ST Clark Sphere Turning Jig

The Clark Sphere Turning Jig is of heavy duty construction in order to be able to make spheres on 12" to 24+" swing lathes. It can create a small diameter sphere but can also create a sphere up to 3" below the maximum swing. A large bar can be used to do very large diameter concave bowls or platters. It is designed with fine and gross adjustment and has heavy thrust bearings.

Clark Sphere Turning Jig includes a 12 " bar with a .75 inch diameter hole in the end which is 6 inches deep, 3/4" holder with one 1/4" HSS cutter, and attachment plate and screw with sleeve. The back of the bar has a 2" deep hole with setscrews to allow attachment of an extension or end handle. Setup for height of lathe but adjustable through about 1 inch. Additional cutters, holders, bar extension and end handle are available as accessories. The side bars shown in the photo are obsolete.

Note the side braces are not as needed so are not included as of 12/2017.

Basic System - Included with 12" holder Bar, 3/4" tool holder with 1/4" HSS cutter. Clark Deep Hollowing System holders, cutters and hollowing bars are compatible. Your tool will be one color of your choice except for the aluminum components.

Adjustment - The Bar is moved in and out coarsely by sliding it (fixed in place by a setscrew) or finely through a lead screw (depicted without threads) in the lower photo. The screw can be turned by hand for slow adjustment or with a drill motor for fast adjusting.

Attachment - The jig attaches to the lathe bed through a pair of large thrust bearings not pictured. It pivots around these bearings to create the sphere. An attachment plate is needed that fits the gap of your lathe.

Lathe Height - The height of the cutter is finely adjustable to match your lathe spindle height. The center sleeve can be changed so the jig can be used on different sized lathes from 16" swing up.

Maximum Sphere Diameter - Diameter of possible spheres vary from very small up to 3" under the maximum capacity of the lathe. Thus on a 24" swing lathe you could cut a 21" diameter sphere.