Ball tuner

[quadrod]

Hi all, I want to make a ball tuner for my SB13 lathe. I am getting the material to make one like Holescreek did on the PM board. http://www.practicalmachinist.com/vb...turner-130460/ .My question is can i us a ball thrust bearing like this, http://www.ebay.com/itm/140721618765...84.m1423.l2649
or do i have to stick with the taper roller bearing. With the thrust bearing i can get a larger diameter bearing ( am thinking better rigidity ).

[darryl]

Sure, why not. There are also needle roller thrust bearings- many transmissions use them. Some of them take up only 1/10 of an inch. It's my opinion also that with the larger diameter you'll get better rigidity. In any case, you'll have to provide some pre-load from the top, in which case you might want a bearing of some sort there as well. I don't know if Holescreeks project uses that- I'll have to look at it more carefully.

[cidrontmg]

See also http://bedair.org/Ball/ball.html
Ball/roller bearing is optional.

[dian]

do you really need a bearing?

[bborr01]

Tune your balls???

[ahidley]

Ya dont need a ball or roller bearing because you'll get dirt and/or chips in it and it will leave your balls with bumps on them. I personally dont like bumps on my balls!!!

[Paul Alciatore]

Tune your balls???

Rats! Beat me to it.

[john hobdeclipe]

Tune your balls???

Yikes, I'm outa here!!!

[philbur]

That type of thrust bearing is crap at handling radial loads so you may end up with something less rigid. None rolling element bearing is probably the best idea, a bit of friction gives you more control. How many roller bearings in your lathe cross-slide.

Phil

With the thrust bearing i can get a larger diameter bearing ( am thinking better rigidity ).

[quadrod]

Aw crap one missed key! I can certainly make it with out the bearing, that would make it easier and more surface area.

[darryl]

I'd also say don't use a bearing. I would be inclined to relieve the center portion of either the base or the top piece so there's no chance of it rocking. If you create a pocket in the upper part as well, there will be a skirt that hangs down over the base. That should help keep swarf out of it.

[CCWKen]

If you don't have an extended collet chuck like that shown in the photos, that ball turner design is a PITA. I made one (no bearings) and have to use too much material extension to clear the chuck or the headstock when using in-bore collets. A better design is one that rotates over/under the stock from the side. Someone here even made one that mounts in the tailstock. That would work too. The problem is that you need to be aware of your clearances whatever design you choose. Or go out and buy a $400 collet chuck.

[Evan]

Very simple ball turner for a South Bend:

[dp]

Aw crap one missed key! I can certainly make it with out the bearing, that would make it easier and more surface area.

That is pretty much how I made mine.

http://thevirtualbarandgrill.com/machinery/