Jim's truly simple ball turning tool

[Janderso]

Lol!

There are four pages!

On the first page, my only page, it said 1/3.
I then went back and found your link to the four page document and was able to print the complete file.
This would have saved me some time!!
Chasing my tail is a pastime of mine

 

[Rex Walters]

X Z Kellering and file is easy

Cool.

This is the first time I’ve heard of Kellering. Apparently it’s also called tracing.

It sounds similar to following a 3D form on a pantograph engraver.

What kinds of things have you made with the process? Can you describe it in more detail? I’m quite curious.

 

[Fasturn]

Cool.

This is the first time I’ve heard of Kellering. Apparently it’s also called tracing.

It sounds similar to following a 3D form on a pantograph engraver.

What kinds of things have you made with the process? Can you describe it in more detail? I’m quite curious.

Kind of a term use many ways. Before cnc it was tracers and panographs ( GK 21 Deckel ) I used to run for mold cavities / engraving. Term not used much today because it's step milling and profiling 3D.
When roughing out profiles on large parts ( CNC ) we Keller with a flat endmill or small radius to save time. Then a Ball endmill to finish, but not always. Here's a video that might help.

 

[Jimsehr]

I've just posted the first two parts of my build series for beginners on my blog.

I've also made several updates to the 3D model and dimensioned drawings. The last page of the latter will be particularly helpful to anyone attempting to build one of these.

I'll update the top post with these links as well.

Please let me know if you do end up building one of these! It's a useful tool and quite fun and satisfying to use.

 

[Jimsehr]

Rex,
Maybe I missed it.
How are you locking the T body into the T-slot?
I’m thinking a simple 1/2” thick top strap bolted into the center of the T body.
So far so good. Working on the one piece T block now.
I have a 5 degree back rake on the carbide.

Jeff
This is my design and I have been using it for years . I have no problem with finish. And if you make the tool like i do you don’t NEED any relief. But if you want Kennametal and others make a 1/4 inch round carbide insert that is shaped like a ice cream cone that works perfect for the turner.

i don’t know why but everybody wants to make my design BETTER .
One other thing most people cann’t seem to get in their head is the same SIMPLE
tool does is two functions it cuts balls and it also cuts a radius into the od of a bar.
Another thing my tool can easily be made without a mill. It can be made on a lathe with ease and you can control ball or radius size to a couple thousands
true size. Making a 1 1/2 ball is simple if you need that size.
A simple puck can be made for many different sizes very guickly with ease.
I know Rex has seen my tool working for a ball shape or a radius cut into a bar
od . And Jeff you know and have seen some of my tools work.
And before you start making a ball turner give me a call
and I will be happy to explain more about tool.
you can also google Jimsehr ball turner to watch it work.

 

[Jimsehr]

Rather than making one for each size, I think it would be easier to mill a slot like on a fly-cutter, and then have a small bar with the hole for the cutter. The set screw would then hold the bar in place.
This does look like an easy yet useful project, though.

I have made the tool with a sliding tool and found the best and quickest way for me is use a stationary hole for any size radius I want. First you don’t have to do trial cuts to find radius. And you could easily make about 6 different radius in one puck. 3 pucks would let you make about 18 different radius cuts. And the radius are true to size every time. I could probably make the 3 pucks faster then you can set up one radius. As Rex knows I first make a tool then try to make it more SIMPLE not more complex.
Jim sehr

 

[Jimsehr]

I was thinking the same thing, @RJSakowski .
I figured I'd put a couple threaded holes in my existing QCTP t-nut. Then I'd take the "extended" piece of the design, and screw it's base to the t-nut. Maybe that would make it even one less piece @Rex Walters ?

Ooh! Ooh! I know. How about I drill a hole in my existing t-nut to hold the cutter, and then use the compound to spin it? I'd need to add a short bolt to force the t-nut up like Rex demonstrates.

The swing point of the ball radius if in the center of the cross slide makes you have a lot of stick out. More prone to chatter. If made the way I designed the tool the ball only has about
A half inch of stick out. After over 70 years of machining I give a lot of thought to the design. And as far as making the cutter slide to change ball size. I can make a new puck faster then you can adjust sliding cutter and know ball size before cutting the ball. That is why I made the cutter hang over the side of the cross slide. Seems like everyone wants to change my designs. This tool also cuts a radius into a piece of bar material. So you are making 2 tools in one.

 

[Rex Walters]

I can make a new puck faster then you can adjust sliding cutter

I note Jim didn’t even bother to make a handful of pucks at nominal sizes. He pokes holes in his pucks as specific needs arise.

For oddball radii it isn’t even worth making a new puck. Just drill a couple more holes in an existing puck to hold the cutter at the radius you need (one in the face, one on the side), then tap the hole in the side for a set screw.

 

[GeneT45]

Finally got my 'roundtuit...

All designs should be this elegant. Incredibly simple, without compromising functionality. I'm impressed. So impressed that I'm only going to make one improvement... ...a ball turner should have a ball handle that it produced!

And that's the ball.

GsT

 

[Jimsehr]

Finally got my 'roundtuit...
View attachment 504878
All designs should be this elegant. Incredibly simple, without compromising functionality. I'm impressed. So impressed that I'm only going to make one improvement... ...a ball turner should have a ball handle that it produced!

And that's the ball.

GsT

It also turns a concave radius into the od of a bar. When I make a tool I try to make it SUPER simple. Almost everyone seems to want to make it more complex. It’s harder to make it simple . They seem to want to add ball bearings or a movable cutter. They don’t see that makes tool more complex. To see it working google Jimsehr machinist.