The Bucket Foundry

[Flettner]

Hopes and dreams

[Ocean1]

Hopes and dreams

Which one's which?

[Flettner]

Dashed by reality, bugger. First two are more gyro cylinders that seem ok but the back two are the FOS / Ryger styles. But they are a cock up. Bubbled badly and leaked.

[Niels Abildgaard]

Hello Flettner

Have You described or pictured Your Gyro engine somewhere here?

[Drew]

I realise that - but there are a lot of fasteners, and it would be hot. Strip one of the threads and unless you have a spare you're fucked.

The Roberts plastic fantastics were quite a bit better for access. Plugs no problem. Engine service, three through bolts out and park the frame on a rubbish bin...

The Warlord is the same. It doesn't inspire me with confidence however on the plastic, but Mr Roberts is a very clever bugger and I've never looked to see how the shell is braced/strengthened at the mounting points.

[Flettner]

Yum, NZ Cylinders nikasil.

Niels, here are some gyro cylinders cast earlier, further back in this forum are some pictures of the engine, page 11 to 14.

And yes on inspection this morning the 350 cylinders have cast well but the FOS / Ryger are a complete fuck up. One problem with lots of cores in a small area is the surface area exposed to the molten aluminium as the alloy fills the cavities gas from the cores is made and released. There needs to be a path for this gas to escape, if not it will escape through the molten alloy causing bubbles / voids. This is what seems to be happening with my cores. Mixing the sodium silicate in richer mixtures make the sand less permeable not so go for gas transport / escape but better for strength. Unfortunately the fix in this case is to make the cores from Shell Core sand but this needs a metal die, with Shell sand being much more permeable and gasses a lot less. I did have a similar problem with the first few 350 cylinders I cast until I went to a Shell sand water core.
All is not lost though as I use this neat little plan. I copy cast my CO2 wood core boxes into aluminium core boxes. Fill with Shell sand and into the wife's oven when she is not looking. Just a lot more work that's all.

[Grumph]

The Warlord is the same. It doesn't inspire me with confidence however on the plastic, but Mr Roberts is a very clever bugger and I've never looked to see how the shell is braced/strengthened at the mounting points.

Around that time there was information coming out about various 'glass monocoque car projects. Some clever engineers were coming up with ways of feeding loads into fiberglass - and going public. One of the best publicised was the Lotus Elite, info about that was readily available - and it worked.
I'd bet there's alloy fabrications glassed in at critical points. Never heard of any of Mr Roberts glass bikes breaking publicly.

[Brett S]

Neil could you coat your shell sand with sodium silicate, ram it in the mould and then CO2 gas it.
Then put it in the oven to cook the shell sand and hopefully burn off the sodium silicate?
It may be an impermeable mess though.

[WilDun]

Will, I just discovered (honestly!) that if you click on a picture, it's description is displayed below it.
Could be useful for those of us who aren't old enough yet (or too old already ) to recognize racing celebrities.

Yes, I'm sorry Frits, (I was 99% sure it was Angel Nieto of course) I mean that's how Jan was involved, but I just couldn't resist, ie being silly in the festive season and having a quick last look at the computer before I went off for a few days holiday. but.... I'm sure they themselves would have been be able to see a funny side to it! - If not, I promise I'll try and keep a "po face" for the rest of the year!- methinks I could have upset Husa. oh no! ................ who's too old?

[WilDun]

Niels, here are some gyro cylinders cast earlier, further back in this forum are some pictures of the engine, page 11 to 14.

And yes on inspection this morning the 350 cylinders have cast well but the FOS / Ryger are a complete fuck up. All is not lost though as I use this neat little plan. I copy cast my CO2 wood core boxes into aluminium core boxes. Fill with Shell sand and into the wife's oven when she is not looking. Just a lot more work that's all.

Bad luck there Neil, but it'll eventually make you a wiser man! (and we can benefit from your mistakes). How did the 350 cylinders compare to the one I saw?
How in hell baking shellsand in your wife's oven is going to escape her attention, I dunno! - you do take some risks!

Anyway, are you aiming to make hollow cores all round, vented from the exhaust and transfer cores into a hollow main cylinder core ??

[Frits Overmars]

just couldn't resist, just being silly in the festive season

I recognize the tendency Will. And judging by myself, it doesn't get better with age. Some people never grow up .

[WilDun]

I recognize the tendency Will. And judging by myself, it doesn't get better with age. Some people never grow up .

Yeah, (judging by myself also) if there is never any laughter, something is amiss, but problem is you (I) need to get the timing right and have people laughing with me and not at me (this can be just as difficult as getting the timing right on any two stroke engine!).

[husaberg]

methinks I could have upset Husa. oh no! ................ who's too old?

Unlikely Will, i was just having a laugh as well. hence the emoticon.

Niels, here are some gyro cylinders cast earlier, further back in this forum are some pictures of the engine, page 11 to 14.

And yes on inspection this morning the 350 cylinders have cast well but the FOS / Ryger are a complete fuck up. One problem with lots of cores in a small area is the surface area exposed to the molten aluminium as the alloy fills the cavities gas from the cores is made and released. There needs to be a path for this gas to escape, if not it will escape through the molten alloy causing bubbles / voids. This is what seems to be happening with my cores. Mixing the sodium silicate in richer mixtures make the sand less permeable not so go for gas transport / escape but better for strength. Unfortunately the fix in this case is to make the cores from Shell Core sand but this needs a metal die, with Shell sand being much more permeable and gasses a lot less. I did have a similar problem with the first few 350 cylinders I cast until I went to a Shell sand water core.
All is not lost though as I use this neat little plan. I copy cast my CO2 wood core boxes into aluminium core boxes. Fill with Shell sand and into the wife's oven when she is not looking. Just a lot more work that's all.

As well as more vent holes, Would making the risers higher help Neil, like a defacto version of the Cosworth pressure sandcast system?

[Frits Overmars]

couldn't resist, just being silly in the festive season.

I recognize the tendency Will. And judging by myself, it doesn't get better with age. Some people never grow up .

(judging by myself also) if there is never any laughter, something is amiss, but problem is you (I) need to get the timing right and have people laughing with me and not at me .

Some BS wisdom (in no particular order) on the subject:


Now let's get back on topic; I'm curious about Flettner's activities.

[WilDun]

Now let's get back on topic; I'm curious about Flettner's activities.

Yes, back to casting etc., but ......... (ie for Frits's presentation!) - not a time for laughter at Neil's place though!