My ring to rim fit is not so good on my epi banjo. It sounds pretty good now, and it probably not worth enough to mess with doing a complete rim replacement.
The fit is bad where the inner edge does not sit on the rim. The outer notch on the rim must not be deep enough.
I don't have access to a banjo rim compatible lathe (well maybe I do, but I don't know about the chuck or keeping all the AL filings off everything!), but I've got a pretty good router table at home.
Is it feasible to just setup the router table with a fence to get the depth of cut to just machine this outer edge down maybe 1/8" at most so the ring will sit flush on the rim? If I used the ring surface on the table, the cut should follow that inner surface, and the depth would be controlled by the fence (or bearing on the bit).
What pitfalls are there to doing this? Anybody try it?