Ball and other shape turning using a follower and pattern

[BCRider]

For a while now I've wanted a ball turning setup. But in addition to ball turning I'd like to make tear drop handles. The ultimate goal being to template turn ball style machine tool handles. You know... The big counterweight ball on one end, small ball with a flat on the other that has a hole for a tear drop shaped winding handle.

It's way down the list but that's the goal. I'd been thinking of how to make up a bit of a bridge that mounts to the rear bed rail that passes over the carriage and has a tracing finger on the cross slide.... A lot of making up stuff to get there.

And then along comes this simple tracer style ball turning rig seen in the video here. There's no reason at all why the tail stock can't just as easily hold a whole ball handle template as it can a ball bearing used for a ball tracing...

Making a Lathe Ball Turning Tool | Tie rod ball pin size reapering tool for lathe machine - YouTube

There will be a little more to it than what we see in the video. To make up a whole 5 to 6 inch long ball end handle it will require tail stock support for the work. So I'm thinking of a bit of a screw on or clamp on shelf for the template It's doable though. VERY doable. And a lot easier than what I was considering.

[RSG]

That's an interesting way to turn a ball! Keep us informed of your idea using the tailstock and it's progress...

[DrMike]

If I were to need such things, I'd go this route

https://eccentricengineering.com.au/products/turnado-freehand-metal-turning-system

[old mart]

It's amazing how such a simple method works, like a copy lathe, but manually following the profile, I like it.

We have one of those shop made variable radius ball turning attachments at the museum, I did try it out once and it did work, but I like this way better.

[plunger]

For a while now I've wanted a ball turning setup. But in addition to ball turning I'd like to make tear drop handles. The ultimate goal being to template turn ball style machine tool handles. You know... The big counterweight ball on one end, small ball with a flat on the other that has a hole for a tear drop shaped winding handle.

It's way down the list but that's the goal. I'd been thinking of how to make up a bit of a bridge that mounts to the rear bed rail that passes over the carriage and has a tracing finger on the cross slide.... A lot of making up stuff to get there.

And then along comes this simple tracer style ball turning rig seen in the video here. There's no reason at all why the tail stock can't just as easily hold a whole ball handle template as it can a ball bearing used for a ball tracing...

Making a Lathe Ball Turning Tool | Tie rod ball pin size reapering tool for lathe machine - YouTube

There will be a little more to it than what we see in the video. To make up a whole 5 to 6 inch long ball end handle it will require tail stock support for the work. So I'm thinking of a bit of a screw on or clamp on shelf for the template It's doable though. VERY doable. And a lot easier than what I was considering.

I like it . Its simple . So I gave you a like. I tried to send you a like , a cool and some kisses but this new forum layout only lets you send one emoji at a time.

[Bob Engelhardt]

Another limitation on the length is that the length of the part can't be more than the distance between the follower and the cutting bit. I.e., between the 2 sides of the 4-way.

[JRouche]

That is kinda cool. Years ago I saw a tracing type attachment for a lathe. I wish I would have paid a lil more attention to the design. It somehow followed a sheet metal shape that was mounted far to the right of the carriage. You had to uncouple the cross slide and traverse a point along the sheet metal form and the cross slide would "follow" the shape. I have seen hydraulic tracers but they are way too industrial for my needs. JR

[Bob Engelhardt]

[...]
To make up a whole 5 to 6 inch long ball end handle it will require tail stock support for the work. So I'm thinking of a bit of a screw on or clamp on shelf for the template It's doable though. [...]

Maybe this sort of thing:

[BCRider]

Dr Mike, I've watched and thought about buying or making a version of the Turnado. It's pretty cool. It's a lot of pieces though. My first look at a tail stock mounted template mount looks like it will be a simpler option.

Bob, yes, as shown with the stylus and cutter spaced as shown it is length limited. But bolstered with a new day's serving of thinking power and a cup of coffee I think I've got an idea that will permit working with templates of up to as much as 8 inches length and a max diameter up to about 1.5 inches. And best of all I only need to make two special fixtures. After that it's just templates and any special shape cutters and matching styluses... Styli?... I looked it up and apparently either is kosher...

I'm going to do a wood mockup a bit later today to see if things actually work out as I think they might. And best of all this setup will not be based on any particular tail stock shape. That should tweak some interest.

[JRouche]

Maybe this sort of thing:

Yup, that sortta. You feel like making one The decoupling of the cross has me stumped. Maybe like what a taper turning attachment does? JR

[BCRider]

Bob, we're thinking along the same lines. But the option I've got in mind is going to be much more compact. Your sketch is close though.....

[DR]

I built something similar to the Turnado linked to in post #3. Mine was meant for wood. One thing I determined was the hand held tool holder piece like the Turnado's had to be fairly heavy to be chatter free, mine was heavy enough to need two hand control. Unfortunately the Turnado is from Australia, in my experience shipping can be nightmare expensive from Australia. Great idea though.

[BCRider]

I agree. It's an amazing idea. But I can see the sort of limits that you're suggesting. And of course with something like that heavy roughing cuts on bigger parts are right out of the question.

One of my first projects I want to do is a roughly 6 inch long and fairly heavy ball end hand wheel for my shaper. That's why the focus on being able to handle up to 1.5" diameter stock and effectively work with a template that is up to 6 or more inches long.

Where I think the Turnado would shine is on smaller pieces. Or where lots of light cuts are OK since the operator is only making one of something. I might give one a try at some point but if this template system works out it'll be good for small items as well as big. So likely this will be it.

[rickyb]

These work well but keep in mind that the tip radius of the follower and the tool need to be the same. Otherwise the part will not exactly match the pattern.

[BCRider]

These work well but keep in mind that the tip radius of the follower and the tool need to be the same. Otherwise the part will not exactly match the pattern.

Yep, that's the plan. In fact I'll likely make two styluses for each cutter. One a little "fat" by something like .005'ish so it holds the cutter a little off the final line for roughing and then a second that is a dead on match for the final finish passes.

So here's the wooden mockup I did to get a feel for this. It's all rather crowded but with the setup shown I can reach in to the rotational center but I can also handle up to 1.5" diameter stock.

This involves a little table mounted below and a little back that attaches with the bracket to the tail stock spindle. This way I can use a live center to add support for longer jobs like ball end hand wheels. The hold on clamp will be from 3/4" aluminium and the table from some fancy 1/4in alu plate I've got. Templates will be cut from something like 16Ga steel and will be mounted to the table with reference to the lathe's center axis.

The first two pictures show the general arrangement for the table and the stylus holder. The holder will be secured in the compound's T slot along side the tool post with a little strip plate "washer" and two 10-32 screws.





And here it is showing the template and cutter all lined up as if looking to start the plunge inward on the simulated bar stock for the small end ball of the big ball end handwheel that is what I made for the template. It looks crowded and when the cutter is in close to the stock's center line there isn't a lot of room left. But there is room. I can remove the template and run the stylus into the edge of the template table which is in line and just below the rotation axis. And there's room for up to 1.5" stock. The pipe shown is slightly over 1.5" OD.


EDITED TO ADD- I lied, the pipe shown is 1.3" OD. And at full plunge I've only got about .06 clearance. So 1.5" or so would require a little longer stylus and a but more stickout of the tool. Like another 0.1".

The stylus finger can just be seen under the mount collar sitting against the end stop which will also be the diameter reference used to set the stylus and cutter to suit the bar stock size.



If the mount shown when locked with a split cotter turns out to not be stiff enough I've got an idea for a bracing arm and screw that will extend along the back of the tail stock to give a second contact point to resist any flex or twisting. We'll see if it's needed.