First of all, great tip with the tape. I didn't draw a line, but I just put one piece of tape over the protractor (the miter angle guide with the angle numbers, for the person who wanted a picture - sorry, I didn't see your message until I was finished) and onto the front of the table, then cut the tape just under the protractor with a sharp razor. I used the edges of the tape to gauge how far I moved the handle.
I think you only need to use the calculator for the first try, after that you can just look at the difference between the previous L & R measurements and the current L & R measurements, and figure out how far to move and in which direction by the difference. At least it worked for me.
Anyway, it's now accurate to .00225 over 6.5 inches. I think that's probably good enough? Should I shoot for less?
Interesting thing. AFTER I calibrated to this level of accuracy, at least the left hand LED guide is now perfectly accurate. I think the right side needs a little adjustment, but so much closer than the first cut I made after unpacking.
Thanks,
Howie