This weekend I Begin the Japanese Maple leaf rosette. I use the the Stewmac dremel base rosette jig and have for a couple of years. I have never had a problem with it. However this time the inner edge of the channel wall for the major ring egged about a 1/32nd on one side. Definitely noticeable. I went a head and inlaid the major ring and packed the void with spruce dust knowing the spruce dust would darken too much when I flooded with CA. I had not cut channels for the leaves yet so I went back to the drawing board and determined where and how I need to locate them to cover the flaw. I had to change the scale and configuration of the leaves a bit. So I am cutting new leaves tonight. It is an easy fix but I hate having to hide mistakes. The only thing I can figure is that the thumb screw was not tight enough and the head moved on my last pass. OOPS
) But, it could be slop in the bearings on your dremel. Mine give me fits when routing bridges for saddle slots. You could try upgrading to a Black & Decker RTX. More power, better bearings.