I guess I didn't say it in my post but I've always felt that a critical feature in a self balancing system like the car wheel balancer I described above, is compliance or the ability of the center of rotation to shift. If the centre of rotation doesn't shift there is nothing to cause the balls...
My experience is somewhat different from others in this thread I guess. I bought and used an "auto balancer" for my car many (about 25) years ago with great success. The device consisted of a plastic circular channel attached to a steel plate shaped to fit between the brake drum and...
