I' m getting ready to fletch some arrows for the first time.Question is,I got a bitzenburger jig with a straight/offset clamp.I want to put an offset of at least 4-6 degrees on my shafts.How do you determine the degree of offset with out there being any graduations on the jig??I my be making this harder than what it actually is.Also do you adjust both dials or do you only do one?? Clearence shouldn' t be a problem,I' m shooting cxl' s 250 on a mathews 2 prong rest.And yes I' m a little nervous about doing it for the first go around.any comments would help.