I'm doing some sand cast pattern making and I'm looking for something that I could pour over an existing part so that when it hardens it would expand instead of shink.
The reason is that when you cast aluminum it shrinks, about 1.3% therefore your patterns need to be that much bigger.
It follows...
Nuther question for the propeller heads:
Continuing with my last post and the Elliptical bell mouths as being optimal, could you just make the entire runner elliptical? This would create a "tapered" runner for the first half or so, then expand out. Also, it would act like a giant venturi...
I've been reading books, talking to masters and I'm still confused. I wanted to get some opinions from the local propeller heads. Especially Pat.
http://www.profblairandassociates.com/RET_Articles.html
Good info for you guys if you haven't read up. Read the bellmouth article.
The Bell mouth...
