Sphere drilling jig

[mklotz]

Drilling and tapping spheres can be problematic because it's hard to hold the workpiece and still expose the surface that will receive the machining.

This jig simplifies the process considerably. Two beefy steel "washers" capture the sphere and six machine screws pull the washers together to clamp the sphere.

The whole assembly can be chucked in the lathe or clamped in the mill vise. Orthogonal holes in the sphere are easily done.

If the design calls for it, the washers could be made polygonal and used to orient the sphere to drill holes separated by a predetermined angle. No doubt other possibilities exist.