A few days ago, I followed the instructions of a video to make a service to the chuck of my mini lathe that presented a runout of couple of thousands. The video said that with an outer ring holding the jaws to make a grinder service.
The result was a real mess, instead of correcting the problem was increased to 10 thousands.
The problem is that the grip should not be external because the jaws have a bit of play.
The grip must be in a natural way, that is towards to the center.
With my problem to solve, I found a video of an older person that showed a system created in the 40's. to do just what I require.
So in the hope of saving my chuck, I decided to design and print a similar piece adapted to my small lathe.
In the end, I was able to fix the mess.
So I share my bad experience and the way I solved it.
If your 3D printer are not perfect calibrated dont do it.
Do it by your own risk.