The Bucket Foundry

[speedpro]

For Flettner

https://www.youtube.com/watch?v=ESamdF_d4b4

[lohring]

An even more fun version: https://www.youtube.com/watch?v=SL1uwRtqPWE

Lohring Miller

[Flettner]

https://youtube.com/shorts/HGg_mI9OKjI?feature=share

[Frits Overmars]

https://youtube.com/shorts/HGg_mI9OKjI?feature=share...........:clap:

[lohring]

https://youtube.com/shorts/HGg_mI9OKjI?feature=share

The most fun version.

Lohring Miller

[husaberg]

Cool belt tensioner doubles as a magneto.

[GerbilGronk]

You need a bigger drill......:

[Flettner]

More parts

[F5 Dave]

So has anyone heard from Mike Stien who started this thread?

[husaberg]

So has anyone heard from Mike Stien who started this thread?

pm chatted with him a few weeks ago.

[Flettner]

Sorry Dave if this isnt up to your minimim standard of intetest but others may be intetested, no more rockets.
A 125cc air cooled cylinder, for Bucket Vinduro, rules state air cooled. Here CNCed up a wee die to pour resin fins for a pattern. It will bolt to my universal rotary disc valve bottom end, the one being used for the 175cc uniflow at the moment. 52 bore, 58 stroke, eye ports, 5mm exhaust dam, 34mm carburetor, petrol. Single rotary disc sliding gib. Cast in LM13, Nikasil bore.

[Flettner]

I might have to create some artificial gravity to fill the die properly. Micro drive to control that gravity.

[F5 Dave]

Well I've just been watching Shaun the Sheep with the kids, so kinda on track for rocket Aardmen stuff.

This should be a hoot. How will you keep the aircooled fins attached? Complicated.

[Flettner]

Left one just gravity, air got trapped in the extremities and didnt fill the die properly.
Right one spin cast, clearly much more satisfactory.

[husaberg]

Left one just gravity, air got trapped in the extremities and didnt fill the die properly.
Right one spin cast, clearly much more satisfactory.

how fast was it spinning.

[Flettner]

how fast was it spinning.

Estimating 500 ish revs.

[WilDun]

This looks very interesting - same bore/stroke as the good old BSA Bantam etc! - the new bucket standard?

[Flettner]

No more casting resin until after Christmas, bugger.

[ken seeber]

Nothing like a bit of spin.

351602

Kart disc brake rotors we make. 200 in dia * 12 thick. Weigh around 420 gm compared to 1200 for a CI equivalent. Same material as our pistons. Ductile iron dies.

Top left is without spin, right is with 180 rpm spin, partially machined and lower middle finished.

[husaberg]

Nothing like a bit of spin.

351602

Kart disc brake rotors we make. 200 in dia * 12 thick. Weigh around 420 gm compared to 1200 for a CI equivalent. Same material as our pistons. Ductile iron dies.

Top left is without spin, right is with 180 rpm spin, partially machined and lower middle finished.

So what are they coated with Ken. or is the Si content and kart drivers wallet enough?
I know that plenty of GP bikes in the early 80 used zanzani (not sure spelling)rotors as did MV before then.
I think they were plasma coated with always Fe it always sounded to me like dude with spraying a gun like the one used to build up a crank.

[Flettner]

Wheels won an Ohakea GP using an aluminum disc, plasma sprayed. Oh.... and centre hub steering. Kawasaki 100 with 19HP I believe, no mean feat.

[F5 Dave]

Was it plasma sprayed? I've seen a few done with the right ally and organic pads.

[ken seeber]

So what are they coated with Ken. or is the Si content and kart drivers wallet enough?
I know that plenty of GP bikes in the early 80 used zanzani (not sure spelling)rotors as did MV before then.
I think they were plasma coated with always Fe it always sounded to me like dude with spraying a gun like the one used to build up a crank.

Whosarr, not coated. As it happened we were casting these today, so attached are some pics. Some say the beer barrel is appropriate.

351604351605351606351607

The 4 bobweights provide a centrifugal clamping force, important to not have hot metal spinning/leaking out at waist height. The level of escape is also withing the barrel.

[Flettner]

Whosarr, not coated. As it happened we were casting these today, so attached are some pics. Some say the beer barrel is appropriate.

351604351605351606351607

The 4 bobweights provide a centrifugal clamping force, important to not have hot metal spinning/leaking out at waist height. The level of escape is also withing the barrel.

Nice setup.

[Flettner]

Makes the supercharger look small.
Sitting on the doorstep this evening.
Lots of work to trim this down to a less sizable lump. I should weigh it as is, before and after as it were.
It was almost free thankfully.

[F5 Dave]

I hope you're going to put a young fella on that as the crash test dummy rather than risk your own good self.

[WilDun]

Makes the supercharger look small.
Sitting on the doorstep this evening.
Lots of work to trim this down to a less sizable lump. I should weigh it as is, before and after as it were.
It was almost free thankfully.

Neil, I'm sure it's probably going to be an experiment of course, but what is your aim? - (bikes or aircraft?) - will you be fitting a balancer as well? (assuming it doesn't have one or two of those!).

[Flettner]

For Vinduro use, new class. I want to enter something..... unexpected but within the rules. This is it.
Im having trouble finding someone to grind the bigend journals at 15mm wide. Ive ordered a new wheel for my cylindrical grinder, Ill grind it myself, the centres are still in place thankfully.

[husaberg]

For Vinduro use, new class. I want to enter something..... unexpected but within the rules. This is it.
Im having trouble finding someone to grind the bigend journals at 15mm wide. Ive ordered a new wheel for my cylindrical grinder, Ill grind it myself, the centres are still in place thankfully.

I think that was what used to stop the 250 four engines
Grumph will confirm
i think they have many size shells but not for regrinds.

[Flettner]

A new grinding wheel will just work if I thin it down to 14.5mm. At 305 dia it is just big enough to reach in.

[Grumph]

A new grinding wheel will just work if I thin it down to 14.5mm. At 305 dia it is just big enough to reach in.


Generous radii in the corners please. And take the edges off the oil holes where they break out onto the shaft surface. The rpm and load you're going to give it means taking great care prepping the crank and rods. Going to nitride it ?

[Flettner]

Yes, it has to be nitrided. Im copying the FZR bigend journals, including the radius. Wayne (Blackwood Yamaha) is getting me some new bigend shells.

[Grumph]

Yes, it has to be nitrided. Im copying the FZR bigend journals, including the radius. Wayne (Blackwood Yamaha) is getting me some new bigend shells.

If he suceeds, let us know where he found them please.

[husaberg]

If he suceeds, let us know where he found them please.

Plenty for sale in China but from what i understand you need to buy all sizes and selectively fit.
if the bearing metal is as soft as they fasteners and have as much lead as they kids toys paint, they should do well in service.

[Gradella23]

Hello guys, i'm new here. My name is Andrea and i'm from Florence, Italy.
I'm trying to cast my first 50cc cylinder, which i designed from 0, mainly thanks to all the knowledge i got here and on pitlane.
I'm looking for advice about core boxes design.
Since i'm too poor to pay someone to study and manifacture all the necessary stuff for casting, i'm trying to model and create the core boxes by myself via 3d printing.

I've already tried some prints and coated them with a special filler, and the results were good: optimal roughness, perfect alignment and coupling.

The problem is that since this is my first try with castings, i'm experiencing some difficulties at "reverse thinking" to obtain the right planes and angles and all.
I'm a mechanical designer with skills on Creo 7, so the software part is not too much of a problem (even if i needed to learn some surfaces features i wasn't used to).
I thought that maybe an expert eye can solve in 5 minutes what i'd need 5 days to understand.
-First of all: i know that i usually need a min 2-3° draft angle to extract the cores, but can i just ignore that where i don't need a strict dimensional control? For example on the outside shell or in some liquid pattern surfaces? i don't care if the sand rubs on the walls a little. The local foundry man said that he's not using my boxes if they're at 90°...
-there are some surfaces, especially those in the ducts, than i can't reshape to avoid a negative draft: how can i design the core boxes in these cases? (The green core)
-any suggestion on how to divide the box for the fuchsia core? if i divide it in two halves on the vertical plane i always have negative angles (see the yellow and orange models)
thanks for your attention
Andrea

[lohring]

Attached is my method for creating a 3D model of the various passages in a 26 cc race engine. I use Fusion 360, but other 3D modeling programs should be similar. I model the passages as solids then subtract them from the solid shape of the engine. That method should also work for creating core boxes.

Lohring Miller

352086

[Flettner]

Not exactly sure what you are asking but if I understand the question, I make my transfer core boxs like this. Split edge to edge, this way the transfer cores can have straight sides, no taper and yet still pop out cleanly and easily, with no sticking.

[Gradella23]

Attached is my method for creating a 3D model of the various passages in a 26 cc race engine. I use Fusion 360, but other 3D modeling programs should be similar. I model the passages as solids then subtract them from the solid shape of the engine. That method should also work for creating core boxes.

Lohring Miller

352086

thanks Lohring, it's interesting. My method is very similar, i also use surfaces blends to control shapes. And of course i subtract cores from a solid, my main concern is how to divide properly the boxes to avoid negative drafts.


Not exactly sure what you are asking but if I understand the question, I make my transfer core boxs like this. Split edge to edge, this way the transfer cores can have straight sides, no taper and yet still pop out cleanly and easily, with no sticking.

mm so the only way i have to make the c transfer pop out is to create a single core box for the duct without having it already tied to the central core, right?

anyway, at the moment i found a fairly cheap alternative in voxeljet 3d printed sand cores: the full core with tranfers, cooling core and exhaust duct comes at 100€ for the single piece, and 26€ each if i buy 5. I'm going to try this for the prototype and then evaluate if this tecnology is good enough from a tolerances and roughness perspective.
thanks for your help guys! will post update if you're interested.

[Flettner]

These cylinders cost fu%^^k all, just some bondifill, wood from the wood shed, plastic beads, sand and some molten metal. Also a wee bit of time. Now I can make as many as I want with just a bit of sand consumables.
Sand printing is wonderful, but that cost is each time, can add up to be expensive once you want more and more cylinders with detailed changes.
Transfers are keyed and glued in place.

[Gradella23]

These cylinders cost fu%^^k all, just some bondifill, wood from the wood shed, plastic beads, sand and some molten metal. Also a wee bit of time. Now I can make as many as I want with just a bit of sand consumables.
Sand printing is wonderful, but that cost is each time, can add up to be expensive once you want more and more cylinders with detailed changes.
Transfers are keyed and glued in place.

no doubt, that remains the absolute best. I plan to continue the development of traditional core boxes once i got a taste of what I'm doing.
After all if you consider that I don't have the space and the tools to build a proper home foundry, it sounds nice to me to pay a batch of 10 full cores 19€ a piece! (even with 10 different adjustments if needed, that doesen't affect the print cost). I think the local foundries would charge a similar if not bigger price to form sand cores from my own boxes.
I've already changed the outiside shell core to add 2° drafts since the outer boxes will be still done the old way:

don't pay attention to the channel and sprues, it's just an hypotesis without too much thinking.

[Gradella23]

Hello everyone,
I received a nice little gift from Voxeljet at the office today :2thumbsup

[Brett S]

Nice, I'm pretty sure on facebook i saw Ian Harrison of Viper Racing use that technique of joining the water core to the rest of the printed cores as well.
Not sure if just for prototype cylinders or production.
Is there enough room to fit a cooling channel between the transfer and the bore?
How much did they cost if you don't mind me asking?

[Gradella23]

Nice, I'm pretty sure on facebook i saw Ian Harrison of Viper Racing use that technique of joining the water core to the rest of the printed cores as well.
Not sure if just for prototype cylinders or production.
Is there enough room to fit a cooling channel between the transfer and the bore?
How much did they cost if you don't mind me asking?

i paid 85€ excl. vat, but the same core would cost 19€+vat if i buy 10 of them and 25€ if i buy 5.
Obviusly the size plays a major role here, this part is 130x105x87mm.

the cooling channel on the inside of the transfer will be the next improvement for sure, i was only afraid about some cracking cause the biggest channel i can fit there is barely 5mm thick.
the next time i'll try that, i already have the updated model, and i'd also like to try a bridged exhaust.
but first of all i need to have the prototype casted.

[lodgernz]

Anyone know where I can buy some green casting sand in Wellington?

[Flettner]

Where is your nearest foundry? Fielding?

[lodgernz]

Where is your nearest foundry? Fielding?

Yes, Feilding or Palmy, but I was hoping to save a four hour trip. Must be someone in Welly?

[F5 Dave]

I can make some yellow sand. Might smell a bit when heated up.

I remember going to a foundry next to JJF when I was visiting them. Back in Seaview. Long gone by now. Erm, Neeles rings a vauge bell.

[ken seeber]

Here's a pretty cool process...with old mate "2 stroke Stuffing"

Looks like an ExOne sand printer is beyond the budget for a tinkerer. Neil, you could use one...:niceone:

https://www.youtube.com/watch?v=CxiHRGwTKec

[Peter1962]

Not sure if these youtube video's concerning casting for Kreidler already passed here on the thread ?
https://www.youtube.com/watch?v=_zO27SWRMco