Balanced ball handle using ball turner

[Pacer]

Adding a bit to the recent post on ball turners - I was in the process of turning up new handles for the cross and compound feeds and adding larger dials on my SB 10L and thought a pic of the (almost) finished result of the compound handle, dial, and a different take on the funny looking nut South Bend used on the handles (mine were missing and I didnt like them anyway). I still need to finish the compound handle/dials and then I will set up and stamp the dial numbers and hash marks.

The old, pitted SB handle is beside the new one...

 

[jgedde]

Gorgeous! I need to wipe the drool off my keyboard!

John

 

[jgedde]

Presumably it will be a zero set dial? I made a set for my Atlas with a ball groove inside the dial and spring loaded balls inset into the spindle. This makes the dial turn as smooth as silk with virtually no drag. They don't look nearly as nice as yours though... Be sure to post a picture of the finished handles/dials!

John

 

[Pacer]

This makes the dial turn as smooth as silk with virtually no drag.

Yes, itll be a zero set, but the dang thing spins so freely now that I'm a bit concerned about locking it down! Was thinking to use a set screw type gizmo pressing on a brass insert, but your ball set-up sounds interesting. I'm not quite getting a picture of your set-up, could you elaborate?

I am installing thrust bearings on the shaft, which is only 3/8" dia, and that limited the way I had wanted to make the dial - at least so far, I'm still pondering on that. I wanted to use a friction slide like on the newer lathes.

 

[jgedde]

My lock doesn't use the balls. It's simply a knurled brass screw.

As far as the balls, think of a radial ball bearing. The outer race has a groove the balls travel through. This is what you'd make inside the dial's bore. Instead of having an inner race and a ball retainer, you drill 3 holes radially into the shaft that holds the dial. In these you insert springs followed by ball bearings. In other words spring loaded balls which ride in the groove inside the dial bore. This technique also negates the need for a thrust washer since the balls in groove holds the dial in position on the shaft axially.

I made a sketch but can't seem to find my scanner software on my PC.

Let me know if you're still confused by my description and I'll try harder to get the scan to work.

John

 

[Pacer]

John,

Ahhh! now I gotcha... I think that is actually a variation on what I mentioned, calling it a "friction slide" I have a Taiwan 13x36 South Bend and the knobs/dials are set up with this type arrangement. Sorta uses the same principle as your balls, with the little arched shape piece of spring steel instead of balls riding in a groove causing enough friction as it rotates around to not need a locking device.

This pic is handle/dials I made up for another machine I had and had wanted to use a similar arrangement on this SB, but couldnt figure out how to incorporate because of several factors different from the dials in the picture. Hopefully you can see what I'm talking about...