So, I am quite sure this is not an original thought, but I have not heard it mentioned so I thought I would.... Since rolled ball screw error is progressive along the screw (+/- .004" per foot for most rolled screws I think), can't the software compensate for this quite easily? I did it this way on mine. I had my machine make two vertical swipes 4" away from each other. Then I just measured the actual distance between them. Sure enough I was off by a couple thousandths. You can then adjust your calculated encoder counts per inch in the software to compensate. Before my encoder count was something like 31,994 per inch and now the compensated amount ~32,005. I know this makes some assumptions about lead error but overall, is this logical? Thanks

I believe that EMC let's you map the leadscrew so that it can constantly adjust to compensate for the screws innacurracies.

With your way, you could move another 4" and be off twice what you were before you "compensated". That +/- .004 can be anywhere on that foot, and it can be different from 1 foot to the next. You should be good for that 4" section, but all bets are off for anywhere else. But you'd really have to do a lot of checking to be sure.

True enough, but I think due the manufacturing processes of these screws that the error (if any) is indeed proportional. I do know this. If they have a tolerance of .004" error per foot, there is no way that a screw could have the .004" trapped in one inch. While this meets the tolerance, they would be scrapping about 97%+ of their screws. I have been checking the rest of the screw. I will update.