Steve:
Your not trying to hit a spot when tuning the bow, just shoot it and watch the arrow flight, if its jumping up and down then its nock point. You do not need to paper tune and arrow to set the nock set. Take a square and adjust it to 90 degrees to the shelf, mark the serving at that point, then place another mark 1/8 to 3/16" above that mark. This where the BOTTOM of your nock should be, so the nock set will be much higher than this. Place nock point so the bottom of arrow will rest at that second mark and try it.
Bob