After talking with SteveG about the method, I had to go try spin-welding a screw to a hard steel ball.
Nice results!
What was your method? Drill? Lathe?
Yeah, I’m interested in what you used, I’d be afraid to harm the bearings of any of my shop tools by doing this. (I don’t want to research replacing 1962 South Bend bearing shims)
The screw is 6-32, so the forces aren’t big. I used a HF lathe with the screw in the tailstock drill-chuck. I generate higher forces drilling or rough cutting.
Used Max rpm till I got glow, thin stopped while increasing pressure.
If you have a lathe why not just turn them?
Or am I missing some thing.
@Nigel_Dickinson Turning a ball is hard to impossible on a manual lathe. (Without a complex/expensive radius cutter tool) You can do it on a CNC where the computer can create synchronous motion in 2 axes to create a curve, but even then you might not get the surface finish of a polished ball bearing.
I thought you could buy these kinds contraptions off the shelf, or am I mistaken? I mention because I had a project in mind to use something similar.
@Sanjay_Mortimer I always manage it using tool steel and grinding wheels. Old school so there you go am I missing something?
after all before CNC’s I was making stuff like this on lathes that were design to hold 4 thou in old money…we held it to less than a thou.
And with 63 micron finish or better.
I think the issue is one of precision and quantity. I can turn an oblong-like shape on the lathe, but the average Delta’s going to need 12 of 'em. A 3-jaw chuck will naturally center a Steel Ball, and making 12 of these could be done in under an hour.
The level of roundness of a modern manufacture hard steel ball is well beyond what can be turned on a lathe, cnc or not.
The key is to have an attachment to the ball while keeping it’s hardened condition.
The only other way I know is to EDM a pocket or thread. Not something in a typical home shop.
@Mark_Fuller but your printed cup will be outside of the balls tolerance…hence why people buy RC or industrial ones.
Seems your concerned about the ball when its both in tandem.
@Nigel_Dickinson I’ll be making a precision molded epoxy cup. The plan is to use a ball as the form. I have some resin that has molybdenum disulfide as a filler. The cup will run dry but be self lubricating.
@Mark_Fuller so a lot of work when off the shelf is available.
But that means you could of machined them.
But each to there own I suppose.
Different Strokes for Different folks, @Mark_Fuller has to answer to no-one but himself. The conversation is enlightening.