sphere cutting jig

[Richard Coers]

Just curious... Why are almost all the sphere cutting jigs made to cut such small spheres? It seem like an awful waste of lathe capacity. A 20 inch lathe should be able to cut about a 16 inch sphere...

why think so small?

clint

How many people want wood bowling balls sitting around the house? On the other hand, six or seven 2" balls sitting in a bowl can be very attractive.

[Dwight Rutherford]

How many people want wood bowling balls sitting around the house? On the other hand, six or seven 2" balls sitting in a bowl can be very attractive.

To quote from an old Dell Computer add “That’s what I was thinking”.

[Clint Bach]

I want bowling ball size spheres or bigger. Being able to make smaller size balls should not be a problem for a jig that can make bigger balls.

i guarantee I'm not the only one who would rather have the capacity to make really big spheres. I'm sure there are people who want only very small globes. Many people don't want miniature globes. Basket ball size capacity or larger is more like it for me.

The real question is why limit yourself for no good reason? Maybe larger jigs cost much more but that is kind of a lame excuse. DIY jigs wouldn't cost much more in a larger size. I for one would never buy a jig that would only cut 6" balls for use on my 22" swing lathe. No way!

Clint

[Richard Coers]

Not that it will make any difference between someone purchasing DIY vs purchased, but I'll share my thinking. I make a LOT of my own tools. But they don't need fine adjustment features on them. The reason I purchased the now Carter jig has many reasons. The pivot feels stiff until you use it. In use the resistance makes for a very steady feed rate. You can easily remove the cutter and holder and bring up the tool rest if you want to knock off extra stock. You can tilt the tool holder in either direction to produce a shear cut in the direction of feed. But most importantly is the smooth fine adjustment bolt. So easy to adjust and remove another .005" for making duplicate work. Loosing a bolt and sliding a wood holder forward that amount with a DIY fixture would take trial and error. Mostly error.

[Richard Madden]

I made a sphere jig from aluminum that will turn a 12"-14" sphere (just guessing, have not done one more than 8"). It will also hollow the interior. I read a lot of articles, watched you tube videos, and finally settled on one. I used these drawingshttps://www.piazza-studios.com/downloads , and made a few changes trying to incorporate some things on the Vermec and Carter jigs. The total cost for materials and machining was $110.71. It works good and I'm happy with it.

[Brice Rogers]

John Jordan, For the cutter that you show, is it presented to the wood at an angle - - perhaps tipped forward a bit like the Hercules or rotated axially (like an Osprey?) ??

[Brice Rogers]

I made a sphere jig for my metal lathe. I made it out of aluminum with some of the pieces from aluminum plate and for some of the parts made from my own aluminum castings. I made it to make small metal ball to go onto tool handles.

While it's purpose is to turn metal (aluminum, brass and steel), the basic concept would or could apply to wood as well. Many of the metal-turning jigs look like nested "C" shapes, I chose to do a somewhat different variation. Also, it could easily be scaled up to a larger size. For my purpose, I wanted to make small metal balls to go on the end of a shaft (like for a drill press).
IMG_1404 (1024x768).jpg

[John K Jordan]

Just curious... Why are almost all the sphere cutting jigs made to cut such small spheres? It seem like an awful waste of lathe capacity. A 20 inch lathe should be able to cut about a 16 inch sphere...
why think so small?

With a design like the Vermec one constraint on size is the height of the base and the thickness of the rotating arm that supports the cutter. Make this shorter and the sphere could be larger. There would be tradeoffs between the height of the post that supports the tool and the sturdiness. I can imagine some vibration with a long post unless it was very sturdy.

But really, turning a large perfect spheres without a jig is not a big problem, other than dealing with the mass. David Marks turned one from redwood that started out at 400 lbs, about 40 lbs after hollowing. There are lots of techniques and some simple aids for freehand turning.

JKJ

[Robert Hayward]

The Vermec which I own and the Carter will both turn a sphere somewhere around 12" in diameter if I am remembering the specs correctly.

[John K Jordan]

The Vermec which I own and the Carter will both turn a sphere somewhere around 12" in diameter if I am remembering the specs correctly.

The page from Vermec's catalog:

vermec_catalog_sphere_jig_page.jpg

Looks like this guy's jig will do 300mm diameter: https://www.paulhowardwoodturner.co.uk/jigs-and-things/

JKJ

[John K Jordan]

John Jordan, For the cutter that you show, is it presented to the wood at an angle - - perhaps tipped forward a bit like the Hercules or rotated axially (like an Osprey?) ??

Brice, I just looked at it. The cutter is angled downward a little, not as much as the angled Hunter tools (they are around 30-deg I think). It looks like perhaps 10-deg - I can measure the angle if you need it.

The entire cutter shaft can also be rotated and locked at any angle with an allen wrench.

JKJ

[Bill Blasic]

I have the Vermec and it will cut a 12" sphere.

[Steve Eure]

Not trying to hi-jack this thread, but has anyone have any experience with the ChefWare Kits sphere cutting jig. Seems reasonably priced compared to the other brands.
https://www.chefwarekits.com/woodtur...ll-lathes.html

Also looked at one made overseas. Looks similar to the Carter jig.
https://www.paulhowardwoodturner.co.uk/shop/

[kreig mcbride]

Many reasons for making large sphere:

Making spheres for Victorian building restorations.

Making astronomical models such as the Pluto/Charon system or Earth/Moon System or how about a solar system model, or a Jupiter and moons model.

[Brice Rogers]

Brice, I just looked at it. The cutter is angled downward a little, not as much as the angled Hunter tools (they are around 30-deg I think). It looks like perhaps 10-deg - I can measure the angle if you need it.

The entire cutter shaft can also be rotated and locked at any angle with an allen wrench.

JKJ

Thanks John for the info. No need to measure the angle. I was just curious. If I get around to making some spheres, I'll probably tinker with some various angles.