Velocity stack aluminum mold - how would you do it

[SuperRunner]

I have a velocity stack with runner, and I was trying to think of the best way to make an aluminum mold to do lost foam castings.

here is my part.

[Jim Estes]

I'm not sure about the lost foam, but for lost wax I would build a simple mold with a large core to create the center hole, and I would part the mold at the endpoint of the radius on the end of the velocity stack. Most of the investment casting molds I build are made of aluminum with just dowel pins to locate the two halves.

You could build this mold in a lathe using a 4-jaw chuck.

You could also build it out of round stock and not even need dowel pins at all.

Jim

[SuperRunner]

I made a core on the lathe, now I just have to cast the 2 halves for the mold. Probably use plaster and sand cast the plaster halves and then machine the mating surfaces.

[Jim Estes]

Maybe I am not following you here, this looks like your mold is complete. Is it not?

What are you going to cast?

Jim

[SuperRunner]

this is just the inner mold. The outer part you see is the OD of the part, the inner solid stack is the core, or inner ID of the part. I still need to make the outer mold. I will do this by laying the parts on thier side and building a box around the base so I can poor in plaster to the half way point. Then let that set up and poor the other half. Then do a sand casting of the two plaster pieces. I might try to do expanding foam, might be a little easier.

[maquiza]

SuperRunner,

You might want to taper the inside, for an easy part take off.


Jorge

[SuperRunner]

Originally Posted by maquiza SuperRunner, You might want to taper the inside, for an easy part take off. Jorge

I guess you can't tell from the picture, it is tapered, and quite a bit.

[mc-motorsports]

for what it's worth, the original velocity stacks were done by "metal spinning". Would be a lot cheaper unless you wanted it to be extra thick for welding, ect.

[SuperRunner]

yes, I want them thick for welding. I will be welding these to the stock lower runners which are 1/4" cast.

I did a plaster mold last night...turned out pretty good. Tonight I will cast the plaster molds in aluminum and I will be ready to go.