Spheres and wood threads?

[Barry Larson]

Hi:
I've been nursing a pinched nerve in my back so no lathe time, but plenty of time to plan future projects. A couple of the things I would like to try in the future are cutting threads and turning spheres, so my query is about jigs for these purposes. I realize I could learn to turn spheres by hand and eye, but I am unlikely to turn them often enough or in numbers that would allow proficiency. Therefore I seek jig advice. I've watched a few videos on sphere turning jigs and searched some previous postings here. It seems the Carter Perfect Sphere jig and the Vermec sphere jig get good reviews with the Chefware Ez Sphere unit seemingly less well received. For threading it appears the Baxter jig is the best, without a clear second anywhere in sight.
I did note that Mike Peace seemed to like the Chefware Ez sphere jig once he installed the carbide cutter which seemed to actually cut rather than scrap. The Carter jig also seemed to utilize a scraper as opposed to a cutter although you seemed to be able to orient the cutter for a shear scraping action.
I am tending to lean toward the Chefware sphere jig mostly because l likely won't use it enough for either purpose to warrant say a Baxter for threading and a Vermec for spheres. Up here in the Great White North these two jigs would be well North of $1000 (CDN) dollars shipped to Canada. The Chefware jig including the threading jig (currently on special) would be around $675 (CDN) shipped to Canada and a bit less if I ship it to a shipping point in the US and pick it up myself.
So after all those words. What do folks who have the Chefware jigs (sphere and threading) think of them overall? What are the compromises of the two jigs in use, and any overall thoughts on them? And of course the flaws in my reasoning - I realize multi-use tools are (with rare exceptions) never as good as the single purpose designs, but in this case it appears the Chefware "might" just meet the "good enough for each purpose" test.
Any and all advice is appreciated as always. Thank you in advance.

Barry W. Larson
Calgary, Alberta, Canada eh!

 

[Brian Gustin]

Sphere Turning jig: I made a homemade version that mounts on Banjo in place of tool rest, however it is VERY fiddly to get it exactly centered for a perfect sphere, so I rarely ever use it (and don't really do much sphere/ball turning, though proficiency to do it by hand is very useful when you need to turn nicely rounded parts to a spindle... )

 

[Rick Moreton]

For turning spheres, I recently tried making my own cup centers like in this video: https://www.aswoodturns.com/2020/08/plum-sphere/
Once you get a rough sphere turned you keep flipping between the 3 axes taking a little off until you are satisfied. It was only a 2 inch sphere but it came out good I think. I have seen other people make much bigger ones on YouTube with the same method.

 

[hockenbery]

The Carter jig also seemed to utilize a scraper as opposed to a cutter although you seemed to be able to orient the cutter for a shear scraping action.

The Carter uses a carbide cutter. A guy in Sarasota developed it. I did some testing on it and did some demos for him.
He sold out to Carter. It is probably the best. It also cut concave so easy to make two hollow halves an join them for a hollow sphere. The carbide cutter leaves a smooth surface.


Any jig will work better or faster if you start with a rough ball or an octagon shape.

Turning by hand is more fun and faster than using a jig.
I suggest you try turning a ball with a gouge. Doing a couple will help you with a jig later.
This is a power point I show before I demo

http://swat.hockenbery.net/Turning_a_ball_the_easy_way.pdf

This is ball in a ball demo - the first 10 minutes is turning the sphere.

View: https://www.youtube.com/watch?v=fmCvOP2Mpmw

 

[RichColvin]

I have the Carter Perfect Sphere, and it uses a 6mm cup tool, not a scraper. I also like that it can be converted into a hollowing jig.

 

[Doug Rasmussen]

I have the Carter Perfect Sphere, and it uses a 6mm cup tool, not a scraper. I also like that it can be converted into a hollowing jig.

I wonder why they use a round insert. An insert like pictured below is the ultimate insert for wood. They are used in automatic wood lathes because they cut with or against the grain. But if the tool isn't absolutely rigid this insert could cause gouging because of its aggressive tendency to self feed.

 

[Richard Coers]

With the Carter you can rotate the shaft holding the cup cutter and really get a sharp shearing cut. I love mine. For threads I epoxy in black ABS threads from plumbing fittings. Haven't had a customer complain about the plastic yet. With both fixtures, make some hollow threaded sphere boxes with baseball stitching in it. Sells very well, but hard to make good money.

 

[Bill Alston]

I made my own sphere jig using RCGT0602 inserts. It works very well.

 

[Barry Larson]

I made my own sphere jig using RCGT0602 inserts. It works very well.

View attachment 59618

Bill:
That looks like a Vermec Mk2! Nice job. All I'd need to make that is a metal lathe and a good mill. Maybe 10-12k investment plus materials - oh and about a years practice re-learning any machining skills I once had (minimal). I don't think my financial co-ordinator would buy it:<)! I am leaning toward the Vermec jig just because of the build quality and with the monetary exchange it works out much cheaper than the Carter jig which I also like the looks of. I should add that I stand corrected on the cutter. In the Carter video the tool looks like its scraping rather than cutting until the operator sets it up to shear scrap.
Again nice job on the jig!
Cheers.
Barry

 

[Lou Jacobs]

For turning spheres, I recently tried making my own cup centers like in this video: https://www.aswoodturns.com/2020/08/plum-sphere/
Once you get a rough sphere turned you keep flipping between the 3 axes taking a little off until you are satisfied. It was only a 2 inch sphere but it came out good I think. I have seen other people make much bigger ones on YouTube with the same method.

Turning by hand is more fun and faster than using a jig.
I suggest you try turning a ball with a gouge. Doing a couple will help you with a jig later.
This is a power point I show before I demo
http://swat.hockenbery.net/Turning_a_ball_the_easy_way.pdf

I agree with Rick and Al. Save your money and give turning them by hand a try. My club had somebody demonstrate that method and after an hour of demonstration I came home and was able to turn spheres that are almost perfectly round. It’s much more satisfying than using a jig and you can spend $1000 on something else.

 

[Bill Alston]

I’ve not needed to but the beauty of using a jig is that it’s easy to hit a precise size sphere.

 

[Barry Larson]

I’ve not needed to but the beauty of using a jig is that it’s easy to hit a precise size sphere.

Thanks Bill. That's where I get to. I can turn a sphere by hand without a jig - easy, just turn off all of the non-spherical parts. But, it's way to easy for me to end up with a bead instead of the 2-1/4" sphere I needed when I started turning:<)!
Cheers.
Barry

 

[john lucas]

Several years ago a friend needed to turn a bunch of spheres exactly the same size. We called around and managed to get our hands on most of the ones available. The Vermec was the mist accurate. That being said they all work.
There was an excellent article on American Woodturner years ago that used math and had a chart for those of us who are math challenged. You basically cut facets connecting points and when done you had an almost perfect sphere. Then use cup centers to perfect it.
I have the first chefwarekits threader. He improved it a lot after this. It does a good job. I use the Baxter threader mostly because it's so accurate. The chefwarekit is easier to adapt to other lathes. Being able to convert the chefwarekits jig to either threads or spheres is a good thing.

 

[Barry Larson]

Several years ago a friend needed to turn a bunch of spheres exactly the same size. We called around and managed to get our hands on most of the ones available. The Vermec was the mist accurate. That being said they all work.
There was an excellent article on American Woodturner years ago that used math and had a chart for those of us who are math challenged. You basically cut facets connecting points and when done you had an almost perfect sphere. Then use cup centers to perfect it.
I have the first chefwarekits threader. He improved it a lot after this. It does a good job. I use the Baxter threader mostly because it's so accurate. The chefwarekit is easier to adapt to other lathes. Being able to convert the chefwarekits jig to either threads or spheres is a good thing.

Thanks John. I was hoping you'd reply as I knew you have experience with most of these devices. I'm currently leaning toward the Vermec jig as it does seem to be the best of the whole class. One more question. Can you hollow with the Chefware jig, or does it only do the outside of the sphere? It looks to me like it can only do the outside and any hollowing would be up to me. If I go with the Vermec jig, I'd likely just save my Loonies and Toonies and buy the Baxter threading jig - I've heard nothing bad about it! I really like the quality of other items I've bought from Best Wood Tools, plus they are nice folks to deal with.
Thank you again for the response.
Barry

 

[hockenbery]

But, it's way to easy for me to end up with a bead instead of the 2-1/4" sphere I needed when I started turning:

I’ve did that few times. Maybe more Than that. Any cut too deep reduces the size of the sphere.
When I started teaching spheres I came up with a methodology of making straight cuts to make an octagon cross section.
The cut those corners off. Then you have a lumpy ball. Then smooth curve and use a ring to validate the curve.

I have used this method I lots of workshops and classes. Every student gets a pretty good ball.
The great thing about this method is it teaches you to make a specific curve.
Then by magic the curves on your bowls and hollow forms improve. After doing 10 this way most folks can turn a nice sphere without the layout just using the ring.

Also with this layout I can usually get within an 1/8 inch of a diameter.


Important thing is to have fun and get the result you want.
Jigs are great! Gouge are great.
Have fun.

 

[Barry Larson]

I’ve did that few times. Maybe more Than that. Any cut too deep reduces the size of the sphere.
When I started teaching spheres I came up with a methodology of making straight cuts to make an octagon cross section.
The cut those corners off. Then you have a lumpy ball. Then smooth curve and use a ring to validate the curve.

I have used this method I lots of workshops and classes. Every student gets a pretty good ball.
The great thing about this method is it teaches you to make a specific curve.
Then by magic the curves on your bowls and hollow forms improve. After doing 10 this way most folks can turn a nice sphere without the layout just using the ring.

Also with this layout I can usually get within an 1/8 inch of a diameter.
View attachment 59637

Important thing is to have fun and get the result you want.
Jigs are great! Gouge are great.
Have fun.

I do plan to try to do it by hand as well. I'm just wanting a reliable method to use when I don't feel like fussing around, or I have to make multiples of something for a specific purpose. Thanks for the encouragement.
Thank you.
Barry

 

[RichColvin]

I’ve not needed to but the beauty of using a jig is that it’s easy to hit a precise size sphere.

Exactly. And when making nested spheres, that exactness is crucial.

 

[Dennis J Gooding]

I published an article in the Tips and Tutorial Forum on June 28 2016 called " Simple aid to turning spheres without a jig". The method is graphical and requires no jigs, measurements nor mathematical calculations. It uses a simple graph that can be copied directly from the computer screen to mark the sphere blank for a series of simple cuts that lead to better and better approximations to a sphere. Somewhat later, the technique was extended to allow turning of ellipsoids of various types.

 

[Graham Dolby]

Hi:
I've been nursing a pinched nerve in my back so no lathe time, but plenty of time to plan future projects. A couple of the things I would like to try in the future are cutting threads and turning spheres, so my query is about jigs for these purposes. I realize I could learn to turn spheres by hand and eye, but I am unlikely to turn them often enough or in numbers that would allow proficiency. Therefore I seek jig advice. I've watched a few videos on sphere turning jigs and searched some previous postings here. It seems the Carter Perfect Sphere jig and the Vermec sphere jig get good reviews with the Chefware Ez Sphere unit seemingly less well received. For threading it appears the Baxter jig is the best, without a clear second anywhere in sight.
I did note that Mike Peace seemed to like the Chefware Ez sphere jig once he installed the carbide cutter which seemed to actually cut rather than scrap. The Carter jig also seemed to utilize a scraper as opposed to a cutter although you seemed to be able to orient the cutter for a shear scraping action.
I am tending to lean toward the Chefware sphere jig mostly because l likely won't use it enough for either purpose to warrant say a Baxter for threading and a Vermec for spheres. Up here in the Great White North these two jigs would be well North of $1000 (CDN) dollars shipped to Canada. The Chefware jig including the threading jig (currently on special) would be around $675 (CDN) shipped to Canada and a bit less if I ship it to a shipping point in the US and pick it up myself.
So after all those words. What do folks who have the Chefware jigs (sphere and threading) think of them overall? What are the compromises of the two jigs in use, and any overall thoughts on them? And of course the flaws in my reasoning - I realize multi-use tools are (with rare exceptions) never as good as the single purpose designs, but in this case it appears the Chefware "might" just meet the "good enough for each purpose" test.
Any and all advice is appreciated as always. Thank you in advance.

Barry W. Larson
Calgary, Alberta, Canada eh!

Since you live in Calgary, go to Black Forest Woods as they have both threading jigs and sphere-cutting jigs, both from Simon Hope in the UK.
I have the thread cutter and it's an excellent piece of engineering. I've been tempted to buy the sphere jig but I have so much equipment that I'm controlling myself

 

[Barry Larson]

Since you live in Calgary, go to Black Forest Woods as they have both threading jigs and sphere-cutting jigs, both from Simon Hope in the UK.
I have the thread cutter and it's an excellent piece of engineering. I've been tempted to buy the sphere jig but I have so much equipment that I'm controlling myself

Thanks Graham. I'm sorry I missed your demo at the last Guild meeting - it looked very interesting in the newsletter. Maybe you could consider another demo at a Guild meeting on self control on equipment purchases - I know I would get much value out of such a course:<)! I'll look into the Hope jigs. At least they are a bit closer to order than any of the others - especially the Vermec.
Cheers.
Barry

 

[Graham Dolby]

I made a sphere jig before Black Forest started importing the one from Hope. However, although I managed to cut a decent 4" sphere, it has significant limitations in use.
As for the pinched nerve, long soaks in a hot bath are better than a heating pad

 

[Michael Beswick]

I have the Hope Threading Jig- an excellent bit of kit. Choosing suitable wood is more of a challenge here in the UK

 

[Barry Larson]

I have the Hope Threading Jig- an excellent bit of kit. Choosing suitable wood is more of a challenge here in the UK

Thanks Michael. I must look a bit closer at these.
Cheers.
Barry

 

[Graham Dolby]

I have the Hope Threading Jig- an excellent bit of kit. Choosing suitable wood is more of a challenge here in the UK

Even with hard maple, I coat the wood with thin CA before the first pass with the cutter. I recoat the thread with CA before the 3rd and also the last paths but before progressing, I leave the setting at the previous setting and clean out the thread of any extraneous hardened CA. It might be worth your while using CA before every new pass.