I'm new to castings and am playing around with designing an iron sand
casting for a machine tool base I have in mind. Could any of you
casting veterans help me with these questions:
(the casting will be about 1500 # and will look like a typical "grate"
style you see for the beds of machines)
1. Is there an avg price per pound for gray iron and also for ductile
iron that I can compare (I can adjust the size of the casting on the
strength of the material)?
2. What is a typical draft angle?
3. What is a typical minimum inside radius? (smaller is better for me
from a weight/cost standpoint)
4. What is a typical minimum wall thickness? (I'm debating going
between more thin walls or less thicker walls).
5. What is a typical shrink factor? Just need an overall, nothing
fancy for thin vs thick areas.
6. I need to have some 3" holes that get bushings pressed in. Should
I just plan on post-machining these or will the holes be accurate
enough as-cast? IOW how close of tolerance can be held for a 3"
through-hole that is about 10" deep (please don't try to impress me
with a GD&T- answer, just a simple tolerance is fine :) )?
7. Can you recommend any casting houses that can do this size of
casting but that are *affordable* (mom-and-pop type foundries)?
- posted 16 years ago