I was interested in them many years ago and have a couple of old books which I had recently dug up. They are on Stuart stationary engines and are complete with plans, they look like they might be fun to build, ie using home made castings.
Do you know what material those castings were, there is no indication on any of the drawings of materials used, but I guess they expected you would be using their castings - could they be done using aluminium?

Also I remember that later developments in steam engines and being discussed in books stated that, 'uniflow' type engines were becoming popular - is that that type of engine you are using?

[Ocean1]

I don't remember much about steam engines, but I was interested in them many years ago and have a couple of old books which I had recently dug up. They are on Stuart stationary engines and are complete with plans, they look like they might be fun to build, ie using home made castings.
Do you know what material those castings were, there is no indication on any of the drawings of materials used, but I guess they expected you would be using their castings - could they be done using aluminium?

http://www.stuartmodels.com/item/43/stuart-beam-unmachined

[WilDun]

Thanks - looks like cast iron (as I suspected), I however, I'm not that advanced with my casting! - still think it could be done in ally, after all the temperatures won't involve superheated steam and IC engines use aluminium - guess I could give it a try.
I would prefer trying some other original stuff rather than just follow drawings though.

[MikeT1]

Yes Wil, the stuarts were cast iron, however I built a brass slide valve engine for a friends model boat, it ran well. I think corosion and wear would be a problem if using aluminium. You should be able to melt brass in your furnace.

[Ocean1]

Yes Wil, the stuarts were cast iron, however I built a brass slide valve engine for a friends model boat, it ran well. I think corosion and wear would be a problem if using aluminium. You should be able to melt brass in your furnace.

Aye, that Stuart casting schedule included CI, alloy and brass. You might struggle to manage CI with your rig but brass should be perfectly do-able. Alloy and steam just don't mix, be OK for frames and chassis but that's about it.

[WilDun]

My furnace might manage brass ok, even bronze, but that would probably be a struggle! - don't think it could take the heat required for iron.
Brass was (from experience) good for smooth finishes etc. but those little needles produced by machining it were a pain! still, it looks as good as bronze and a lot cheaper!

[Flettner]

Got the dyno to load today, first time it;s run in ????? years. Works well, with a ball valve to load and unload it's water circuit, external heat exchangers run form a 1000 L tank. Saw 100 psi on the torque piston so will now need to calibrate it. Lots of black water and froth came out but the water circuit has cleaned up now. It seems very easy and accurite to load, bearings are fine, smooth and quiet.

[Grumph]

Got the dyno to load today, first time it;s run in ????? years. Works well, with a ball valve to load and unload it's water circuit, external heat exchangers run form a 1000 L tank. Saw 100 psi on the torque piston so will now need to calibrate it. Lots of black water and froth came out but the water circuit has cleaned up now. It seems very easy and accurite to load, bearings are fine, smooth and quiet.

Now if you could operate the water valve by servo and link that in to a tacho function you'd have a quick way of getting load readings at stepped RPM....

But i've been spoilt using a Dynopak setup which does that for you. Very nice too.

[Flettner]

Now if you could operate the water valve by servo and link that in to a tacho function you'd have a quick way of getting load readings at stepped RPM....

But i've been spoilt using a Dynopak setup which does that for you. Very nice too.

Yes, on the mark two setup, for now I just have to get results. G clamps and zippy ties everywhere. Exhausts held in place with ladders and a plank (and springs).

[Frits Overmars]

Got the dyno to load today, first time it;s run in ????? years.... It seems very easy and accurite to load...My first brake was not unlike yours; it was a British Heenan & Froude water brake. But it was never designed to cope with racing two-strokes. When the engine came on the pipe, the revs immediately shot sky-high because once in the power band the engine's torque curve was way steeper than the brake's torque curve.
Doubling the brake's rpm and tripling the water pressure finally reshaped its torque curve into something more or less usable. But the high water pressure made the hoses want to straighten which influenced the force actuated by the brake on the scales. Besides, controlling the water flow was by a hand wheel and laying a hand on it already influenced the scales. If you want to measure anything like accurately, you'll need a fast servo control on the water flow.

[Flettner]

MikeT1 , how many are you? I read in the motor times about a guy in the Waikato who makes steam bikes? Tell me there is not two of you?

[MikeT1]

Hi Flettner, don't think it was me in the paper. So there must be more than one steam bike nut out there. How is the dyno working out ? been waiting for an update. Have modified mine to gear up the drive to the alternator and increase the load on the engine, need to recalibrate the rpm and load cells to suit.

[Flettner]

Hi Flettner, don't think it was me in the paper. So there must be more than one steam bike nut out there. How is the dyno working out ? been waiting for an update. Have modified mine to gear up the drive to the alternator and increase the load on the engine, need to recalibrate the rpm and load cells to suit.

The out door nature of my dyno is not so good in winter, waiting for a few fine days.

[Michael Moore]

Yesterday my friend Jeff had a foundry party at his house. Some photos from it are in this folder on my website:

http://www.eurospares.com/graphics/metalwork/foundry/

Jeff and I have been collaborating on accumulating foundry supplies for casting aluminum. Jeff has made a high-performance propane furnace while I've picked up a nice electric kiln. But until yesterday we hadn't tried melting/pouring any metal.

Jeff organizes a dirt bike ride in the California Sierras each year, and one of his friends on the ride designed and had 3D printed a medallion to give to everyone. The printed part was used as the pattern. I think this was a laser/resin print, definitely not a filament deposition job (and Chris said the model cost about $160 to have done, and that was with a hollow back to reduce the amount of time and material needed to print). The medallion surface and detail looks very nice. The raised sections are .75mm tall. That design in the middle is the route for the ride. Before molding the pattern was filled with Bondo to eliminate flex.

Since there was only one pattern and about 20 copies were needed we knocked together a number of small flasks. We poured 3 or 4 times.

Since no great mechanical properties were needed (and we didn't know if things would work) the material was scrap - lots of pistons, aluminum connecting rods, small chunks from the machinery scrap bucket. We have ingots of A365 alloy for when we try casting some actual motorcycle parts.

We tried both commercial green sand and Petrobond and decided that we preferred the Petrobond.

You can see in Medallion3.jpg that some of the medallions are not so nice in the middle. We think that was due to the sprue coming straight into the pattern and slightly damaging the mold. But we didn't make the flasks large enough to offset the sprue and use a gate so we were kind of stuck.

I had bought a hot suit, spats and foundry gloves, but the process was much less dramatic than expected (I guess I'd been looking at photos of steel foundries with sparks belching out of blast furnaces) so they didn't get used. But I think I'll wear them anyway when I try melting with my electric furnace just in case Mr. Murphy pays a visit.

All in all everyone was pretty chuffed with how things came out. Everyone got to try their hand at making a mold. Jeff did the lifting/pouring and I skimmed dross for him. Even the "less good" medallions will clean up well enough so that everyone gets a souvenir made from motorcycle parts.

cheers,
Michael

[TZ350]

That's Great ... grate party and interesting thing to do.

[WilDun]

Yesterday my friend Jeff had a foundry party at his house.
I had bought a hot suit, spats and foundry gloves, but the process was much less dramatic than expected But I think I'll wear them anyway.
cheers,
Michael

Sounds like a great time was had by all!

I have also found that it's not such a big deal and the dire warnings may put a lot of people off doing it.

No need to go overboard with safety gear,(talking aluminium here) but it's a good idea to always be prepared for the worst case scenario.
I think commonsense and having everything on hand, is probably the most important part of the safety requirements!

[MikeT1]

It pays to be carefull, as two of my friends and myself can testify, thankfully I was wearing a face shield and the others were standing back enough to not recieve too much splatter. I had finished the pour and was pouring the excess into ingot molds which appeared dry - there was an almighty bang and molten ally everywhere, my faceshield carries the scars to this day thankfully not my face.

[WilDun]

It pays to be carefull, there was an almighty bang and molten ally everywhere,

I think Flettner had a very similar experience a few years ago - he can explain.

I had a bad enough experience with wax recently (which can also cause severe burns) and I also had skin grafts on my right leg from a mishap with meths many years ago.

However, (as I see it), going overboard with safety gear can sometimes hamper movement etc. and doesn't overcome bad planning of your layout and not knowing where everything you need is located before the operation.
Yes I firmly do believe in a face shield of some sort - even a welding helmet! and leather gloves and boots. Maybe cotton overalls are ok. - no synthetics! and as you have just pointed out no dampness where the melt is being poured.

[Flettner]

I think Flettner had a very similar experience a few years ago - he can explain.

I had a bad enough experience with wax recently (which can also cause severe burns) and I also had skin grafts on my right leg from a mishap with meths many years ago.

However, (as I see it), going overboard with safety gear can sometimes hamper movement etc. and doesn't overcome bad planning of your layout and not knowing where everything you need is located before the operation.
Yes I firmly do believe in a face shield of some sort - even a welding helmet! and leather gloves and boots. Maybe cotton overalls are ok. - no synthetics! and as you have just pointed out no dampness where the melt is being poured.

Yes, face mask, leather jacket, gloves and special casting shorts:laugh:
Yes we did have an "incident" a few yeas ago, dumb and dumber.

[WilDun]

Yes special casting shorts:laugh:

:killingme

I've found fireproof black singlets to be less restricting and cooler in the summer than leather jackets! - leather gumboots?

[Michael Moore]

I've got a welding jacket that is made of treated cloth. It seems to work fine resisting sparks or the occasional "pop" of molten metal when welding, but I don't know how it would hold up against a significant splash.

I'm ATGATT (all the gear all the time) when I ride, so since I've got the foundry gear on hand I've no problems with making use of it.

After watching the videos on YouTube "foundry shorts" has become a standard comic term. :)

We're talking about getting together next Sunday to see how effective my electric kiln is, and maybe try some more medallions with the sprues moved off to the side.

cheers,
Michael

[Lightbulb]

Casting is one of those things, that if your method is not correct, no amount of safety gear is going to save you. I remember seeing a guy using HF acid, I said do you need gloves, he replied, if you need gloves, you are splashing the acid about. If your procedures make it so you can't splash the acid, then you don't need the gloves.
I remember casting parts for my steam engine at high school, you would not get away with how I did it then, but I made sure the cast box was heated, and made sure the tray for the left over was heated and dry. Never had any incidents what so ever, I was in summer school uniform, I did have however the full face visor on. When doing the pour, one end was attached to the wall, and I only needed to pick up and rotate in an arc to the box and the left over tray.
Neil

[WilDun]

This was cutting edge foundry gear back in the sixties, (modelled here by Trev Tosser ) - note the fireproof black singlet, the casting shorts, gumboots (leather?) and the protective hat - unfortunately back in those days gloves and face shields were not mandatory! (they were for Sheilas).
Why leather gumboots? well rubber tends to smoke a lot and attracts attention!

314623

[WilDun]

. I remember seeing a guy using HF acid, I said do you need gloves, he replied, if you need gloves, you are splashing the acid about.
Neil

I also worked with a guy who, when he first started and didn't understand our do's and dont's, went to the sink in the workshop( the same sink where we cleaned up the welds on S/S with hydrofluroric acid) and he saw the jar of clear gel and assumed it was hand cleaner.
He came and said to me "geez mate, that's pretty strong hand cleaner you've got" but he did wash his hands with it and luckily for him it's very soluble in water and he had rinsed it off reasonably quickly! It didn't really give off any warning like burning of the skin, but did give off some fumes.
I'm reliably told it can penetrate to the bones without hurting the tissue.
Seems it didn't do him any harm, but definitely not recommended for hand washing!

[Lightbulb]

The real lesson for me was to really think about what I was doing, and develop a method that makes the process as safe as possible. HF is weird stuff.
They put some on an old pair of jeans, let it sit there for a while, then washed them. After repeated washes, the material kept on rotting a bigger and bigger area every month. Just incredible to see. A lot depends on the initial concentration of the HF.
Some processes are just inherently dangerous and even the most cautious can get caught out by basic things like the weather changing and rising humidity leaving a layer of moisture on the surface. We always mixed fuel when the humidity was the lowest for the day, usually around 12-2 pm.
We avoided where possible mixing fuel on rainy days.
Neil

[WilDun]

Some processes are just inherently dangerous and even the most cautious can get caught out by basic things
Neil

Yes, as you say we can get caught out by basic things, but nearly always in the heat (no pun intended) of the moment, either through being unfamiliar with the process at the time, or at the other end of the scale, being "blinkered" by familiarity and the "that won't happen to me" attitude, (guess I'm basically talking about myself here!)
:laugh:
Flettner said "dumb and dumber" but I don't think it's got anything to do with being dumb, - more to do with being enthusiastic really!

[Frits Overmars]

Flettner said "dumb and dumber" but I don't think it's got anything to do with being dumb, - more to do with being enthusiastic really!I think Flettner was right. How else would you describe failing to keep yourself in one piece?

[WilDun]

I think Flettner was right. How else would you describe failing to keep yourself in one piece?

It's just lack of care or practical knowledge and is usually called 'ignorance' which is easily cured, but lack of brains (often mistakenly called 'dumb') can't be cured. - Of course there is sometimes the odd case where both are present That's the one to worry about. - Then would a "dummy" be into motorcycles or metal casting? - of course not! ...... well possibly not. ;)

[WilDun]

Flettner,
I'm working with wood and glue at the moment trying to make small patterns,(after a long spell of dramas with grandkids etc.)

I think I've found a good turning wood - don't really know what it is and I don't have much, but it turns very well anyway!
Because the things I am casting will be quite small, I've decided to try the Sodium Silicate/Co2 method for both pattern and coremaking - I can't afford to have any slight collapses of the mould and my reasoning is that it looks like it holds together well.

I have also been going over that stuff on page 15 of this thread where you talk about making coreboxes using casting resin for the corebox and am interested in the bit about trimming back the resin to produce a half mould, then casting the resin over the (replaced) vinamold pattern.
What I really need to know about the process is, do you take it down with a flycutter or mill - ie is the resin easy to machine without it chipping?
What sort of wax do you use between the halves before pouring the top half - is it sprayed or brushed on?

Any tips here welcome as this is all new territory for me!

[ken seeber]

Willy,

My experiences are limited with resin against resin, but the few small coreboxes we have done, mainly with fibreglass, 3D printed ABS and 2 part polyurethane, we have used various release agents: silicone spray, Mr Sheen, fibreglass style release agents and they also seem to work. I'm sure Fletto can offer much more useful info though.
As for CO2, we did some initial trials ages ago using a disposable SodaStream canister. Good for piddly sized things without the hassle of bottle rental etc. Another source we also thought of was CO2 fire extinguishers. Over here, with all our "do gooder" health and safety public servants, there are rulings on these, such that they must be serviced (??) etc or replaced at time intervals. Replacement is cheaper than servicing, meaning there are perfectly good extinguishers going to waste. The inspector guy told me that we had to dispose, or certainly not use, the replaced ones (even though they show full pressure). So, I have them in a corner with a sign on them "In case of fire, do not use"....just watch the place burn down instead.

[husaberg]

Neil wil be along soon to give you the good oil
But he uses Graphite powder in this.

<iframe width="560" height="315" src="https://www.youtube.com/embed/vKsJ2DU_3ZE" frameborder="0" allowfullscreen></iframe>

[WilDun]

Willy,

My experiences are limited with resin against resin, but the few small coreboxes we have done, mainly with fibreglass, 3D printed ABS and 2 part polyurethane, we have used various release agents: silicone spray, Mr Sheen, fibreglass style release agents and they also seem to work.
As for CO2, we did some initial trials ages ago using a disposable SodaStream canister. Good for piddly sized things Another source we also thought of was CO2 fire extinguishers.

Just having another quick look on the way to bed (fell asleep on my chair after watching the Moto GP at Brno) :rolleyes:
Most of the stuff I'll be doing is 'piddly' size and I have a Soda Stream with an exchange cylinder raring to go! When I visit the scrapyard there is usually a skip full of 'expired' Co2 bottles, maybe good material for casting - I dunno.
Never thought I would keep up the enthusiasm like I have done - five years ago I thought I was stuffed, or at least more or less incapacitated for life, but you just never know!). I do have to keep pushing myself every now and then. Making this all public also makes me keep trying in order to save face! - and ......look at all the people you meet on the way!

Husa,
That video I think was done in the commercial foundry he used previously, and everything being done there is huge compared to the stuff I'm hoping to do, so there will be a few subtle differences.
I think Neil uses graphite between the main moulding flasks now, but I'm talking about making resin coreboxes for tiny cores - graphite might do of course, but I'm pretty sure he uses spray on or brush on wax for that purpose. - we'll see....

[husaberg]

Just having another quick look on the way to bed (fell asleep on my chair after watching the Moto GP at Brno) :rolleyes:
Most of the stuff I'll be doing is 'piddly' size and I have a Soda Stream with an exchange cylinder raring to go! When I visit the scrapyard there is usually a skip full of 'expired' Co2 bottles, maybe good material for casting - I dunno.
Never thought I would keep up the enthusiasm like I have done - five years ago I thought I was stuffed, or at least more or less incapacitated for life, but you just never know!). I do have to keep pushing myself every now and then. Making this all public also makes me keep trying in order to save face! - and ......look at all the people you meet on the way!

Husa,
That video I think was done in the commercial foundry he used previously, and everything being done there is huge compared to the stuff I'm hoping to do, so there will be a few subtle differences.
I think Neil uses graphite between the main moulding flasks now, but I'm talking about making resin coreboxes for tiny cores - graphite might do of course, but I'm pretty sure he uses spray on or brush on wax for that purpose. - we'll see....

I'm Confused. your post specifies CO2 Sodium Silicate?

[WilDun]

I'm Confused. your post specifies CO2 Sodium Silicate?

My intention is to use sodium silicate in my moulding sand hardened with Co2, and also to use the same material for the cores. The main pattern can be made of wood of course, but the core (in my case) really needs to be moulded in a corebox. The corebox can be made by pouring a casting resin around an internal cavity shape. This shape is formed by pouring Vinamold into the cavity of an original example of the cavity you hope to reproduce, the copy then becomes a positive of the cavity shape, made of Vinamold - in effect a rubbery plug which can be relatively easily removed.

This Vinamold positive is then suspended by a suitable wire or long screw (which has been cast into the vinamold) in a suitable container and casting resin is then poured around it, which hardens. The Vinamold plug is then removed leaving a block of resin with a copy of the desired cavity in it.

In order to use it to make (rigid) sand cores, it now must be capable of being split into two halves so this rigid core can be removed.
To achieve this (as I understand it) Neil cuts (flycuts? mills? carves? - that's what I'm looking to find out) half of the resin corebox down to a parting line at exactly the widest part of the cavity.

The Vinamold plug is replaced in the cavity of the remaining part of the resin block, which is then set back in the container again and the top of the resin is coated with some sort of wax (sprayed on? brushed on?) and then filled up with resin again. When that has hardened, a two piece corebox is the resutl - this can then be used to produce any number rigid sand cores.

BTW. That is the process as I see it, - Neil, can you please correct me here and there where necessary? - maybe you could also tell me about the machining of the resin and the type of wax to use. - thanks.

Hopefully I've got it sussed - I'm going to try it very soon! :rolleyes:

[husaberg]

My intention is to use sodium silicate in my moulding sand hardened with Co2, and also to use the same material for the cores. The main pattern can be made of wood of course, but the core (in my case) really needs to be moulded in a corebox. The corebox can be made by pouring a casting resin around an internal cavity shape. This shape is formed by pouring Vinamold into the cavity of an original example of the cavity you hope to reproduce, the copy then becomes a positive of the cavity shape, made of Vinamold - in effect a rubbery plug which can be relatively easily removed.

This Vinamold positive is then suspended by a suitable wire or long screw (which has been cast into the vinamold) in a suitable container and casting resin is then poured around it, which hardens. The Vinamold plug is then removed leaving a block of resin with a copy of the desired cavity in it.

In order to use it to make (rigid) sand cores, it now must be capable of being split into two halves so this rigid core can be removed.
To achieve this (as I understand it) Neil cuts (flycuts? mills? carves? - that's what I'm looking to find out) half of the resin corebox down to a parting line at exactly the widest part of the cavity.

The Vinamold plug is replaced in the cavity of the remaining part of the resin block, which is then set back in the container again and the top of the resin is coated with some sort of wax (sprayed on? brushed on?) and then filled up with resin again. When that has hardened, a two piece corebox is the resutl - this can then be used to produce any number rigid sand cores.

BTW. That is the process as I see it, - Neil, can you please correct me here and there where necessary? - maybe you could also tell me about the machining of the resin and the type of wax to use. - thanks.

Hopefully I've got it sussed - I'm going to try it very soon! :rolleyes:


First page.

The bag of sand ( in the picture ) is the shell moulding sand I talk about. It is suppiled with a resin coating, this bonds to itself at approx 180 degrees C. You will need a metal die for this ( and the wifes oven ). Some of my dies are made using the CNC but some are made by copying the wood / bondifill moulds into aluminium at the foundry, then turning them into dies. This works well although they do need a little cleaning up so the sand core will slide out easily. I have a few pictures, I'll round them up if you like.
The other stuff in the pictures is the casting resin, for pattern making. It is good because it doesn't shrink or expand as it sets. It uses two equal parts. It is expensive at $380 for what you see here, adding micro ballons makes it go a little further. I have tried other products but at the end of the day this stuff is worth the money!
Good on you for having a go, I posted these pictures of making a cylinder ( pattern making ) so others might have a go instead of trying to hack out old cylinders to make them what they never were ment to be. Having the ability to cast intricate parts ( cylinders ) changes the way you will approch projects.
You will need a temp probe, I made one useing a cheap meter I bought using I think type K wire. Put it inside a stainless steel tube with the bare wire sticking out the end. There is quite a bit to melting alloy properly as you will need degassing pills and a flux of some sort.
After we had the " incident " with our home foundry I decided it was better to be friends with a local foundry and let him melt the alloy for me, I just make the moulds and put them on the floor next to his moulds.
The white sand you see is CO2 hardening sand ( cold process ), just pack it in then apply CO2 gas and will harden up instantly. This sand is not as strong as the shell hot sand process but it's good for less inticate parts. I'm not sure what is mixed with the sand, Husaburg will know.



Then after pouring a mould I cut and changed the shape to the curve I wanted
Click on the arrow after Fletner
Note you will not need to make the aluminium die if you are gong to use CO2 sand but you might run into problems with the gas not being able to escape so do plenty of vents.

[WilDun]

First page.



Note you will not need to make the aluminium die if you are gong to use CO2 sand


Husa.
I did (at one stage of my employment) make cast iron coreboxes to be used for the resin coated "shellsand/coresand". These were for the Masport Foundry (ie used for the fluid valve castings, which they made for us) and that's when I got really interested in the foundry process.

However, I won't be using this core sand because:-
(1) it stinks,
(2) it smokes,
(3) it requires metal patterns and coreboxes,
(4) it's not really suited to a small home workshop in a residential area, as is my situation.

Don't get me wrong though, it's a very good process and is used by just about every good foundry anywhere in the world, it's just not for the 'piddly' stuff that I and others like me will be making !

Thanks for all the research you do, I'm afraid I'm a bit slack about going back through long threads, - there is (in my opinion) something to be said for starting new threads when the direction of the thread changes to another subject entirely (and it often does), but I don't think everyone would agree!
That would sure help though, eg. for those who are intent on learning stuff, as opposed to light discussion, (which I also enjoy BTW).
Guess it's hard to separate the two though........:rolleyes:

[Flettner]

I'm building a new cylinder (sick of all the old half made ones)so here goes, glueing bits of armorboard together to make a male shape of the bore and ports. Finished bore will be 50mm so I've made this round center section 47mm, allowance for machining. I've cut sections out where I want to glue in male port shapes. What I'm building here will be used to make a multi piece female copy that will finish up being the sand core box ,to make sand cores and also used to make the inside part of the cylinder mould. What I'm build here will only be used once when it's done it's job it will go in the bin, the female copy of this will be used ongoing.

[husaberg]

I'm building a new cylinder (sick of all the old half made ones)so here goes, glueing bits of armorboard together to make a male shape of the bore and ports. Finished bore will be 50mm so I've made this round center section 47mm, allowance for machining. I've cut sections out where I want to glue in male port shapes. What I'm building here will be used to make a multi piece female copy that will finish up being the sand core box ,to make sand cores and also used to make the inside part of the cylinder mould. What I'm build here will only be used once when it's done it's job it will go in the bin, the female copy of this will be used ongoing.

That brings on a question re the surface to be machine finished how much is generally needed to be added for the dimensions to allow for the rough outer 3mm plus shrinkage %?

[ken seeber]

[QUOTE=Flettner;1130894119What I'm build here will only be used once when it's done it's job it will go in the bin, the female copy of this will be used ongoing.[/QUOTE]

Fletto, you're a legend in getting things done. Is there something in the water over there or the bubbly hot mud?

The only thing I can suggest is that instead of just throwing that master in the bin, chuck it in the fire. Use it twice. Nice and dry, it'll burn beautifully. Remember, FTE !! :devil2:

[Yow Ling]

Hey Flettner , did you accidently show us one part of the drawing , or on purpose, you are clearly a fast learner after the Ryger thing. Don't know what to make of the cavity below the port.
Is that what we are supposed to be discussing?

[Flettner]

Fletto, you're a legend in getting things done. Is there something in the water over there or the bubbly hot mud?

The only thing I can suggest is that instead of just throwing that master in the bin, chuck it in the fire. Use it twice. Nice and dry, it'll burn beautifully. Remember, FTE !! :devil2:

When I say the bin, I do mean the bin on the shelf, It will be a backup if things go badly wrong:laugh:
And it might well be modified for version two and then again for version three but it's not used in the actual pattern.

[Flettner]

Hey Flettner , did you accidently show us one part of the drawing , or on purpose, you are clearly a fast learner after the Ryger thing. Don't know what to make of the cavity below the port.
Is that what we are supposed to be discussing?

Opps, the cats out of the bag! Yes this is a Ryger inspired cylinder but different. This cylinder is to bolt on to the oil less bottom end I've made. It will all become clear (ish) as the pattern builds. I only get evenings to work on it as we are real busy at work (building gyro's as it happens). Still what else is there to do on these long cold dark TVless evenings? Yes, stay by the fire :laugh:
Augmented flow.

[WilDun]

Good to see you back on this thread, thought that you may have picked up a bad dose of "Rygermania" and were laid up.
I never even heard of Ryger till a couple of weeks ago (haven't been going to the ESE thread - just learning the basics of patternmaking etc. in my garage).
I did a little bit of research on the Ryger (details pretty sparse) but it seems to me that they are using a modified version of what we used to call "cross scavenging" employed by our little model aircraft engines of the late fifties and early sixties!
Then again I could be totally wrong of course!

I sure wish you luck with your oil less bottom end though, (it's amazing the great strides which have taken place in the last few weeks in lubricaton!).
I don't need to wish you luck with the corebox and patternmaking which is as good as ever. It would be nice to have a finely detailed description of your cylinder design though ..........no? - ah well!

:rolleyes:

[Flettner]

Good to see you back on this thread, thought that you may have picked up a bad dose of "Rygermania" and were laid up.
I never even heard of Ryger till a couple of weeks ago (haven't been going to the ESE thread - just learning the basics of patternmaking etc. in my garage).
I did a little bit of research on the Ryger (details pretty sparse) but it seems to me that they are using a modified version of what we used to call "cross scavenging" employed by our little model aircraft engines of the late fifties and early sixties!
Then again I could be totally wrong of course!

I sure wish you luck with your oil less bottom end though, (it's amazing the great strides which have taken place in the last few weeks in lubricaton!).
I don't need to wish you luck with the corebox and patternmaking which is as good as ever. It would be nice to have a finely detailed description of your cylinder design though ..........no? - ah well!

:rolleyes:

No problem Will, I'll post pictures as I go.
Exhaust ports being made, the tapered bits on the end are core prints, you will see later how they are usefull for holding the core in place.
Yes I know they look like a couple of knobs:laugh:
I like to use macrocarpa, I saved some wood from a tree I cut down a few years ago the rest went to fire wood. It smells gooood, is dry and stable.

[WilDun]

No problem Will, I'll post pictures as I go.
Exhaust ports being made, the tapered bits on the end are core prints, you will see later how they are usefull for holding the core in place.
Yes I know they look like a couple of knobs:laugh:
I like to use macrocarpa, I saved some wood from a tree I cut down a few years ago the rest went to fire wood. It smells gooood, is dry and stable.

Ok, Macrocarpa is about the only one I haven't tried and I guess the most easily obtained! I have got an assortment of timber trial pieces here and hope to settle on one.

Tapered coreprints are interesting - guess that's to locate the patterns axially? - rude, crude? well, not really as long as they are portrayed pointing the way they are, but definitely not as crude as another poster here (pretty sure his name starts with H)!
:laugh:

Still don't know whether my assessment of the Ryger is reasonably correct or not though, (guess I'm probably being a bit simplistic) - no doubt we'll find out one day and bucket racing (not to mention the survival of the two stroke in general) will be changed forever ie. if they change the rules to encourage experimenters.

315123

[WilDun]

No problem Will, I'll post pictures as I go.
Exhaust ports being made, the tapered bits on the end are core prints, you will see later how they are usefull for holding the core in place.


Now that I have finally got my old mind round to understanding what type of engine you are casting/constructing, the great pile of bits of information floating around in my mind are now starting to fit together! :yes:

[Michael Moore]

here's a video on the process

http://www.nopatech.com/en/

I can see where a DIY mold could be done a la nopatech with hardened sand and hand tools/die grinder, but I suspect it would largely be for fairly simple castings without any delicate features. I noticed in the video that the surface finish wasn't too wonderful.

Of course, if the first pour fails, or you want more than one part, you get to carve it over (and over and over) again until you get it right and/or you get the number of parts you need.

With a 1/16" accuracy you might want to do this on a DIY CNC router table instead of inside your VMC. Crumbled sand mixed with way lube might not be too good for the machine. :)

cheers,
Michael

[ken seeber]

More foundry fire safety stuff

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[WilDun]

:killingme:

[Flettner]

Moving along with the plug ( fiberglass terms )

[husaberg]

Moving along with the plug ( fiberglass terms )

What do you think about raising the bottom of the EX port looks like you would still have ample port area anyway.
I am picking with the angle of the tranfers they are pointing up pretty near the top of the EX height.
If you raise up the bottom of the EX port you can fit in a few more transfers under the EX either side?

[WilDun]

What do you think about raising the bottom of the EX port looks like you would still have ample port area anyway.
I am picking with the angle of the tranfers they are pointing up pretty near the top of the EX height.
If you raise up the bottom of the EX port you can fit in a few more transfers under the EX either side?

Looks like Flettner's engrossed in something somewhere else, in fact you can bet he is! Pity that he has to be the only one really into foundry work big time.

There are one or two others who are actively into foundry stuff, doing quite a bit of sterling work and look in occasionally, then of course there are a couple of dabblers (like me) who occasionally have a go, but still need their hands held! - that's about all I guess.
Looks like even Yow Ling (who started the thread) has abandoned it! but I'm sure he is pretty well engrossed in"Bucketeering" at the moment.

I have done sweet FA just lately except fill my workshop with wood shavings from experimental patternmaking and trying to bring some of my machinery (workshop) back to useable condition again.

All goes to show that foundry work and casting is really just a passing interest for the great majority, so unless it's a viable commercial enterprise as well, very few people, even though they might be interested, would consider it as a hobby.
It is quite a hassle to set up (unless you're passionate about it) and to most just isn't cool, because it can't be bought as a kit in a package with a fancy wrapper I guess!

People who make jewellery/precious metal etc. and people who build model engines, trains and the like. seem to be the only hobbies really into foundry stuff nowadays.
:scratch:
Anyway, here's hoping!

[Frits Overmars]

Looks like Flettner's engrossed in something somewhere elseI guess I am to blame for that...

[Flettner]

Looks like Flettner's engrossed in something somewhere else, in fact you can bet he is! Not so good is the fact that he is really the only one here who is into foundry work big time, more or less keeping this thread alive - all very sad, but I guess that's just how it is.

There are one or two others who are actively into foundry stuff, doing quite a bit of sterling work and looking in occasionally, then of course there are a couple of dabblers (like me) who occasionally have a go, but still need their hands held! - and that's about it I guess.
Looks like even Yow Ling (who started the thread) has abandoned it! but I'm sure he is pretty well engrossed in"Bucketeering" at the moment.

I have done sweet FA just lately except fill my workshop with wood shavings from experimental patternmaking and trying to bring some of my machinery (workshop) back to useable condition again.

All goes to show that foundry work and casting is really just a passing interest for the great majority, and unless is a viable a commercial enterprise as well, very few people, even though they might be interested, would consider it as a hobby.
It is quite difficult to set up of course and unless you're passionate about it, not worth the hassle - just isn't cool because it can't be bought as a kit in a package with a fancy wrapper I guess!

People who make jewellery/precious metal etc. and people who build model engines, trains and the like. seem to be the only hobbies really into foundry stuff nowadays.
:scratch:
Anyway, here's hoping!

Yes, sorry, I've been a little tied up as it were. I have though been giving the little cylinder some serious redesign though, just a few little changes to make it more adjustable when I'm wanting to try different setups on the same casting. I'm sure I think I know what I want:rolleyes:

[WilDun]

Yes, sorry, I've been a little tied up as it were. I have though been giving the little cylinder some serious redesign though, just a few little changes to make it more adjustable when I'm wanting to try different setups on the same casting. I'm sure I think I know what I want:rolleyes:

Ok Guys, thanks for the replies, - just thought it might be another case of the "Marie Celeste" - came aboard and no one home! - feel better already!
:msn-wink:

[Flettner]

Well it all ended up out in the paddock!! I didn't wait long enough to for the mould release to set, so the jolly thing stuck together, bugger. But as it happens I've changed my mind on how the seconary transfers work anyway so I'll start again with this new system.

[WilDun]

Well it all ended up out in the paddock!! I didn't wait long enough to for the mould release to set,

That's too bad, at least you've got a paddock for it, I have nowhere but the wife's flower bed! - she is nagging me to get things tidied up around the house ...OR ELSE! .........they just don't understand, do they!
My son who lives overseas has a little Bach with a big garage down the coast and I've been toying with the idea of moving my operations down there - nobody to bother me there, peace to do as I please!

Hope your stuff works out and also that you get to grips with the Ryger.

[Flettner]

We can rebuild it, I decided to have the afternoon off to finish the core plug. Now after some more painting and sanding I will build the core box up from this core shape.

[Yow Ling]

Its been a while since I posted anything here. My foundry got stuck on a few basic problems, the first was I couldnt cut up the aluminium ingot into peices that would fit in my crucible. I solved this last week when I bought an old power hacksaw, to give you an idea of scale the blade is 350mm long

315599

The other and much bigger difficulty is in the patternmaking department, if you cant do woodwork you are kinda screwed, plus Im not keen on sawdust for healthy reasons. I looked at different ways of doing things and watched a Chinese video on making polystyrene patterns, they dipped them in a slurry then vibrated them into a fluidised bed of sand which packed in pretty well , the slurry wall stopped the sand collapsing into the cavity when the metal was poured. They made pretty nicelooking castings.

My plan is to make a polystyrene part using hot wire cutters and encase the poly part in CO2 sand so I wont need the slurry .

I built a wire cutter and had a test cut tonight, The wire is just stainless lockwire and hooked up to a 26v transformer with a variac , 11 volts will make the wire red hot. for the test I just took a head gasket and traced around the edges with the wire. The part I made is a bit of a pigs ear but i think it will work out ok in real life

315600
315601

[Flettner]

Its been a while since I posted anything here. My foundry got stuck on a few basic problems, the first was I couldnt cut up the aluminium ingot into peices that would fit in my crucible. I solved this last week when I bought an old power hacksaw, to give you an idea of scale the blade is 350mm long

315599

The other and much bigger difficulty is in the patternmaking department, if you cant do woodwork you are kinda screwed, plus Im not keen on sawdust for healthy reasons. I looked at different ways of doing things and watched a Chinese video on making polystyrene patterns, they dipped them in a slurry then vibrated them into a fluidised bed of sand which packed in pretty well , the slurry wall stopped the sand collapsing into the cavity when the metal was poured. They made pretty nicelooking castings.

My plan is to make a polystyrene part using hot wire cutters and encase the poly part in CO2 sand so I wont need the slurry .

I built a wire cutter and had a test cut tonight, The wire is just stainless lockwire and hooked up to a 26v transformer with a variac , 11 volts will make the wire red hot. for the test I just took a head gasket and traced around the edges with the wire. The part I made is a bit of a pigs ear but i think it will work out ok in real life

315600
315601

That hacksaw is an oldie.
The Bandsaw I use in my workshop was made in Christchurch (1950 somthing) back in the day when we used to make stuff.

[Yow Ling]

That hacksaw is an oldie.
The Bandsaw I use in my workshop was made in Christchurch (1950 somthing) back in the day when we used to make stuff.

Old and killer heavy, could only move it a few feet at a time between breaks, getting it out of my trailer was a real act, had to use a jack to get it over the doorstep

[Kickaha]

Old and killer heavy, could only move it a few feet at a time between breaks, getting it out of my trailer was a real act, had to use a jack to get it over the doorstep

You have to do shit the hard way, give me a call next time

[ken seeber]

Its been a while since I posted anything here. My foundry got stuck on a few basic problems, the first was I couldnt cut up the aluminium ingot into peices that would fit in my crucible. I solved this last week when I bought an old power hacksaw, to give you an idea of scale the blade is 350mm long

What you can also do is to use a 9 inch angle grinder with a masonry disc, cuts alum easy. You could either cut it all the way thru, or cut down 10 mm or so on one side only to create a stress raiser and with a sledge hammer give it a smack, cut side down


I reckon the styrene fumes will be worse than the sawdust, so definitely cast outside with the wind blowing towards your least most popular neighbour. You know, the one who reckons you have issues. :mad:

[husaberg]

We can rebuild it, I decided to have the afternoon off to finish the core plug. Now after some more painting and sanding I will build the core box up from this core shape.

I have came up with a name Neil
With a bit of luck it might just fly
315602315603

[ken seeber]

We can rebuild it, I decided to have the afternoon off to finish the core plug. Now after some more painting and sanding I will build the core box up from this core shape.

Mumma mumma mate, you're the man ! Can't wait. :woohoo:

[WilDun]

Yow Ling,
I'm glad to see you're still with us and still interested - to be honest I don't think you'll regret getting that monster of a hacksaw and it'll be useful till you are too old to use it! (and beyond).

Flettner, I wasn't going to say anything until I've got my head around that 'thing' and to be honest I'm still a bit in the dark, so I'll wait a while longer and see how things pan out!
In the meantime I'll just go along with Husa - you know, the "elephants can fly" theory!

[Flettner]

I thinks it looks more like Zurg, space ranger Buzz Lightyears nemissis. If you you have grand kids you will know who I'm talking about:facepalm:
Anyway, the start of the core box and no I don't know what it will look like yet it will just evolve.
For those unsure as to how it works, there is a peice missing, oh, just the cylinder itself. Can't show that bit off just yet.

[husaberg]

I thinks it looks more like Zurg, space ranger Buzz Lightyears nemissis. If you you have grand kids you will know who I'm talking about:facepalm:
Anyway, the start of the core box and no I don't know what it will look like yet it will just evolve.
For those unsure as to how it works, there is a peice missing, oh, just the cylinder itself. Can't show that bit off just yet.
http://www.comparestoreprices.co.uk/images/to/toy-story-basic-action-figure-zurg-1.jpg

[Flettner]

Slowly encasing Zurg in wood and bondifill.

[WilDun]

So, we're looking at a corebox under construction?

[Flettner]

So, we're looking at a corebox under construction?

Yes, using old bit's of bed head and bondifill.

[Flettner]

Cavity forming, next a lid.

[WilDun]

Cavity forming, next a lid.

Not your average easy two piece corebox I must say - hope it will be used for more than one core!
Guess the 'inlet'? passages have a fair draught angle on the sides, or is it to be a multi piece corebox so making that unnecessary?- I just can't see any draught in the photos, but maybe it's three piece?

[Flettner]

Not your average easy two piece corebox I must say - hope it will be used for more than one core!
Guess the 'inlet'? passages have a fair draught angle on the sides, or is it to be a multi piece corebox so making that unnecessary?- I just can't see any draught in the photos, but maybe it's three piece?

It's a six peice, see the studs holding it together. It will be a seven peice with the lid.
It will be used at least twice as it's first job will be to make a resin copy of the core to build the pattern up from, this core shape will be imbeded into the pattern with the core prints sticking out (tapered core supports).

[WilDun]

It's a six peice, see the studs holding it together. It will be a seven peice with the lid.
It will be used at least twice as it's first job will be to make a resin copy of the core to build the pattern up from, this core shape will be imbeded into the pattern with the core prints sticking out (tapered core supports).

Yes, I can remember you doing that using the "beads & bog" process on the 360? - will look forward to seeing it all happen and who knows, I might even try something like that one day in the future, probably something much simpler though.
Must say I'm finding it a little easier to get my head around this time, took a lot of learning to get the "inside out" concept, but I think I'm now getting a grasp!

[WilDun]

Thread is slowing down again!:facepalm:

Had a lot of time off from all this stuff lately with visitors staying etc. so I'll have to get back into the patternmaking learning curve and be ready to do some more casting as the weather is beginning to improve.

The Ryger thing is still way above my head, so I'll try to stop myself trying to figure it all out and keep concentrating on designing and casting more mundane stuff drawn up by myself (not into doing stuff from plans or other peoples designs), although I will of course probably use them for inspiration.

Still plodding on and using Flettner and Manolis etc. as a good source of knowledge and inspiration.

[Flettner]

Will, the core box is finished but I can't take any photos using my (wifes) camera as I've lost the data card.
BUT I do now have one of those phones that has a small TV screen, I don't know how it works, apparently it will take photos. Imagine that a phone with a camera in it, what will they think of next:laugh: All kidding aside, I do take photos with it but I'm not sure how to transfer them, one of my kids will know (or perhaps even the grand kids:laugh:)
Any way Zurg has done his job and we are finished with him, off to the shelf.

[Flettner]

Wow, look at that straight from my TV / Phone.

[Flettner]

And again, I'm getting good at this data transfer stuff

[WilDun]

Will, the core box is finished
Any way Zurg has done his job and we are finished with him, off to the shelf.

Did you only do two cores? - then I guess it's easy to take Zurg off the shelf when necessary.

It would seem that you have a finalised design in your head, otherwise you wouldn't have gone to all the trouble of making a fairly complicated corebox like that.

[Flettner]

Will, nothing is finalised, you just got to start somewhere:laugh:
Although I do have a rough idea as to what I want, I think.
I've just poured a new Zurg, will open the core box tomorrow and see what pops out, :eek:
Now the real pattern making begins, beads and hot glue gun at the ready.

[Flettner]

Zurg replica, made in casting resin.

[WilDun]

Zurg replica, made in casting resin.

I see you are using good "premium" quality bog!
You seem to be using quite a few varieties of wood in that corebox too - which one do you find to be best for machining?
Guess I shouldn't pry as to how that inlet/transfer system works, (it's way above my head so far), but it sure looks interesting, I have some clues but not quite enough to finalise it all in my mind!
I do hope though that it doesn't need conventional chambers as well! - would mean a lot of bulky pipework and accessories to be added I should think, (but then of course I realize it's all still in the early experimental stages).

[Flettner]

I see you are using good "premium" quality bog!
You seem to be using quite a few varieties of wood in that corebox too - which one do you find to be best for machining?
Guess I shouldn't pry as to how that inlet/transfer system works, (it's way above my head so far), but it sure looks interesting, I have some clues but not quite enough to finalise it all in my mind!
I do hope though that it doesn't need conventional chambers as well! - would mean a lot of bulky pipework and accessories to be added I should think, (but then of course I realize it's all still in the early experimental stages).

The wood I'm using is just what I had around, some Rimu I think and some pine. Kiln dried pine (or just old stable dry pine as you might find in junked couches etc ) is best to work with and glue / bondifill.

How does it work? Don't laugh, it's just an experiment, uses a high pressure crank case pump. I can do this because there is now no crank case involved and under the piston I can stuff right up. This is not ideal as to total gas transfer (high pressure, low volume) but this system has reeds to allow augmentation ie draw more fuel air in after the initial charge is shot out into the chamber, that part is not visible yet.
The "ears" are extra high timing ports (with non return valves, reeds) that should allow more air only gas flow at higer engine speeds. The short chamber under the reeds will pressureise with exhaust gas then as cylinder pressure drops will empty into the cylinder. This and chamber activity should help these ports draw.
The combustion chamber part of the cylinder is missing as it will be bolted on afterwards with the in cylinder ring sandwiched in, piston will have no rings.
Clear as mud?

[WilDun]

The wood I'm using is just what I had around, some Rimu I think and some pine. Kiln dried pine

How does it work? .......... uses a high pressure crank case pump. I can do this because there is now no crank case involved and under the piston I can stuff right up. This is not ideal as to total gas transfer (high pressure, low volume) but this system has reeds to allow augmentation ie draw more fuel air in after the initial charge is shot out into the chamber,........
The "ears" are extra high timing ports (with non return valves, reeds) that should allow more air only gas flow at higer engine speeds. The short chamber under the reeds will pressureise with exhaust gas then as cylinder pressure drops will empty into the cylinder. This and chamber activity should help these ports draw.........
piston will have no rings.

Clear as mud?
Kauri seems to be a good fine grained timber which turns quite well, but there seems to be quite a wide variety of pine which I have to sort through, some useless some good, but I'll get there.

Yes, clear as mud for the moment! but I now have it registered in my mind which will tend to quietly work on it without my knowledge. but I suspect that harmonics comes into play here big time! (and that's something which I know virtually nothing about).

However,it seems that there is also a missing link somewhere, which I probably didn't discover because I stopped looking at the ESE thread way back ( in order not to clutter my feeble brain with too much stuff) and it would seem that I missed out all the important stuff that came online.

So, I'm completely in the dark regarding the oilless "crank"? or whatever it actually might be. I did think it was a joke at first!
In fact, I'm still not fully convinced that it isn't! - but if it is for real, (and going by the sparse information I have), then it's some sort of "straight line" mechanism driving an output shaft and which involves gears or levers, but I can't for the life of me think of anything transmitting straight line forces to a revolving shaft which could run without oil! - but maybe they are seperated from the gases by labyrinth seals? - or again, maybe there are miracles!

Unfortunately, I am not a great fan of going back and plodding my way through all the back posts to pick out all the relevant material from reams of sundry tuning stuff, also other crap - I need to use my precious time in the workshop and not on the computer, this is the only time I have left, after family matters etc.

Regarding the chambers with the reeds, ....... I seem to remember that the early racing two strokes of the sixties (Suzuki, MZ etc.) tried using the back boost port in this fashion - ie. it opened ahead of the exhaust port to pressurise the crankcase and force the charge into the cylinder but didn't (as far as I know anyway) take in extra air into the cases.

I also seem to remember that some model aircraft engines from that era used something called "supplementary sub piston air induction" - the air came in under the piston skirt when it momentarily exposed the exhaust port (it was just a port - no pipe). - that idea seemed to disappear though!
These arrangements of course were not the same as your idea here, but possibly they may have a few similarities.

I really don't expect that you'll want to give away all your secrets either! so I need to assure you that I won't tell a soul, (not that anyone in my family would even notice if I did tell them - all bean counters etc.).

:niceone:

[Flettner]

Will, you are right, there is a little more I'm not saying but I need to be sure of what I'm saying before I open my mouth.
I'm organizing the water core at the moment, a little tricky.

[Kickaha]

I dont rember seeing it on here but this is quite cool, Gilera 4 being made from a 175 single, bit of casting in this
http://www.pacarweb.com.ar/Cuatroingles.html

[husaberg]

I dont rember seeing it on here but this is quite cool, Gilera 4 being made from a 175 single, bit of casting in this
http://www.pacarweb.com.ar/Cuatroingles.html

Thats pretty incredible. Using the cases gives it a little air of authenticity as well
Neil how come you never "adjust it the conjunts"
A French guy that's something like nouieger used to do similar and more he had Jow Crai sold on a four he made but Joe couldn't get it past the board
I will post it in multispage when JAW has gone.

[Flettner]

So, I'm completely in the dark regarding the oilless "crank"? or whatever it actually might be. I did think it was a joke at first!
In fact, I'm still not fully convinced that it isn't! - but if it is for real, (and going by the sparse information I have), then it's some sort of "straight line" mechanism driving an output shaft and which involves gears or levers, but I can't for the life of me think of anything transmitting straight line forces to a revolving shaft which could run without oil! - but maybe they are seperated from the gases by labyrinth seals? - or again, maybe there are miracles!


Like this Will? This is the bottom end I will be using, there is witch craft and hobbits inside;), also an oil pump. The tube does 52mm stroke, piston will be attached to the tube. Cylinder is designed to bolt on the top (four 8mm threaded holes). Bottom end is fully oiled, top end is dry, fuel only, nothing touching in the top end. In this unit I can adjust the possition of the stroke on the fly by 2mm. It certainly isn't pretty:yes: Oh and a plastic flywheel.

[WilDun]

I dont rember seeing it on here but this is quite cool, Gilera 4 being made from a 175 single,

Helluva dedication required there! - probably harder to do than starting something from scratch!

[WilDun]

Like this Will? This is the bottom end I will be using, In this unit I can adjust the possition of the stroke on the fly by 2mm. It certainly isn't pretty:yes:

Yes, I remember now! the crank with the 'beam' or 'rocker" type operation, straight line? - I think there was a swinging link at one end?
It's fun when all these little (apparently orphan) pictures floating in your head decide to come together! - hope I'm assembling them (ie the pictures) correctly!
The plastic flywheel could be forgiven ie if it's not PVC!

[speedpro]

Like this Will? This is the bottom end I will be using, there is witch craft and hobbits inside;), also an oil pump. The tube does 52mm stroke, piston will be attached to the tube. Cylinder is designed to bolt on the top (four 8mm threaded holes). Bottom end is fully oiled, top end is dry, fuel only, nothing touching in the top end. In this unit I can adjust the possition of the stroke on the fly by 2mm. It certainly isn't pretty:yes: Oh and a plastic flywheel.

Nothing unusual for you then. Wil' missed the "plastic flywheel" joke.

[WilDun]

Nothing unusual for you then. Wil' missed the "plastic flywheel" joke.

Well, as I don't often go there, I'm not privvy to all the wise and intellectual 'goings on' you get in ESE and the mind tends to become a little dull! but I'm sure you can make allowances for me and probably talk a little more slowly so I can 'get it'.
Maybe I should do a long and 'protracted' study on it!
:rolleyes:

[TZ350]

(Insert long sigh here) I hate, I hate to ask this, because I know I've seen the answer somewhere, ... but could one of you skilled info-locators please once-and-for-all-time give a detailed step-by-step set of search directions here, to show us how to find something WITHIN the ESE superthread.

Hi Will I know what you mean about the ESE thread, go to Seattle Smitty's original post, its the start of a short thread with many tips on how to search and find good stuff on the ESE thread or any thread for that matter.

[WilDun]

Hi Will I know what you mean about the ESE thread, go to Seattle Smitty's original post, its the start of a short thread with many tips on how to search and find good stuff on the ESE thread or any thread for that matter.

Thanks TZ,
I have always been interested in the ESE thread, but with nothing to relate to (as in having an actual bike) it is hard to keep up with the play and so I don't have the incentive to get deeply involved, but I will keep looking in so as not to miss out in any new developments and of course I'll check out the thread you have mentioned.
As you know, I am plodding on with the foundry stuff, and have made that my priority - I need to manage my time from now on and that will mainly be juggling between family and workshop/foundry, with not a lot of time for learning heaps of other new stuff. - I really need to rewind about 20 years to try and do all the things I would actually like to do!

[Arifidyan]

I saw a post on the first pages, to make the molding cores using 'bondi fill'. Is it some sort of gypsum? is there a more general terms about bondi fill?

Thank you! :)

[Yow Ling]

I saw a post on the first pages, to make the molding cores using 'bondi fill'. Is it some sort of gypsum? is there a more general terms about bondi fill?

Thank you! :)

Hello Arifdyan, Bondi is the filler used to repair dents in cars before they are repainted , it comes in a tin with a small tube of hardener. When it is set it is like a hard plastic that can be sanded , some people call it Bog, just google automotive body filler

[WilDun]

I saw a post on the first pages, to make the molding cores using 'bondi fill'. Is it some sort of gypsum? is there a more general terms about bondi fill?

Thank you! :)

It is just ordinary car body filler or "bog" - as we usually call it here.

(Sorry i see that Yow ling has already answered that question!).

[Flettner]

Don't worry Will, things are still happening in the pattern shop. I've sort of got a water jacket shape made but I wasn't sure how I was going to hold it in place ie where the core prints were going to be placed. This all depends on how the sand mold is taken apart and re assembled (without the pattern inside). When I remember how this new cellphone thing works I'll post more pictures.

[WilDun]

Don't worry Will, things are still happening in the pattern shop. I've sort of got a water jacket shape made but I wasn't sure how I was going to hold it in place ie where the core prints were going to be placed. This all depends on how the sand mold is taken apart and re assembled (without the pattern inside). When I remember how this new cellphone thing works I'll post more pictures.

Look forward to hearing and seeing what is happening at your workshop.

I'm also trying to get my head around the Ryger thing on ESE now and I am beginning to form my own opinions on it - beginning to favour something based on the working two stroke by that guy in Oz, which is running with a seperate crankcase (this one I think I mentioned in "Oddball" way back). - come to think of it, he has a Dutch name too! ....... I wonder?

I'm pleased you mentioned over there (in ESE) about this foundry thread - also not forgetting the "Oddball" thread for other stuff (like the Ryger maybe? - too late there! :laugh:) - maybe some people could mention there that they have posted something on foundry work here, or some innovative ideas on the "Oddball" thread so keeping everything seperated and prevent a "hodge podge" of good ideas being swept away and swallowed up by the giant, fast moving ESE thread. this could allow the ordinary tuners to have a say on their standard stuff.
It might take a little effort to organise of course and I don't really have a voice over there - just an "also ran" I'm afraid.

Anyway, that was my idea from way back but I'm sure it would take some changing - I hope it hasn't turned into a thread where the record number of postings has become the most important target! (this statement inspired by the recent comment made by Frits).
The ESE thread reminds me on my workshop, ie full of good stuff, but can I find it?! :no: clutter, clutter and more clutter :rolleyes:

[Peiter]

I'm gathering all kinds of pictures / info on the 3d scanning / CAD / 3d printing and PLA investment casting of my cylinder, I'll try to post it this evening (Dutch time :) )

[WilDun]

I'm gathering all kinds of pictures / info on the 3d scanning / CAD / 3d printing and PLA investment casting of my cylinder, I'll try to post it this evening (Dutch time :) )

Peiter, - That sounds good to me!

[Arifidyan]

Hello Arifdyan, Bondi is the filler used to repair dents in cars before they are repainted , it comes in a tin with a small tube of hardener. When it is set it is like a hard plastic that can be sanded , some people call it Bog, just google automotive body filler


It is just ordinary car body filler or "bog" - as we usually call it here.

(Sorry i see that Yow ling has already answered that question!).

Big thanks to answer. :headbang::headbang:

My 135cc project :
(photos attached)

[WilDun]

My 135cc project :
(photos attached)

I'm not really understanding that core you have made (in the pic) - especially the 'indents' you have in the porting area, but maybe someone can explain (I seem to have missed the plot somewhere !)

[husaberg]

I'm not really understanding that core you have made (in the pic) - especially the 'indents' you have made in the porting area, but maybe someone can explain (I seem to have missed the plot somewhere !)

They are core prints that the transfers attach to. They allow the correct position and orientation to be achieved when the sand or resin core is made and assembled. In the picture You are looked at the female indentation for the transfers, in this case the transfers will carry a male protuberance.

316229

[WilDun]

They are core prints that the transfers attach to. They allow the correct position and orientation to be achieved when the sand or resin core is made and assembled. In the picture You are looked at the female indentation for the transfers, in this case the transfers will carry a male protuberance.


I knew that I wouldn't 'get it' even though the obvious answer was staring me right in the face! :facepalm: - there you go, we learn something new every day - that's really what life is all about!

Come to think of it, reminds me what Ronald Reagan said when he knew that his Alzheimer's was starting to set in - he said " you get to meet lots of new people every day" :confused:

[Frits Overmars]

.. reminds me what Ronald Reagan said when he knew that his Alzheimer's was starting to set inThree advantages of Alzheimer: you meet new people every day, you can hide your own easter eggs, and you meet new people every day.

[WilDun]

Three advantages of Alzheimer: you meet new people every day, you can hide your own easter eggs, and you meet new people every day.

Yes, probably, but how did this discussion start?.....and .......now what were we talking about?

[polinizei]

Hi guys, I want do introduce my longtime project.
60x66 Bore for my old 4 gear shifted scooter.
I will use CAD and my Zortrax 3D printer.
Since my beginning, I spend more than 1000 hours in cad modelling, so it’s a bit virtual for a while.
The next big thing is that Ryger Stuff, that keeps me away finishing what I have begone…

Here are some Pics.

[polinizei]

More Pics (and more text)

[WilDun]

More Pics (and more text)

All looks good
I think, as you said you should finish it first - seeing that you have actually begun this project (instead of becoming one of the crowd trying to be first with a "Ryger" :)

You have obviously invested heavily in software and printer etc. but will you still need to clean up the PLA pattern by hand before use? and will you be casting the stud holes as well, ie instead of drilling solid metal?
So far it looks ok. but then there's the casting part to be done as well! - Of course, you may already have experience in doing that, I don't know.
If you haven't though, I feel that you should concentrate on learning that first (before the Ryger) as it will be just as important as the pattern work and will take a lot of practice.

I'm slowly learning to do it all the old way with limited equipment, (I will probably never be able to afford new equipment but I only do it for enjoyment). Moulding and casting, whatever equipment you may have, still takes some learning and depends a lot on "touch and feel".
I think it will be a great pastime once I've mastered it all!

Good luck with your endeavours - they seem to be going well so far.

[Peiter]

Polinzei, cool looking stuff! :)

Below is my first part on the PLA made cylinder and casting it;
At first I wanted to buy a cylinder kit made by Stage6 or a Malossi speed 7T which all perform reasonably well.
However, in december 2014 I stumbled upon a guy on google who was casting an aluminium piece directly from his PLA printed 3D model (http://3dtopo.com/lostPLA/).
This made me interested in the subject and together with a metal foundry nearby where I live, we tried a sample ourselfs. It turned out that PLA will melt away 100%
without residues, so the method was indeed quite good to cast cylinders!

Together with a good friend we then formed the idea to start designing a cylinder ourself where we could work around the following:
- The original stud size is 56x56 with 7mm studs, this pattern is too small for a 47.6 bore cylinder to shape it correctly at the exhaust and b-port.
- Most aftermarket cylinders have the exhaust channel at a straight angle whereas we have tried to obtain the desired 20-25 degrees (if I recall it correctly).
- Cooling of most cylinders for a Derbi engine is asymmetric on one side of the exhaust channel.

First, I started making silicone molds of all sorts of cylinders I could get my hands on, a friend's 22 hp 50cc, an Aprilia RSA, a Honda 2007 a-kit, a KTM 125, etc..
(in the picture below are only a few of the silicones, I have enough to fill my desk :))
316263
With these molds, I went to a Fablab where they had a reasonable 3D scanner and I scanned the molds with an accuracy of (If I recall it correctly..) 0.1 mm.
Next, I sat together with my friend and given our appetite and enthusiasm to discover things ourselfs (in some people's eyes stubbornness), we decided to go with the Honda port lay-out as shown in the images.
316260316261316262
The Honda cylinder had the A-port its edge nearest to the B-port almost perpendicular to the bore and aimed at the other side. We decided to go with a more common direction of aiming the A-port further towards the C.
The axial angles are set to about 22 deg. for the A-port, 8 deg. for the B port and 50 deg. for the C-port.

After designing the cylinder in CAD, it was time to print it in PLA. As we had to remove / clean the white shell after casting, we decided to remove the "roof" above the exhaust port such that we could thoroughly clean the cylinder.
316265
Inherent to the FDM process used by our Ultimaker 2, overhangs and roofs larger than 50 or 60 degrees require support material to deposite the material during printing. Therefore, we had to design the cylinder in such a way that it was printable and all the support material was removable.

I'll elaborate on making the design printable and the actual casting next time, hopefully you guys like it!

cheers,

Peter

[WilDun]

So you guys will both be using the 'lost PLA' method of casting? - sand/plaster I suppose?
Now I'm really starting to feel old, but at least I have heard something about that process! :rolleyes:

[Peiter]

Hi Wil,

If I can judge it correctly, Polinzei has gone with printing tools (I don't know the right word) to form his sand cores in. Together with the foundry, I decided to go the lost PLA way, where the printed part will be the actual cylinder later on. Wax risers were attached to the PLA cylinder and the mold was then dipped in a liquid, coated with fine ceramic dust, dried, dipped again, coated again, etc. until the layer was thick enough. Next, the PLA and wax was melted away during a final step, after which the cylinder could be cast.

Excuse me if the lay out is messy, I am typing this message on my phone 😊.

[ken seeber]

Hi Wil,

Next, the PLA and wax was melted away during a final step, after which the cylinder could be cast.

Excuse me if the lay out is messy, I am typing this message on my phone ��.

Peiter, thanks for your contributions.
Did you have any issues with the PLA cracking the investment during melt and what temps did you used for melting and burnout?
Also, another question, what shrinkage allowance did you make and/or what was the overall shrinkage, eg from a dimension on the PLA to the same dimension in the cast aluminium.
Your phone message is just fine. Keep it up. :yes:

[WilDun]

Hi Wil,
If I can judge it correctly, Polinzei has gone with printing tools (I don't know the right word) to form his sand cores in.

Coreboxes?
I suppose that as the printer/ 'lostPLA' system becomes more popular then coreboxes will be out, but nothing ever goes away completely and I'm sure that some of us will just continue to use that method in conjunction with Co2/ Sodium Silicate moulds and cores - it's maybe a little more 'hands on' and takes more time to do, but cheaper and still fine for a home workshop such as mine where time is not money! - I must say though that it's still very interesting to me.

Ken, I have heard of ceramic shells cracking with expanding wax patterns (expansion before melting), but maybe the PLA doesn't expand as much before melting? / burning out?.
Guess it would also depend on the section thickness - a large piece of wax would probably take a little longer to melt, which means it will have more time to expand before that happens.
I wouldn't know how much expansion to expect from PLA though.

[Flettner]

Coreboxes?
I suppose that as the printer/ 'lostPLA' system becomes more popular then coreboxes will be out, but nothing ever goes away completely and I'm sure that some of us will just continue to use that method in conjunction with Co2/ Sodium Silicate moulds and cores - it's maybe a little more 'hands on' and takes more time to do, but cheaper and still fine for a home workshop such as mine where time is not money! - I must say though that it's still very interesting to me.

Ken, I have heard of ceramic shells cracking with expanding wax patterns (expansion before melting), but maybe the PLA doesn't expand as much before melting? / burning out?.
Guess it would also depend on the section thickness - a large piece of wax would probably take a little longer to melt, which means it will have more time to expand before that happens.
I wouldn't know how much expansion to expect from PLA though.

I realy don't understand why these printers aren't used to build the core boxes, now that make a lot more sense.

[husaberg]

<iframe width="560" height="315" src="https://www.youtube.com/embed/bCsg5pQimWI" frameborder="0" allowfullscreen></iframe>
too short...............

[Arifidyan]

Polinzei, cool looking stuff! :)

Below is my first part on the PLA made cylinder and casting it;
At first I wanted to buy a cylinder kit made by Stage6 or a Malossi speed 7T which all perform reasonably well.
However, in december 2014 I stumbled upon a guy on google who was casting an aluminium piece directly from his PLA printed 3D model (http://3dtopo.com/lostPLA/).
This made me interested in the subject and together with a metal foundry nearby where I live, we tried a sample ourselfs. It turned out that PLA will melt away 100%
without residues, so the method was indeed quite good to cast cylinders!

Together with a good friend we then formed the idea to start designing a cylinder ourself where we could work around the following:
- The original stud size is 56x56 with 7mm studs, this pattern is too small for a 47.6 bore cylinder to shape it correctly at the exhaust and b-port.
- Most aftermarket cylinders have the exhaust channel at a straight angle whereas we have tried to obtain the desired 20-25 degrees (if I recall it correctly).
- Cooling of most cylinders for a Derbi engine is asymmetric on one side of the exhaust channel.

First, I started making silicone molds of all sorts of cylinders I could get my hands on, a friend's 22 hp 50cc, an Aprilia RSA, a Honda 2007 a-kit, a KTM 125, etc..
(in the picture below are only a few of the silicones, I have enough to fill my desk :))
316263
With these molds, I went to a Fablab where they had a reasonable 3D scanner and I scanned the molds with an accuracy of (If I recall it correctly..) 0.1 mm.
Next, I sat together with my friend and given our appetite and enthusiasm to discover things ourselfs (in some people's eyes stubbornness), we decided to go with the Honda port lay-out as shown in the images.
316260316261316262
The Honda cylinder had the A-port its edge nearest to the B-port almost perpendicular to the bore and aimed at the other side. We decided to go with a more common direction of aiming the A-port further towards the C.
The axial angles are set to about 22 deg. for the A-port, 8 deg. for the B port and 50 deg. for the C-port.

After designing the cylinder in CAD, it was time to print it in PLA. As we had to remove / clean the white shell after casting, we decided to remove the "roof" above the exhaust port such that we could thoroughly clean the cylinder.
316265
Inherent to the FDM process used by our Ultimaker 2, overhangs and roofs larger than 50 or 60 degrees require support material to deposite the material during printing. Therefore, we had to design the cylinder in such a way that it was printable and all the support material was removable.

I'll elaborate on making the design printable and the actual casting next time, hopefully you guys like it!

cheers,

Peter

This awesome. Did you make crankcase too?

[WilDun]

I realy don't understand why these printers aren't used to build the core boxes, now that make a lot more sense.

Yes, I would agree that it is a good idea too, but whatever you make with a 3D printer will not make a perfect pattern (at least going by some results I've seen from printers) - I guess that will all be resolved eventually, but possibly by some very expensive printers! In the meantime some prints will really need to be tidied up and plastic isn't always the easiest stuff to tidy up (from my experiences)!

But don't get me wrong, I am also a big fan of this method, except that I'll run out of time before it can reach a workshop like mine! :cry:

[polinizei]

My Zortrax M200 prints very good results. (Better than Ultimaker 2)
It prints up to 0,09mm layers.

Its possible to finshing the printed parts with acetone, to geht a shiny gloss.
https://www.youtube.com/watch?v=h2lm6FuaAWI


I like the layer finish for every day parts.

[F5 Dave]

Printer at work costs almost as much to lease as my first house outright. It's not bad. And working as we speak, sadly out of my reach.

[polinizei]

There are lots of printer sevices in the web. So there is no need for your own printer for beginning. But CAD know how is a others thing.

[WilDun]

All sounds very interesting - watched the video on smoothing with acetone and also the one on using epoxy for smoothing but I guess the epoxy would affect the burnout.
I wonder how accurate the printers are for dimensional accuracy, especially after smoothing?

Now you guys will have to see it right through to the final product!
I probably won't be trying a printed pattern or corebox but I will look forward to watching your progress!

But ...... for me, it's back to making wooden patterns.

[polinizei]

I'm envious to all that wooden stuff...
Right now its easier for me, to find time for cad modelling and let the printer do the work...
If bury in the workshop would be an option, I would prefer it.

[Peiter]

The burnout temperature was raised slowly to prevent the ceramic shell from cracking. Eventually, the burn out was at about 500 degrees for 6 hours or so, according to the foundry :).

Smoothing the PLA print is indeed still an issue I'm adressing, as the surface was quite rough in the final aluminium cast part. I have tried a chemical on the PLA but I didn't like it as it softened the part and with epoxy I'm affraid it won't burnout correctly. On the next iteration of my cilinder, I'm going to sandblast the parts softly with glass beads to smoothen the side surfaces of the print.

Polinzei, seeing that you smooth your parts with Acetone, I suppose you are printing with ABS instead of PLA? From what I have heared, ABS wouldn't be suitable to burn-out. You did interest me however to rethink the current lost PLA method and perhaps go ahead and design the core boxes in ABS similar to what you have done :).

[Frits Overmars]

The burnout temperature was raised slowly to prevent the ceramic shell from cracking. Eventually, the burn out was at about 500 degrees...Peiter, in a perfect world those 500° would be Kelvin, but that would be too much to hope for and maybe too cold to burn everything out. So are you talking Celsius (Centigrade is accepted too) or are you referring to this guy Fahrenheit?

[Peiter]

Frits, As I am a mechanical engineer instead of a physicist, I normally refer to Celsius instead of Fahrenheit :). I forgot for a moment about the different conventions around the globe.

The PLA starts melting at 150 to 160 degrees so raising the temperature to 500 degrees Celsius was mainly to fully dry the shell.

[ken seeber]

[QUOTE=Peiter;1130908250]Smoothing the PLA print is indeed still an issue I'm adressing, as the surface was quite rough in the final aluminium cast part. I have tried a chemical on the PLA but I didn't like it as it softened the part and with epoxy I'm affraid it won't burnout correctly. On the next iteration of my cilinder, I'm going to sandblast the parts softly with glass beads to smoothen the side surfaces of the print.

QUOTE]

Peiter, when we bought our Dutch made printer (a Leapfrog Creatr with twin heads) one of the features was that one could print with ABS and use PLA for the supports, this being dissolvable in warm water. Unfortunately this didn't seem to work very well, maybe we just got some crap filament. Seemed to be a nice elegant way to go, printing a lost PLA part especially with a fairly low density infill, say 20%, this would allow the water to penetrate fairly easily. The little experience we have with the "set" investment is that it is like concrete and that not really affected by water, but would certainly need drying out. Other options being HIPS and PVA.
Still, if you have had no real difficulties with melting out, then we might give it another go.
Especially as this Ryger thing is getting simpler by the day....................Frits.:rolleyes:
Thanks

[Peiter]

Hi Ken,

I have never heared that PLA is dissolvable in water, the only (printable) material I know of is PVA.
All my printed cylinders were at around 20 - 25% infill such that it was quite easy to melt away.
As I think I mentioned earlier, I printed the cylinder in sections to avoid support material and glued them together afterwards to form the complete cylinder.
I'll try to make pictures of the cylinder section tonight, that will make it better understandable.

Below is the first version where we suspect that the foundry didn't have to mold upside down long enough such that still some PLA was trapped inside:
316291
The second version, where I also corrected some mistakes in wall thicknesses and stuff was already much nicer:
316292
After some Dremel love and glass bead blasting this turned out perfectly fine in my opinion:
316293

Regarding the Ryger, I am reading everything on team ese .. with interest and I've heared some rumours here in the Netherlands too.
At first I thought, what the heck, just throw this cylinder away and wait for more information such that I can start making something similar.
However, after some thought, I considered I should first finish this piece and gain experience in every part of the process.
When eventually enough information is available I can still go that route and atleast I then know all the potential problems of casting and machining a cylinderkit :)

Cheers,

Peter

[Frits Overmars]

Frits, As I am a mechanical engineer instead of a physicist, I normally refer to Celsius instead of Fahrenheit Keep up the good work, Peiter. I am a physicist who likes to get his hands dirty every now and then :yes:.

[125techdir]

Polinzei
Interesting item, I have been down this route casting ports for a water cooled 125 BSA Bantam racer in steel. When you get to the casting consider the removal of the vitreous coating inside the ports. These have to be removed with shot blasting so you may need special 'tools' to allow you to get into the smaller passages. If you are water cooling the passages may be difficult to get into and clear with an obvious risk of poor cooling.

[WilDun]

Keep up the good work, Peiter. I am a physicist who likes to get his hands dirty every now and then :yes:.

To me, this forum is good in that even people like myself who only play around with different processes, can get help and get to talk to people with up to date information on various processes which even as recently as 15 years ago was not universally available!

We already have a resident 'wizard' in traditional casting and patternmaking here on the forum (not me, I'm only a peasant boy who just wants to know). He is well versed in and has successfully designed and built a lot of stuff,
He keeps me and others on the right track with our endeavours and no doubt is extremely interested in the work that all you overseas engineers/ physicists/and experimenters (of all kinds) are doing as well - long may it all continue!

Back to bed now - just got up for a drink of water!

And yes, I talk too much! :laugh:

[WilDun]

Polinzei
Interesting item, I have been down this route casting ports for a water cooled 125 BSA Bantam racer in steel.

They are still racing Bantams in the UK? - do they still use the 3 speed box?
Takes me back! I once did up a Bantam for racing (George Todd head and all that) and enjoyed it very much - a water cooled Bantam was my ultimate goal at one stage, (inspired by the Greeves Silverstone), unfortunately that all disappeared when the Suzuki T20 came out!

[125techdir]

They are still racing Bantams in the UK? - do they still use the 3 speed box?
Takes me back! I once did up a Bantam for racing (George Todd head and all that) and enjoyed it very much - a water cooled Bantam was my ultimate goal at one stage, (inspired by the Greeves Silverstone), unfortunately that all disappeared when the Suzuki T20 came out!
We race under the British Historic Racing umberella and yes it is still only a three speed gearbox. Perhaps a bit faster then the Todd head days but still just as much fun.

[breezy]

They are still racing Bantams in the UK? - do they still use the 3 speed box?
Takes me back! I once did up a Bantam for racing (George Todd head and all that) and enjoyed it very much - a water cooled Bantam was my ultimate goal at one stage, (inspired by the Greeves Silverstone), unfortunately that all disappeared when the Suzuki T20 came out!

www.bsabantamracing.com and a face book site..

[125techdir]

Polinzei, cool looking stuff! :)

Below is my first part on the PLA made cylinder and casting it;
At first I wanted to buy a cylinder kit made by Stage6 or a Malossi speed 7T which all perform reasonably well.
However, in december 2014 I stumbled upon a guy on google who was casting an aluminium piece directly from his PLA printed 3D model (http://3dtopo.com/lostPLA/).
This made me interested in the subject and together with a metal foundry nearby where I live, we tried a sample ourselfs. It turned out that PLA will melt away 100%
without residues, so the method was indeed quite good to cast cylinders!

Together with a good friend we then formed the idea to start designing a cylinder ourself where we could work around the following:
- The original stud size is 56x56 with 7mm studs, this pattern is too small for a 47.6 bore cylinder to shape it correctly at the exhaust and b-port.
- Most aftermarket cylinders have the exhaust channel at a straight angle whereas we have tried to obtain the desired 20-25 degrees (if I recall it correctly).
- Cooling of most cylinders for a Derbi engine is asymmetric on one side of the exhaust channel.

First, I started making silicone molds of all sorts of cylinders I could get my hands on, a friend's 22 hp 50cc, an Aprilia RSA, a Honda 2007 a-kit, a KTM 125, etc..
(in the picture below are only a few of the silicones, I have enough to fill my desk :))
316263
With these molds, I went to a Fablab where they had a reasonable 3D scanner and I scanned the molds with an accuracy of (If I recall it correctly..) 0.1 mm.
Next, I sat together with my friend and given our appetite and enthusiasm to discover things ourselfs (in some people's eyes stubbornness), we decided to go with the Honda port lay-out as shown in the images.
316260316261316262
The Honda cylinder had the A-port its edge nearest to the B-port almost perpendicular to the bore and aimed at the other side. We decided to go with a more common direction of aiming the A-port further towards the C.
The axial angles are set to about 22 deg. for the A-port, 8 deg. for the B port and 50 deg. for the C-port.

After designing the cylinder in CAD, it was time to print it in PLA. As we had to remove / clean the white shell after casting, we decided to remove the "roof" above the exhaust port such that we could thoroughly clean the cylinder.
316265
Inherent to the FDM process used by our Ultimaker 2, overhangs and roofs larger than 50 or 60 degrees require support material to deposite the material during printing. Therefore, we had to design the cylinder in such a way that it was printable and all the support material was removable.

I'll elaborate on making the design printable and the actual casting next time, hopefully you guys like it!

cheers,

Peter

Hi, I have been down this route casting steel ports for a water cooled BSA 125 Bantam racer. If I may, could I say that it is worth considering the post casting issues of removing the ceramic from within the casting. We had a problem with small passages getting the shot blasting nozzle into the holes, it needs 'special tools' making to achieve clear passages especially if they are water cooling routes.
regards,
Roger (125techdir)

[WilDun]

www.bsabantamracing.com and a face book site..

Breezy, thanks for the links to the gearbox drawings etc. unfortunately they would have been much more useful to me over 50 years ago when I was struggling with a (so called) "close ratio" box which had a super high 1st gear and a second which was just slightly lower than top! (came in handy when there was a head wind of course).

[Arifidyan]

Wood everywhere - Love this method. (My 135cc piston block pattern)

[WilDun]

Wood everywhere - Love this method. (My 135cc piston block pattern)

You have plenty of wood in Indonesia, so it's a good idea to make good use of it. (while it's still there).

Have you made any moulds or poured aluminium yet? - I think that's a lot of fun too, even if I have about 50% failure rate (I don't talk too much about that of course!). - all going well, so keep it going.

[Flettner]

Wood everywhere - Love this method. (My 135cc piston block pattern)

Wood, yes cheap (free) and available, unlike money, It does grow on trees.
The Ryger style cylinder has been slow lately (work keeps getting in the way) but here is one of the water cores ( less the core prints ). I will be making a core box from this shape.
Also fitted the charging coils and fly wheel to the sleeve engine. I've decided I'm going to just get the sleeve engine running without the gearbox for the moment. A bit of a wast of time but but I just want to hear it run (or not). Also have several other cylinders lined up to test on this bottom end, one being a bastardisation of Frit's FOS. I'm glad I waited to finish the FOS as now there will some changes I've learn't from the Ryger saga.
By the way, if anyone out there has a YZ250 engine (and or gaerbox) for sale I'm interested. I think 2002 to 2007 model? This gearbox will be fitted to the sleeve engine.

[Arifidyan]

You have plenty of wood in Indonesia, so it's a good idea to make good use of it. (while it's still there).

Have you made any moulds or poured aluminium yet? - I think that's a lot of fun too, even if I have about 50% failure rate (I don't talk too much about that of course!). - all going well, so keep it going.

Yes, I've made the crankcase, no gearbox. Piston block is unfinished, I still improve its pattern. :D

[Arifidyan]

Wood, yes cheap (free) and available, unlike money, It does grow on trees.
The Ryger style cylinder has been slow lately (work keeps getting in the way) but here is one of the water cores ( less the core prints ). I will be making a core box from this shape.
Also fitted the charging coils and fly wheel to the sleeve engine. I've decided I'm going to just get the sleeve engine running without the gearbox for the moment. A bit of a wast of time but but I just want to hear it run (or not). Also have several other cylinders lined up to test on this bottom end, one being a bastardisation of Frit's FOS. I'm glad I waited to finish the FOS as now there will some changes I've learn't from the Ryger saga.
By the way, if anyone out there has a YZ250 engine (and or gaerbox) for sale I'm interested. I think 2002 to 2007 model? This gearbox will be fitted to the sleeve engine.

Yes, cheap & free. :D
Some good links :
http://www.kartbook.net/group/vintagehistorickarts?groupUrl=vintagehistorickarts&xg_source=activity&id=2879226%3AGroup%3A64169&page=199#comments

http://www.dea-engineering.com/?p=427


:scooter::scooter:

[WilDun]

Yes, I've made the crankcase, no gearbox. Piston block is unfinished, I still improve its pattern. :D

That's good, I see you are well on the way already, I need to keep going on my projects because you are getting way ahead of me!
Please keep us informed on how you are progressing.

[Flettner]

Screw in head made, just need the water cover. I have video of it being turned over as a compressor, air going in the reed and out the exhausts but I don't know how to load it? A whole new level (for me anyway). When I say video, I am talking about filming from my new phone.

[TZ350]

Screw in head made, just need the water cover. I have video of it being turned over as a compressor, air going in the reed and out the exhausts but I don't know how to load it? A whole new level (for me anyway). When I say video, I am talking about filming from my new phone.

Looking Good, load the video to YouTube then post a link here.

[Flettner]

Looking Good, load the video to YouTube then post a link here.

Ha Ha, I can't even get it out of the phone:laugh:
I'll ask one of the younger ones this evening, they will know how.

[husaberg]

Ha Ha, I can't even get it out of the phone:laugh:
I'll ask one of the younger ones this evening, they will know how.

You can down load the phone direct to the PC either though blue tooth or using the mini USB port.
you will need to turn on this function on your phone assuming your computer is less than 6 years old it should work.
You will need to then upload the video to youtube or similar.

[Flettner]

What? Anyway I found it on youtube.
https://youtu.be/of-c2dUnb3k

[breezy]

What? Anyway I found it on youtube.
https://youtu.be/of-c2dUnb3k

flettner, what kind of port timings have you gone with on the sleeve?

[Flettner]

flettner, what kind of port timings have you gone with on the sleeve?

What do you port a non supercharged sleeve valve? I went 192 exhaust and 130 inlet, see what happens? I could have out of phased the valve, say six degrees leed but I haven't on this first one. I'm more interested to see if it's going to seize.

[husaberg]

What do you port a non supercharged sleeve valve? I went 192 exhaust and 130 inlet, see what happens? I could have out of phased the valve, say six degrees leed but I haven't on this first one. I'm more interested to see if it's going to seize.

Seize, the moment it does, let us know. :shifty:
I think you could have gone even more conservative that's probably pretty racy timing as it has a fair bit of blowdown with the Sleeve set up anyway doesn't it Neil?

[Flettner]

The writing is on the wall (has been for a long time), I have to start to CAD draw stuff. Here is last nights hack. The water cover for the sleeve engine.
I've owned this Geometric Designs software for a while but it's been too difficult to turn it on. Seem to find somthing else to do rather than learn (age I guess). Also when I do start to use it, it gets so frustrating I just go and make the part without a drawing. For a while there I thought what a wast of money but now I see it's usefullness. I'll have a go at 3D cutting the part out on the CNC this weekend.

[WilDun]

The writing is on the wall (has been for a long time), I have to start to CAD draw stuff.
For a while there I thought what a wast of money but now I see it's usefullness. I'll have a go at 3D cutting the part out on the CNC this weekend.

Yes, I guess it's inevitable and like everything else we are content with what we have and don't feel like starting again, but seeing as you have good CNC equipment I think it's a very good idea to use it in conjunction with your draughting program - coreboxes and patterns made 10 times more quickly than previously! (and it'll be great for when you aren't able to throw a leg over a bike anymore).

I have only got an old engraving machine which I bought when I was laid up, in case I wasn't able to work again but that's not really much use for anything else.

Like you, I have a 3D drawing program, it's probably more basic than your's (but still quite good) - the 3D part I haven't really caught up with yet (maybe never will).

It's probably too late for me to learn anyway! :laugh:

[Flettner]

Yes, I guess it's inevitable and like everything else we are content with what we have and don't feel like starting again, but seeing as you have good CNC equipment I think it's a very good idea to use it in conjunction with your draughting program - coreboxes and patterns made 10 times more quickly than previously! (and it'll be great for when you aren't able to throw a leg over a bike anymore).

I have only got an old engraving machine which I bought when I was laid up, in case I wasn't able to work again but that's not really much use for anything else.

Like you, I have a 3D drawing program, it's probably more basic than your's (but still quite good) - the 3D part I haven't really caught up with yet (maybe never will).

It's probably too late for me to learn anyway! :laugh:

Never to late.

See here the inner part 3D machined out, oring even fits. Out side is more tricky, I'll have a hack at that tomorrow.

[Sketchy_Racer]

Never to late.

See here the inner part 3D machined out, oring even fits. Out side is more tricky, I'll have a hack at that tomorrow.

What CAM software are you running Flettner?

[Flettner]

What CAM software are you running Flettner?

Gibbs CAM, I mostly just use the two and a half D, although it is full 3D capable. My worker, Phillip is real good at the 3D stuff, he is teaching me. :rolleyes:

[WilDun]

Gibbs CAM, I mostly just use the two and a half D, although it is full 3D capable. My worker, Phillip is real good at the 3D stuff, he is teaching me. :rolleyes:

Guess you'll eventually be trying 3D printing for cores and patterns, seeing as you are already more or less there? (except for a printer of course).

[F5 Dave]

You can hire time on those. The resin cost can be significant depending on what they use. Vs what you need.

[Flettner]

Other side done, now to draw the reed inlet manifold.

[Flettner]

Guess you'll eventually be trying 3D printing for cores and patterns, seeing as you are already more or less there? (except for a printer of course).
No I won't be using a 3D printer, I need the core boxes and dies made from steel ultimately. The CNC is good for that, it's just my lack of
3D drawing experience, only I can fix that problem. I always seem to find ways around having to draw the item up in CAD.

[WilDun]

No I won't be using a 3D printer, I need the core boxes and dies made from steel ultimately. The CNC is good for that, it's just my lack of
3D drawing experience, only I can fix that problem. I always seem to find ways around having to draw the item up in CAD.

How long till you fire her up?

So I guess you'll be aiming to use resin/coresand exclusively? - wouldn't cast iron be easier to machine and tidy up (smooth)? also easier to remove cores etc. because of graphite in it, would the graphite affect the ally? - guess it is a little messy though.

It's still good to be able to draw up a sketch with a pencil (and rubber) - no degree required to operate it! - I reckon so anyway.

[Flettner]

How long till you fire her up?

So I guess you'll be aiming to use resin/coresand exclusively? - wouldn't cast iron be easier to machine and tidy up (smooth)? also easier to remove cores etc. because of graphite in it, would the graphite affect the ally? - guess it is a little messy though.

It's still good to be able to draw up a sketch with a pencil (and rubber) - no degree required to operate it! - I reckon so anyway.

I could "fire her up" this aftenoon but I'm bent on using the 3D drawing and CNC to make the rest of the parts (the inlet manifold) so when I have the part drawn and machined, then we will start it up.
Cast iron would be quite suitable, grahpite is not a problem as I coat the die surfaces with carbon anyway (via the acceteleen torch). I have no problem with 3D printers but when I have this CNC availble why wouldn't I use it? Plus it's more accurate anyway.
I did show off old school pattern making on this thread to show you don't need all this fancy expensive hi tec stuff (CNC / 3D printers etc), if you only have basic hand tools, some wood and bondi / glue (and beads) you can make your own cylinders and other stuff.

[WilDun]

I could "fire her up" this aftenoon but I'm bent on using the 3D drawing and CNC to make the rest of the parts (the inlet manifold) so when I have the part drawn and machined, then we will start it up.

I did show off old school pattern making on this thread to show you don't need all this fancy expensive hi tec stuff (CNC / 3D printers etc), if you only have basic hand tools, some wood and bondi / glue (and beads)

That's good, :niceone:

[Flettner]

Been a bit busy anyway today, off to Red Woods trail ride. Grand daughter showing Grandad how it's done, PW styles. Moments after this picture we ended up in the blackberries, opps. After a few tears (mine) we were back out riding, this is what life is all about:yes:

[Flettner]

I could "fire her up" this aftenoon but I'm bent on using the 3D drawing and CNC to make the rest of the parts (the inlet manifold) so when I have the part drawn and machined, then we will start it up.

It's a battle of wills, I give in, I've spent all afternoon trying to get the computer to insert a plane ( to draw on ) at an angle, can't be done. Tutorial seems to assume you already know some stuff.
I think I'll just go out to the shed and make one (manifold) Computers can be soooo useless sometimes. Trouble is you can miss the smallest detail and nothing will work, but it won't tell you what that detail might be. Perhaps I'm just too old (and grumpy).

[Lightbulb]

Parallel planes are easy, just offset. Inclined planes usually require a line drawn on an adjacent plane at the incline required, then you effectively look down on that line and create the plane on the line you created as being the centre of axis if that makes sense. If it is like a pipe, you make a spline or curved line that becomes the centre of the path. Then draw the profile at one or either end if they are different, and then pick the line for the shape to go through. Then you have either a solid or you can make it the inner or outer for a shell shape.
Neil

[Flettner]

Parallel planes are easy, just offset. Inclined planes usually require a line drawn on an adjacent plane at the incline required, then you effectively look down on that line and create the plane on the line you created as being the centre of axis if that makes sense. If it is like a pipe, you make a spline or curved line that becomes the centre of the path. Then draw the profile at one or either end if they are different, and then pick the line for the shape to go through. Then you have either a solid or you can make it the inner or outer for a shell shape.
Neil

Yes I've got that, I can easily offset a plane but for some reason with an angled plane, It asks for angles, I set angles but it won't let me apply. Clearly there is some other detail missing, but it's a guessing game and I told it "you win". :rolleyes:
One of my customers uses the same program, he is very good at it so I will consult him tomorrow. This computer may have won the battle but it won't win the war, I WILL win!

Angle plane inserted !! I Beat it.

[Sketchy_Racer]

Ahh, 3D modeling, the cause and solution to most engineering problems ;)

Did you have to draw a line on the first plane to give yourself a point of rotation for the new plane at an angle?

[Ocean1]

Yes I've got that, I can easily offset a plane but for some reason with an angled plane, It asks for angles, I set angles but it won't let me apply. Clearly there is some other detail missing, but it's a guessing game and I told it "you win". :rolleyes:
One of my customers uses the same program, he is very good at it so I will consult him tomorrow. This computer may have won the battle but it won't win the war, I WILL win!

Angle plane inserted !! I Beat it.

What are you using? Solid Works?

[Flettner]

It's Geomagic Design, was Alibre. I can't afford / justify Solid works and I see Alibre around in a few engineering / design workshops.
It is easy to use, but for this angled plane stuff. I would love to say I sorted it out myself but that would be untrue, I used the young ones here (computer savy) to help me out. It does help to understand what the program is trying to tell you, it uses words I don't even know the meaning of. Any way good to go now. I find there is nothing in this world like a computer to piss you off, thats why I try to avoid turning it on:facepalm:
Oddly enough I have no such problem with Gibbs (two and a half D) I belive it must have been written by an shop floor engineer:laugh:

[Frits Overmars]

...there is nothing in this world like a computer to piss you off... Oddly enough I have no such problem with Gibbs (two and a half D) I believe it must have been written by an shop floor engineerAny program gets better when the person who wrote it starts using it himself.

[Peiter]

In my experience, learning to work with 3D CAD software just takes time and practice practice practice :).

It took me about 2 to 3 full days before I understood how I should accurately build the shapes of transfers in Siemens NX. Lots of planes, intermediate planes, splines, sketches, integrated sketches, etc. further I finally mastered the trick. Then, drawing the cylinder and a waterjacket with equal wall thickness everywhere was the same kind of drama the first time :no:

[WilDun]

Any program gets better when the person who wrote it starts using it himself.

That doesn't happen too often!
Politicians and bean counters, using computer 'wizz kids' will always rule the roost, all living in a world of fantasy - not engineers who actually live the real world.

Having said all that, I think Peiter is right!

[Flettner]

In my experience, learning to work with 3D CAD software just takes time and practice practice practice :).

It took me about 2 to 3 full days before I understood how I should accurately build the shapes of transfers in Siemens NX. Lots of planes, intermediate planes, splines, sketches, integrated sketches, etc. further I finally mastered the trick. Then, drawing the cylinder and a waterjacket with equal wall thickness everywhere was the same kind of drama the first time :no:

Yes you are right, I just have to get over myself and practice practice.

[Ocean1]

It's Geomagic Design, was Alibre. I can't afford / justify Solid works

Similar interface then. I learned to use Rhino, it had some features then that made it good to work with a big CMM I was using. I've learned some solid works since, and some NX11....
Rhino tends to want a different approach to modelling, and watching others learning I've noticed that those who pick up SW type front ends reasonably easily don't "get" Rhino, and vice versa.

https://www.rhino3d.com/download

It's free, for 90 days. Also free to students.

[husaberg]

Neil I started shaping the transfers on my pattern model and I noticed the RSW has a huge negative draft on one side of the transfers.
So the question is did they machine this side out afterwards (I don't think they did)
Or did do you think they make it in pieces ie multiple patterns in resin glued together?

[Flettner]

Neil I started shaping the transfers on my pattern model and I noticed the RSW has a huge negative draft on one side of the transfers.
So the question is did they machine this side out afterwards (I don't think they did)
Or did do you think they make it in pieces ie multiple patterns in resin glued together?

Ha, with my new found skills I'd 3D machine it:bleh:
No probably done with a core print or just made that part of the sand mold come appart separatly, slide the sand part horrizontal first before the pattern comes out vertical.

[monkeyfumi]

That doesn't happen too often!
Politicians and bean counters, using computer 'wizz kids' will always rule the roost, all living in a world of fantasy - not engineers who actually live the real world.

Having said all that, I think Peiter is right!

Most engineers I've met, live a long way away from "the real world"

[WilDun]

Most engineers I've met, live a long way away from "the real world"

Unfortunately today's 'real world' is a world of fantasy and as you'd expect, engineers will live a long way from there! I should have said the "sane world"

:rolleyes:

[Flettner]

Unfortunately today's 'real world' is a world of fantasy and as you'd expect, engineers will live a long way from there! I should have said the "sane world"

:rolleyes:

Yessiree, fantasy and fairy dust, thats where I live:pinch:

I don't know that I will live long enough to finish drawing this angled manifold, all well and good drawing on the angled plane but then try to tie it back to the rest of the dam drawing :facepalm: O well, off to ask someone again.
I guess it's just a matter of knowing when to cut your losses (time) and just make it.

[WilDun]

I guess it's just a matter of knowing when to cut your losses (time) and just make it.

Back to the dull old world of sanity now - I'm hoping to make a Co2 mould (just a bold experiment into the wonderful world of metal casting, where many have ventured before)
Should I 'rap' the pattern half before the Co2 is applied, in order to make it more easily removed when it has been hardened? - guess it would be silly to remove the pattern half while the sand is in in the soft state - or would it?

[Flettner]

Back to the dull old world of sanity now - I'm hoping to make a Co2 mould (just a bold experiment into the wonderful world of metal casting, where many have ventured before)
Should I 'rap' the pattern half before the Co2 is applied, in order to make it more easily removed when it has been hardened? - guess it would be silly to remove the pattern half while the sand is in in the soft state - or would it?

Your pattern should be so smooth as to just be pulled straight out. HARDEN the sand first, a light tap wont hurt. I cover the pattern in graphite powder first to make it real slippery. Rub it in to the pattern surface with your fingers. Sometimes you have to use some threaded rod and a slide hammer arrangement to knock the pattern free. The sand should go resonably hard if mixed well.

[Frits Overmars]

I don't know that I will live long enough to finish drawing this angled manifold....I know the feeling Neil. Sometimes when I look back over a couple of weeks or even months it's like I didn't accomplish anything at all.
But then, when I look back over a year, it wasn't so bad.

[Flettner]

I know the feeling Neil. Sometimes when I look back over a couple of weeks or even months it's like I didn't accomplish anything at all.
But then, when I look back over a year, it wasn't so bad.

My problem, one of many I guess, is because I can just make stuff, I do. For a long time now I've concidered drawing things up in CAD a wast of time. BAD mind set!! But that is just how it's been, I arrange everything in my head and work from there. Because I've put off this CAD process for so long it's real painfull now. Still as you say look back over a year and it won't be so bad, I hope.

I've just managed to loft a hole through the manifold, finaly, seem you can't just go leaving spare lines in the drawing, computer doesn't like it.

[Michael Moore]

I just finished watching this 115 minute video on the casting of a replica of the Wright Brothers Model B aeroengine crankcase. It was shot by the folks at Model Engine Builder Magazine at a foundry here in the San Francisco Bay area.

https://www.youtube.com/watch?v=6kcUJeg4Ifk

This is an amateur video shot in a foundry where work is going on. I think 10-15 minutes could probably have been edited out, and it isn't uncommon for dialog to be drowned out by a compressor or people chatting nearby. It was not scripted but rather just follows along as the process progressed. But there is a lot of detail on the process that is shown, and I found it very interesting.

There's discussion and display of patterns and core boxes through creation of the mold, melting the iron, pouring the casting and the demolding of the finished casting.

Unfortunately, the boss didn't answer the "how long did it take to design and make all the patterns and core boxes" question, as I would have been interested to hear the answer.


I had the first foundry day at my house a week ago and thought I'd share some info since "can I use a pottery kiln to melt metal?" seems to be a not uncommon question for DIY foundry fun.

I bought off of Craigs List a Skutt model 818-240 pottery kiln, 240v single phase, 21.7A, 5200W. Internal dimensions are about 17" ID x 17" deep. It has a manual "kiln sitter" power control, but for melting it runs at full power all the time. The kiln looked pretty much unused, and I paid about $300 for it. I run it on a 50A circuit that normally feeds my air compressor.

On Friday I did a test run on the empty kiln and monitored the temperature with a K-type thermocouple and thermometer display. I had the kiln control dials set on 3 of 10 to start but after 6 minutes I realized there was no reason to not run the thing on 10, so I changed at that time.

Starting temperature was 71F. The rate of rise at the lower setting was about 15F/minute, and after changing to full power that jumped to 57F/minute, so I wasted a few minutes with the lower setting.

I let it run for 60 minutes, checking every 5 minutes (or so). The rate of rise drops as the temp goes up, starting around 57F/min and ending at 11-12F/minute. The final temp was 1568F, for a 1500F degree increase over 60 minutes.

The next day my friend Jeff came over with some of our supplies - scrap aluminum, Petrobond sand, flasks, silicon carbide crucible (rated for 10 pounds of aluminum), tongs etc.

The crucible weighs 11.6 lbf when empty. The refractory plinth it sat on in the kiln was 4.4 lbf, and we put 5.5 lbf of aluminum in it to start.

The rate of temperature rise with that 21.5 lbf added was significantly reduced compared to the empty kiln. Starting at 68F ambient and at full power it took 91 minutes to reach 1400F which showed a partial melt of the metal. The temp dropped to 1360F from that brief look but recovered quickly. At 100 minutes it was 1450F and the melt temperature was 1280F. We let it go to 111 minutes at which time the kiln temp was 1508F and the melt was at 1380F. I then removed the crucible and poured 4 flasks totaling 2 lbf. The lid was left open (I should have shut it) and at 116 minutes the temp in the kiln was showing 827F. About 6 lbf of scrap was added to the heel in the crucible making for about 9 lbf of metal. That was poured out into ingots at 158 minutes. The kiln temp was 1447F and melt temp was 1270F and parts of the melt seemed a bit slushy. But I didn't feel like waiting another 10 minutes to get the melt hotter since we weren't going to pour any more flasks.

I've attached a graph that Jeff generated showing the relative temperature curves for the empty and filled kiln. The equations shown are for the two curves. Jeff's a scientist so he does that thing as a standard practice. The curves were plenty for me. :)

The molds were of that 4" medallion for Jeff's annual ride in the Sierras that I showed after his first foundry day a couple months ago. This time we tried different gating with the sprue off to the side instead of coming directly into the back of the part, and also varied putting the pattern in the drag and the cope, detailed side down or up, to see if we could learn anything from that.

Pros & cons for a powerful propane furnace (Jeff's) vs the electric furnace:

The propane furnace runs a lot hotter and has a melt ready in about 15 minutes with the crucible glowing white hot. We think that the blower/fuel can be turned down from that setting, as at a good melt temperature the crucible came out of the electric kiln with only a slight reddish glow (I couldn't see it, Jeff did).

The melt seemed more turbulent in the fuel furnace. In the kiln it just sat there and there wasn't any movement breaking the oxide layer or dragging oxides down into the melt. That may improve in the fuel furnace by turning the fuel/air down, and even if that doubles the melt time it will still be much faster than the electric kiln.

Electric is quiet and discreet. There's no roaring sound or flames shooting out of it to attract the neighbors' attention. Electric can be run inside, and there's no need to worry if the branches of a nearby tree are far enough away to not be in danger of igniting.

Electric may be less expensive to operate and own. A residential kW/hour appears to be about $0.23 here in San Francisco. The kiln is rated at 5.2 kW, but even if rounded off at $0.25 and up to 6 kW, that's US$1.50/hour running costs which seems pretty reasonable to me. We don't have any running costs for the propane furnace, but Jeff mentioned that he had the big cylinder available because small ones wouldn't even keep up with his big BBQ much less the furnace. Used pottery/glass kilns seem to be pretty common on the SF Bay Area Craig's list, and if you don't need fancy kiln sitting controls you may be able to pick up something at a very reasonable price. The 10 lbf capacity crucible is about 7.5" OD x 8" tall, so the 17x17 inside dimensions on this kiln are very roomy and a smaller kiln would have plenty of space inside.

Electric may be more convenient. No big tanks have to be carted around to get refilled nor does storage space have to include the tank(s) as well as the furnace. Jeff's propane tank was getting pretty frosty after it had run for a while which might change the available pressure. The electricity keeps running as long as needed and the supply doesn't vary. Fuel and air had to be fiddled with now and then on the propane furnace.

This time, since it was at my house, I did all the handling of the furnace/melt. I wore my hot suit, foundry gloves and electronic TIG helmet, and there were no accidents other than sitting the hot crucible down near the temperature reader for the thermocouples, resulting in a slightly warped plastic case on the gauge. :)

Now we need to get some patterns made for real parts that will use the A356 ingots and filters in the gate before the part to trap oxides. Jeff's been working on the air-cooled cylinder head pattern for his 400cc Kawasaki triple, and that is looking very nice. It may be ready to pour in a week or so.

cheers,
Michael

[WilDun]

I just finished watching this 115 minute video on the casting of a replica of the Wright Brothers Model B aeroengine crankcase. It was shot by the folks at Model Engine Builder Magazine at a foundry here in the San Francisco Bay area.
cheers,
Michael

Excellent video Michael, got a lot of tips from that one! I am just about to try the Sodium Silicate/Co2 method, thank you for the link. They need to oil the bearing on that muller though!