Sphere on lathe

[Geof]

Originally Posted by jorgepease .....These are friction ball joints for a photo light. At this time we have allot of options available to us including just buying the ball from a ball mfg. and boring holes to press fit stems. That is probably the fastest cheapest way in the long run. Also the ball is not clamped with a knob but by a bushing in back preloaded with belville washers.

Must be a tiny photo light held on a 1/2" ball with a 1/8" stem.

You ask; "Couldn't you just feed the bar a bit further when cutting the other side of the ball closest to the chuck?"

You cannot machine the ball all the way down to the centerline because it breaks off on your roughing cut. You need a small stem still holding the ball until it is finished and then you part off at this stem. I have modified my sketch to show the sequence for doing these complete from bar stock with a small flat at each end. There will always be a little tip left after parting so you will nee to do a final operation to take this off. The small flat is totally irrelevant to your function; believe me, we make an almost identical but larger part used for a different application. One version of our balljoint can hold a maximum torque of 40 lbft.

Incidentally forget about buying and boring balls the most economical way will be from barstock using a barfeeder; per part time on the machine will be well below 1 minute machining brass, aluminum or leaded steel and the hand removal of the tip will be just a few seconds.

[Geof]

Originally Posted by jorgepease ....Edited I am in the middle of converting a manual lathe to CNC. I ditched the compound slide and want to create a custom tool holder. If I can do that, and if I can cut in both directions, then this is what I had in mind, what do you think? I would cut one side of the ball with L then the other side in other direction with R flipped over on other side of piece

I would do something like this, gang tooling, to save toolchange time but both on the same side. The only problem to coming in from opposite sides is sorting out your plus and minuses in the program; one tool has to work with all the signs inverted.

[jorgepease]

Originally Posted by Geof Must be a tiny photo light held on a 1/2" ball with a 1/8" stem.

Yes, it is very small - but there are 42 of them. It's modular with very high tech. electronics.

I think with both tools on the same side, I might have problems with my little bench lathe, if they cut at same time.

I think I can work out the code though, I am playing with this software allot now.

Thanks for you great ideas!!