Printing Patterns for sand casting

[Vandal968]

I occasionally build running model engines. One kit that I bought a while ago was the Atkinson Engine kit designed by Joe Tochtrop. Joe unfortunately died a few months ago and the kit is no longer available. The model is very detailed and accurate with the exception of the cylinder. On the original engines, the cylinder was round with a couple of flanges on it:
http://m8.i.pbase.com/u8/captain_carl/u ... _orig.jpeg

But, in Joe's version he substituted a water hopper type cylinder which is not correct for this engine:
http://m5.i.pbase.com/u47/captain_carl/ ... model.jpeg

I designed a new cylinder that is more authentic, then added draft angles, fillets and shrink allowance. The cylinder was then split it in-half and patterns were 3D printed for casting. I also designed and 3D printed a core mold so that the cylinder could be cast hollow with all water passages. Here are the core mold and pattern in the first pic. The second pic shows a printed mockup of the cylinder to test fit as well as the cast aluminum part that resulted. Patterns and core box were printed in PLA with a 30% infill.





cheers,
c

[Vandal968]

Forgot to mention. Model Engine Builder magazine is planning on running an article about this process. Great magazine that focuses on model engine building (duh!) as well as general machining techniques.
http://modelenginebuilder.com/

cheers,
c

[jimc]

thats cool. here is an engine a customer gave me to do the paint finish on. he is constantly building these things. its a very interesting hobby. he did alot of research on this particular one which is a rider ericcson. he managed to dig up the original blue prints from the copyright office somewhere. he said it was a rare piece. in any case he modeled the parts in i believe solidworks then 3d printed the pieces and had a foundry cast everything.

[Vandal968]

Beautiful. What is your painting process? I need to figure out how I'm going to do mine.

cheers,
c

[jimc]

i am a professional custom painter so its what i do. i paint cars, motorcycles, mini engines lol. anyway, all the parts were glass beaded, a coat of epoxy primer put down then 3 coats of a red single stage polyurethane. all my paint automotive

[Jules]

If i ever need anything painted, jim is doing it. (Go look at his website - click on his username then follow the link).

[Vandal968]

Wow, beautiful work, but what the hell is this?

http://www.xtremekreations.com/assorted ... [piggy]/2/

Seriously, what the hell is that thing?!

cheers,
c

[Jules]

Wow, beautiful work, but what the hell is this?

http://www.xtremekreations.com/assorted ... [piggy]/2/

Seriously, what the hell is that thing?!

cheers,
c

That's new......... Great pig, jim.

[jimc]

Oh boy, the pig..lol. Well that is a sculpture from some half famous artist. Its an aluminum casting. I have done 5 of those things and are in galleries all over the world. Last # i got was the price tag on that pig was $65k.

[Jules]

Holy crap!

Well, as usual, the paint job is outstanding.