Pi tape or "diameter tape "Is a tool I recently found on line to add to trouble shooting reels before grinding .In the past I have tried measuring the land x 2 plus diameter of shaft to check for tapering and wear . It is very hard to do it this way and not as accurate as I would like it to be .
I found this one on line fairly cheap . One side of tape is linuar measuring the other is the Pi tape.
The measurment shows the diameter in inches... just shy of 5 "
It's very easy to do and very accurate . Remove or loosen bedbar of reel . Feed the tape around reel and check the measurements . It's so easy to see now if the reel is tapered or at the wear limit . Wear limit for this Toro 3150 Q greenmaster reel is 4.5 " This reel is fairly new as you can tell from the tape . When setting up the reel on the foley I can now double check if it's grinding a little harder on one end off the reel after set up . It's going to eliminate any guess work especially at the lower heights of cut ( HOC )on greens.