The Bucket Foundry

[ken seeber]

SLIDER UPDATE.

Finally got the thing running on the dyno frame. No load being applied by dyno, still got some software and hardware issues to be resolved. Main purpose was to see what falls off and even if it still works.
Have a look at this: https://youtu.be/PaYYIfLnHkA I’m not the young bloke, but you probably knew that !!

Not too much to say other than it makes some noise (apparently it could be heard over in kiwiland !!). Seems to zing with a bit of throttle, but then so does any 2 stroke really. Felt like 71 hp though.

Obviously the next thing is getting the dyno sussed.

[breezy]

SLIDER UPDATE.

Finally got the thing running on the dyno frame. No load being applied by dyno, still got some software and hardware issues to be resolved. Main purpose was to see what falls off and even if it still works.
Have a look at this: https://youtu.be/PaYYIfLnHkA I’m not the young bloke, but you probably knew that !!

Not too much to say other than it makes some noise (apparently it could be heard over in kiwiland !!). Seems to zing with a bit of throttle, but then so does any 2 stroke really. Felt like 71 hp though.

Obviously the next thing is getting the dyno sussed.

Nice one Ken ( didnt hear it over here but sounded like at least 71.5hp on the video)

[ken seeber]

Busy rebuilding the calipers for my dyno. I'm adding a "bit" more grunt to the inertia drum I have. Hopefully I can then tune 2s a bit better.

Attachment 330887

Wallace, was thinking about your dyno. You refer to it as an inertia dyno, and it could be that you are using it for that function, but to me the actual “flywheel mass” looks relatively small, probably resulting in it needing to be spun at high speeds, hence the concern for your safety and you do seem like a really nice bloke.

So, with all that absorption capability and given the fact that you want to sort out an engine, to me it seems you have the need and most of the ingredients for a steady state dyno. Most, but not all, cos you don’t appear to have a way to measure load. One thought is to use your absorber exactly as is, but add a transmission dynamometer arrangement like this.



Relatively easily done with chain, eg karting #219 chain and idlers using kart engine clutch style needle rollered sprockets G (eg Rotax Max) and a large rear axle sprocket as the big idler and a smaller axle sprocket as the input sprocket for your absorber. You’ll have to measure the torque of the arm to get the engine torque and do a simple calc to get power. Typical teeth numbers might be engine sprocket J 12T, idler H 88T, small idlers G 14T and dyno input sprocket K 60T. Hope that all makes sense.

Beauty of this is that you can use anything as the absorber: friction brakes as you are, a propeller, water pump, eddy current absorber, a generator etc.

[Grumph]

Not in any way answering for Wallace...just clarifying. He's got an inertial dyno which is actually quite good. I've had a bike on it once. Works fine.

What he's trying for as I understand it, is a way to hold a steady load to try and sort fuelling and other issues....

I have pointed out the ease of putting a load cell on a reaction arm to turn it into a classic reaction dyno with adjustable load.
He's aware of how fast the load has to be adjusted too.

Personally, I find it easiest to take the bike for a blat up the road to sort carburation - but I live a lot further out of town than he does.

[Kickaha]

Too much braking may result in the whole dyno stand somersaulting.

So long as he gets it on video then I'm ok with that

[marsheng]

I'm adding it to my inertia dyno.


It is a 700 kg ex steam drum.

As Grumph said, I want to hold a steady load.

There are 3 ways I can use this configuration,

1 Obviously inertia
2 Steady
3 a combination of both.

3 is important as I don't like spinning he drum to +160kph, especially when it originally only went to 15 kph. It has been dynamically balanced and is vibration free. I am hoping to do a combination of inertia and brake. Anything over 50hp spins the drum to fast for my liking.

My guess at this point is that the friction is linear. Ie at x pressure and y rpm, the power absorbed is k. At 2y rpm the power would be 2k.

I have purchased a electronic trailer brake unit which I will interface to the system getting feedback from a load cell to make it all work !!!

Fritz, I will take the rapid braking into consideration.

[marsheng]

We have drifted a long way from foundry stuff, but unless we can accurately measure our foundry results on the dyno, it really is guess work all along.

So with my modified Maico, I need to make sure the the timing and fuel are all correct with my current motor before I start making new cylinders so I have a valid starting point.

Cheers Wallace.

[ken seeber]

Cool. I thought that the disks were the inertia dyno.

As you were then....

[Flettner]

Back to casting then. These two gear reduction units are heading off to South Africa today. Housings not cast by me though, done by Skellerns in Auckland. They do a pretty good job but are expensive. These housings are LM 25 heat treated to T6, nice to machine. These units bolt to EJ Subaru engines for use in Aviation, they give the propeller something better to hold on to other than the crankshaft, which is not suitable. Also uses a gear reduction to reduce the RPM and gain torque at the propeller flange. Both engine and prop can work in their 'sweet spots'. We must have quite a few 'doing the business' in South Africa now. I have to say this is a job I do enjoy, building these.

[Grumph]

Very nice. Purely out of curiosity, what's the bearing setup for the prop shaft ? What takes the thrust ?

[WilDun]

Talking about casting, I haven't given up yet but have been delivered a severe blow by having my already tiny workspace reduced even more (to a workspace essentially of around 2m x 4m!)
I kept my old bench under which I intend to store my furnace and my welders and possibly my hacksaw (got to get rid of all the junk stored under it though) but my foundry aspirations have still remained intact!
However, I have finally gone mad and bought a relatively large milling machine for this area (RS 30 and a bargain I couldn't resist! ) which I will now have to somehow fit in here as well! - But it has a relatively small footprint and when I get it finally installed on its pedestal (Gawd it's heavy!) then I can mount my micro lathe on the table when necessary and I've now got a Mill/drill/lathe - one man band? - or is it a one stop shop? sort of thing - all very useful for the small over ambitious and probably short sighted foundryman!
It's now a race against time and I would like to have a few years to safely be able to do some foundry work ....... anyway, we'll see

[Flettner]

Very nice. Purely out of curiosity, what's the bearing setup for the prop shaft ? What takes the thrust ?

This is the Long nose version and as such has an extra support bearing out near the prop flange. Normal H6 300 has a double row angular contact bearing just in behind the prop flange, takes thrust in both directions be it pusher or tractor configuration. The long nose version has the same double row bearing in the same position. Gears are light helical, input shaft has a smaller double row angular contact as well to handle this helical axial load. Gears are EN39B heat treated to 60R case hardened. On the tail end of the prop shaft is a roller so that as the gearbox moves with expansion, it won't load the bearing and damage it, as the roller can handle this axial movement. ALL thrust is taken in the Angular contact bearing.

The reason for the design and build of the long nose version was because I saw lots of setups where the home builder would put a four or sometimes a six inch spacer out to the prop! Very dangerous. This is to help circumvent their stupidity.

[WilDun]

This is the Long nose version and as such has an extra support bearing out near the prop flange.............
The reason for the design and build of the long nose version was because I saw lots of setups where the home builder would put a four or sometimes a six inch spacer out to the prop! Very dangerous. This is to help circumvent their stupidity.

Yes and there are some even more stupid designs which some guys have come up with for their belt drive offerings (and intended for sale too)! - I hate cantilevered stuff at the best of times - as with bikes too, eg the shaft supporting the clutch basket etc, I can't see how that makes the primary gears behave nicely toward each other! as for cantilevered cranks eg Scotts and weedeaters etc. no way!
Perhaps axial forces such as in aircraft aren't so bad, but .... I'm told that there are some very heavy gyroscopic forces involved with aircraft props.

Made myself think - now I understand the roller concept!

[guyhockley]

Don't think this has been posted before...
Pattern-making, casting and machining to make a 1650cc, 6 cylinder old-school 2 stroke outboard with megaphones:
http://www.boatracingfacts.com/forum...A-looper-Beast

[Flettner]

Yum Yum, 7075 parts back from being hard chromed.
Might be busy on the grinder today.