where to get steel?

I'm interested in making a graver's ball for myself. It is basically
a 4, 6, or 8" sphere of solid mild steel with a wooden ring on bottom
for it to rotate in, a vise stuck on top, and several bearings inside
so that it can rotate at the equator. I'm fairly new to machining, so
a 4" ball vise will be good practice if nothing else, and still useful
for small items, although what I'm really interested in is machining a
larger 6-9" diameter ball for myself. Most parts are fairly basic.
But where can I get either a 6-9" ball (i.e., if anything on earth
might use ball bearings of that size, which I could scavenge?) or 6-9"
solid mild steel rod from which to machine the ball in separate
hemispheres? I'm building it half for fun, but half to save money, so
if it costs me $2+/lb for the steel it's not worth it. Any ideas on
where to find stock, perhaps some sort of scrap, of such a dimension,
and affordably? I live in Cambridge, MA.
-Bernard Arnest
Reply to
Bernard Arnest
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in Meriden CT. I was there a couple of weekends ago and they have a large selection of steel in the odds and ends building. I don't recall if there was any stock in as large size as you are interested in but it might be worth a call or email. Their price was $.75 per pound.
Errol Groff
Instructor, Machine Tool Department
H.H. Ellis Technical High School 643 Upper Maple Street Danielson, CT 06239
New England Model Engineering Society
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Reply to
Errol Groff
Try a large dealer in heavy duty construction equipment. A vibratory compactor used for compacting highway subgrade material uses a pair of very large diameter steel balls rotating inside a pair of ball bearing races - one on each end . The balls are free inside the race, and come up to speed to produce a eccentric force that is transmitted to the ground. Dave
Reply to
David Anderson
Just a heads up...old bowling balls get used a lot for this sort of work. And its easy to mill a flat in it for the vise, tap well, and may be dropped into a small trailer tire sans wheel for stability.
And you can pick em up at the Goodwill for $5
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
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