I just wanted to start a thread to say how much I like this tool. I bought one about two months ago and have used it while building two dozen arrows. I used it to square off the ends of the shafts, the inserts and the Uni-Bushings. I check my arrows on a spinner to make sure everything is straight. I believe that my groups have gotten smaller since using it. Just last night I was installing my BH's and with one BH/Shaft combination, the BH wasn't spinning right. I did the old method of trying different heads on different shafts and it just wouldn't work. Then I remembered the tool, duh! It was sitting right in front of me on the table and I never thought about it. Put some marker on the bushing, gave the shaft a couple of twists in the tool and screwed on the BH. Perfect alignment! If you don't have one, get one. You won't be sorry.