Perhaps you are trying to keep the bobbin cradle in the same place all the time. If that's the case, you might prefer to do what many do. Tighten the cradle so that it can rotate around the vise stem if you desire it to do so but also so that it isn't too loose. You want a friction fit. Then rotate it back and out of the way until you need it. I do this on almost every fly I tie. My apologies if you already knew this.