set the front bar so the front end of the fletch is in the middle of the arrow shaft
slide the bottom bar to the right to the mark R
this will be a starting point
Put a fletch in the helical clamp(no glue yet!)and set it on the arrow and check how it lines up with the shaft
make adjustments to the top and /or bottom bars until it lines up right and you have good fletch contact the whole length of the fletching to the shaft.
Tighten up the wing nuts and fletch away!