I am yet to get one of these scopes, but did notice that it seemed rather hit and
miss in some of the video's that I have viewed, and also comments in the forum.
My first thought was if the control knob simply pulled off without dis-assembly then a foam or
soft rubber washer or similar between the rear of the knob and the case may act as a brake.
If it worked out, it could be an easy and quick remedy for some of those having trouble,
obviously not the ideal solution as a firm indent would be better, but may be worth a try.
Muttley