Jim's truly simple ball turning tool

[Rex Walters]

The top strap shown should work??

Sure, but I'd want at least one tapped hole closer to the puck. The cutting force pushes down, the longer the lever arm the less rigid it will be.

There's a reason I showed four tapped holes in the drawing.

You can use a cap screw or set screw in the threaded hole pushing down, or a clamp on top pulling up (clamping). Either will work fine.

 

[Janderso]

Sure, but I'd want at least one tapped hole closer to the puck

After thinking about it, I drilled and tapped for a 3/8 -16 hole about one inch away from the puck.
The downward force, as you said, would have to be considered
Getting close to trials.

 

[Rex Walters]

Your photo showed it installed next to a three jaw chuck rather than a collet.

That’ll work fine, of course, but if you do use a chuck, please be careful swinging the handle close to the jaws.

 

[Janderso]

Now that I’m about ready, where-how do I set the cutter? This is a .500” radius puck.
Do I just start cutting taking little nibbles or is there a preset starting point?
Sorry if this has been covered.

 

[Janderso]

Your photo showed it installed next to a three jaw chuck rather than a collet.

That’ll work fine, of course, but if you do use a chuck, please be careful swinging the handle close to the jaws.

Maybe I’ll switch to a collet chuck.

 

[Rex Walters]

where-how do I set the cutter? This is a .500” radius puck.

First make sure the cutter is on center.

Then put a piece of 1" diameter stock in a collet, or turn something down to 1" diameter for at least 1" + the cutter diameter at the end. 1" for the ball, the cutter diameter so you can form a "neck". (Sorry, just realized you wrote 1/2" radius, not ball diameter)

Position the cutter toward the tailstock (handle away from you) and bump it up against the end of the stock lightly (power off).

Retract the cross slide, and move the carriage a little further left, then LOCK the carriage. You want to take off a bitt of metal all the way around the ball.

Now turn on the lathe and start feeding the cross-slide in as you swing the handle left and right, nibbling away the "corners" of the ball.

Toward the end, you'll end up with a mostly formed sphere with a stripe down the side (the original 1" OD of the stock). Your ball is formed when that stripe disappears completely.

 

[Janderso]

I may add another bolt but it was pretty easy cutting with brass. I didn’t have any aluminum darn it.
I learned a few things. Position the puck dead center front to back and the cutting tool has to be set a bit under center height or it won’t cut.
I’m getting there.
The finish is from the cutter. No sand paper. It’s really smooth.
Thank you Jim and Rex!!

 

[Janderso]

First make sure the cutter is on center.

Then put a piece of 1" diameter stock in a collet, or turn something down to 1" diameter for at least 1" + the cutter diameter at the end. 1" for the ball, the cutter diameter so you can form a "neck". (Sorry, just realized you wrote 1/2" radius, not ball diameter)

Position the cutter toward the tailstock (handle away from you) and bump it up against the end of the stock lightly (power off).

Retract the cross slide, and move the carriage a little further left, then LOCK the carriage. You want to take off a bitt of metal all the way around the ball.

Now turn on the lathe and start feeding the cross-slide in as you swing the handle left and right, nibbling away the "corners" of the ball.

Toward the end, you'll end up with a mostly formed sphere with a stripe down the side (the original 1" OD of the stock). Your ball is formed when that stripe disappears completely.

I didn’t follow these directions exactly. Close though.
Next time.

 

[Rex Walters]

I didn’t follow these directions exactly

Nor the drawings. ;-)

It looks like your puck is interfering with your collet chuck. You need to be able to get the puck under the exact center of the ball without anything colliding.

You'll benefit from a step and a longer cutter. At the very least, I think you need a little more stick-out with the stock.

Try steel next time. It cuts just as smooth and easy!

 

[Shotgun]

The cutting force pushes down, the longer the lever arm the less rigid it will be.

That's why I'm wondering why the puck is set off to the side of the cross slide. Is it due to restricted swing on your lathe?
I have a 16" swing. The puck would fit dead center on my cross slide, and I'd still be able to turn balls several inches in diameter.