You can't set it for exactly 5 degrees, on a Bitzenburger anyway. You are limited by vane to shaft contact. On the Bitz you adjust the knobs until you have offset and the entrire vane contacts the shaft.

Only way to measure it would be to draw lines on the shaft and use a protractor I think? You could then vary the position as the jig allows.

Does that make any sense? Bohning now sells a jig that comes pre-set from the factory for the recommended offset of blazers.