Okay. I went through a bunch of bother to get my 3D printer more or less calibrated for movement after changing the firmware version. Step one should have been confirming that the steps per mm for movement was correct.
D’oh! (in my best Homer Simpson voice)
It is a lot easier for the other numbers to make sense when you have the steps per mm set right for movement.
What did you use to calibrate that?
Something really low tech. I folded a piece of paper at a 5 inch mark. I know 5 inches is 127 mm. I then made sure it would move 127mm aka 5 in from the bed when I asked it to. I probably should get a stiff piece of cardboard at 10in length and test 254 mm. 10in is basically the limit in practical build size too. Otherwise binder clips or bed edge cooling would cause problems.
I had to mess around with the steps per mm on my prusa because it said it was moving 195 mm when it was clearly moving 210 on the Y axis. Not sure what happened but i ruined my PEI sheet lol