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Arbo
08-12-2004, 12:17 PM
I have a few large diameter ball bearings that I would like to drill and tap for use as ball handles. I know that these things are HARD. I was wondering if it would be possible to anneal them, and how should I go about it?

Evan
08-12-2004, 12:28 PM
Have a ball bearing barbeque this weekend.

sch
08-12-2004, 12:46 PM
There was something in HSM or PM about this
a while back. Basically heat to near red
heat and cool down slowly to anneal. Lots
of polishing afterward though. As Evan
says put them in the BBQ pit, dig out next day. Wrapping in stainless foil will reduce staining. Steve

SGW
08-12-2004, 12:49 PM
They'll anneal, but even in an allegedly "soft" condition they'll be no joy to drill. Bearing steel is tough stuff.

Even's got a good idea -- put 'em in your charcoal barbeque and let the coals just burn out, so things cool down really slowly.

Small Parts www.smallparts.com (http://www.smallparts.com) sells balls of various materials, including brass, which would be a whole lot easier to drill, but that would take all the fun out of it.....

Evan
08-12-2004, 01:14 PM
No need for SS foil. Put them in a small flat tin can like a pocket tobacco can with some borax and they'll stay bright.

ibewgypsie
08-12-2004, 05:18 PM
I got a small indexer I am mounting a compound and toolpost onto.. I started this about six months ago. (after the HSM ball maker article).

When I get it together, wouldn't that make decent ball handles? Just set the compound on the indexer from center to the radius, and turn indexer back and forth?




------------------
David Cofer, Of:
Tunnel Hill, North Georgia

CCWKen
08-12-2004, 05:35 PM
Yep. Don't need to wrap them. They'll polish up to a fine chrome finish, if you have a buffer. I've even cut the sides down to give them a barrel shape. Make nice looking knobs.

darryl
08-12-2004, 10:27 PM
I've drilled bearing balls before. Not easy, but not that hard. I put two bricks together at an angle, so there's a vee at the junction, and just laid a few balls in the vee for heating with a propane torch. Heated to cherry red, let them alone a while. Hold them in the lathe chuck for drilling. Keeping the bit from going off center was the bigger challenge, but that is overcome by first putting a drill bit in the chuck, then drilling a hole in a piece of stock held in the tool post. Without moving the crosslide, that hole centers the bit, which is then coming from the tailstock, and the ball is mounted in the chuck.

Tapping the hole was no fun, and it's best to drill an oversize hole for the tap, for maybe a 50% thread. Using a bottoming tap in a blind hole won't be fun either. Overall, probably best to silver solder a nut to the ball. Chuck a bolt to thread it onto afterwards, to clean it up.

[This message has been edited by darryl (edited 08-12-2004).]

mochinist
08-12-2004, 10:31 PM
Darryl: When drilling something round or odd shaped and you have a tough time getting the spot drill to start just take a small diameter endmill and cut a small flat spot, then you can drill away no problem.

darryl
08-12-2004, 10:41 PM
The flat spot is a good idea, mochinist. I still have problems keeping the bit on center, probably because the point of the bit isn't precisely centered to begin with. Something to do with the tailstock axis not being precisely alignd with the ways (definitely this is not a toolroom lathe)