Grind flats with the Dremmel. So simple. So obvious. And, it's on my list of stuff to do. With the flats and a drop of blue Loctite the collar is on to stay. I have a friend who lost an eye to something as stupid as a flying heli part. In honor of him, I'm careful.
Good tip. Thanks. And I'm going to write that into my Modbar Instructions for making the flybar that I use.