I may have been a trifle optimistic about finishing the learning phase before 20 hours are out. I’m still discovering how to hit a given diameter with a form tool. It seems to be equal parts art and science.
My approach is pretty much to make each tyre individually. Sure I take note of where the flange was cut completely on the first tyre and expect the others to be in the same place. However, it seems to be more effective to stop short of the final diameter, note where I am, and then figure how much further I need to sneak up.
At least the chatter’s mostly gone.