View Full Version : Ballpark numbers for 20" spun aluminum sphere section...


InspirationToolworks
12-01-2005, 08:26 AM
This is NOT an RFQ... I just want to know *rough* prices so I know where to add spun aluminum to my design toolkit.

What I would be looking for:

A section of a sphere, 20" in outer diameter, with a hole 13" in diameter at one end, and a hole 6" in diameter at the other. The holes would be at opposite ends.

I'm thinking maybe 1/8" thick aluminum, maybe with a small registration flange at the 13" hole.

I'd be looking in quantaties of 6 to 12.

I just need ballpark info... are we talking $20 each, $60 each, or $180 each?

Thanks!

-Jeff

InspirationToolworks
02-10-2006, 03:50 PM
Anybody?

-Jeff

dkowalcz
02-12-2006, 11:36 AM
Well, there must not be many metal spinners here... That would take a pretty good sized lathe - I can find out what that would cost for you if any of the local shops up here could take it on, but as a WAG I'd say the 3rd number is probably the closest.

Figure it's about 8 sq feet of aluminum to build from with the extra wastage and clamping, and around here 1/8 thick in 5052 (a good heavy forming alloy) is about $5/sq foot, so that's $40 right off the bat. Then someone needs to make a form, and actually spin it. The form needs to be of the collapsing type, otherwise it'd be stuck in the part after the spinning is done so it's not a trivial effort, but not hard either. It may cost much less to make as two welded hemispheres though.

I'm not sure any annealing would be required, I doubt it, but I'm not a spinning expert either by any stretch.

So, whatchya buildin' anyway?

InspirationToolworks
02-13-2006, 11:21 AM
Just looking at options....

Take a look at this website: http://www.mag1instruments.com/

A two part ball is a possibility, but the seam would have to be quote smooth and of a fairly constant radius.

Thanks for the feedback!

-Jeff