The name says it all - it is a replacement for a table bearing used in @ChrisBorge ball vise.

I couldn't find a real correct size table bearing so I made this one. 

It has little play, but doesn't rotate as freely as a real one would do, so don't get your hopes too high up. Works ok if you don't need the rotation as the most important function or until you find a real one of the correct size. Oil holes provided but aren't easily accessible when fully installed as the adapter plate that is installed on the bearing covers too much of the bearing.  But it works better with a drop of oil.

Printing: 25% infill, 3 perimeters, 0.2 layer height works great and fast.

Installation: Join the outer and inner pieces together.  Screw the inner piece to the adapter plate (4 screws). Don't over-tighten them or the bearing will be hard to rotate. Rotate the adapter plate so that 2 screw holes are visible in the outer piece and screw the outer piece to the index plate (2 screws). Then rotate the adapter plate so that another two screw holes are visible and screw them as well. Again - Don't over-tighten.

Links to @ChrisBorge Vise:

https://www.printables.com/model/842020-open-ball-xl-base

Enjoy!