Chuck jaw truing tool

[olderdan]

Thanks C-Bag, not a lot wrong with your definition of a machinist.
No need for great precision in making the rings as they only have to stop the the jaws from moving and simulate gripping a diameter.
You could at a pinch make one from tube with the cut outs sawn and filed, the accuracy comes from the chuck itself.
You mention using a ring on the outside to do this, the problem with that is the jaws tilt inwards at the front whilst grinding, ending up with the condition you started with of only gripping on the back of the jaws when holding a shaft.
Hope that makes sense.
I dont intend to sell plans , I would rather just pass on what I know and further the cause of home engineering.