drilling balls

need to drill some ball bearings of different sizes.

what is best way need to be drilled carefull

they are different sizes and for bosses wife but she won't say what they are for so can't give more info.

I would think that they could be successfully be held in an accurate three jaw chuck and centre drilled using the tailstock followed by the drill to make the hole.

I can't remember if it was the Quorn or the Pillar tool book that recommended making a top hat type split collet for holding balls in the 3 jaw chuck. That's what I used for the ball handles for these tools. I assume you will have to anneal the balls before drilling. Possibly a solid carbide drill will work if the balls are still hard but I have no experience of that.

HTH,

Rod

edited for spelling

Edited By Roderick Jenkins on 09/10/2016 22:03:18

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ER collet holder if you have one.

I recently looked for steel balls on ebay. Some are hardened which is no surprise and some ore not.

Nick

Alternatively ... Drill them on the milling machine [or even the drill, if it's really good]; clamped between two pates, each with a bored hole about 2/3 of the ball diameter.

MichaelG.

It would be helpful to know what the balls are made from, if they are standard balls from a bearing they will be hardened and as such will be a bugger to drill. They are generally case hardened and the easiest way is to grind the case away at a point you wish to drill. Make a collet with a recess to take the ball which should be no deeper than the dia of the ball. Make three saw cuts in the collet equally spaced on the periphery. Place the ball in the collet in the 3 jaw and drill. It helps if the dia of the back of the collet is slightly smaller than the front so the pressure of the chuck jaws is over the ball. Don't try to be too greedy with your drilling as you are only holding on a small area. The chuck jaws should be between the saw cuts. You will of course need to make one for each size of ball being drilled

Rod Jenkins suggestion of using a collet is a good one. If the ball is hardened and you are drilling with carbide you need the shoulder in the collet to keep the ball from sliding back in the chuck.

Yeah, right.

Dusty has given a more comprehensive description but what both of us failed to make clear was that the collet should be blind so that, as John says, the the ball is prevented from being pushed deeper into the chuck. I guess a chuck backstop would work equally well. Tomorrow, I'll see if I can find the collets I made and take a picture.

Rod

Use your sink type spark eroder, especially easy if it has digital readout on the table

John

Buy the boss's wife a string of beads ?

Top hat bush in the 3-jaw, have a back to the bush but also a hole so you can push the ball back out

Or collet with backstop

Edited By JasonB on 10/10/2016 07:20:28

you could hold them in a split bush in the mouth of the hole or pocket radius the same as your diameter and clamp it in a 3 jaw,

Either that or just superglue it onto a mandrel, don't worry, should clean up ok.

If they are very small you could just hold them in a vice with soft jaws and use a dremel to do it.

Jason beat me to it with the 1st suggestion. Definitely more than one way to skin this cat. 

Michael W

Edited By Michael Walters on 10/10/2016 07:24:47

Perhaps he ought to be getting nervous...

en.wikipedia.org/wiki/Georgi_Markov

Neil

(Now how on earth did I remember that?)

It was mentioned on a tv program a few days ago, I couldn't believe it was nearly 40 years ago.

Mike

Found 'em

The slot in the side of most of them was to allow for the arm of a ball handle. The small one at the front was for drilling the ball to go on the end.

Rod

Now you're marked down as a Quorn builder.

Neil

Guilty m'lud:

I sold it -awkward cantankerous thing. This is the only record I have of it.

Rod

Edited By Roderick Jenkins on 10/10/2016 10:02:14

Apparently women use steel balls to redevelop muscles after surgery !! the hole and therefore a string pull is used to retrieve them

Too much information!