I have a BPE fletcher and never had any problem doing any clamp. The clamp is what sets the spiral,the bar is to adjust the amount of offset you want on the shaft. On the bar(magnate) you should see lines set in a shaft, put a feather in the clamp(no glue), then loosen thumbscrews to make adjustments(both end usually have to move), when where you want it lock thumbscrews and glue up 1 feather and look at it ,if right got town, if not re-adjust.When set up write down the # of lines for each end of bar either up or down from 0. Hope it helps.