Taz 6 X-Y calibration difficulty

I have been running a couple of taz 6’s with limited difficulties until I needed to put parts printed on different machines together and they were slightly off in the X and Y dimensions. Printed 30mm test cubes and one machine was printing 30.2 in X and 30.3 in Y. The other machine was 30.04 for both, and Z was not a problem on either. I adjusted the steps/mm through the LCD screen to compensate but this resulted in the nozzle missing the 2nd self leveling pad and barely hitting the first and causing a probe fail.
I don’t understand how changing the steps/mm would alter the location of the pads in the self leveling sequence. Is this the right way to change the calibration? Do I need to change the location in the self leveling sequence, and if so how do I do that? I am using simplify3D. Any help is appreciated.

I don’t have a machine with auto level but changing the steps it does make sense it would miss the washer as every step is smaller.

I think you might check the belt tightness between the machines, if the belt is loose it’s possible it could overshoot a little on each direction and that may be the difference you are seeing. I would however change the SPMM back to what it was (should be the same on all machines).

The difference from one machine to another could be a few different things. The steps per inch of an x or y axis shouldn’t be an issue because the steps per revolution of a motor and the number of teeth on its gear are the same. This small difference you show could easily be due to differences in extrusion, the difference you show is less than a percent. I would start very carefully dialing in the e-steps for each extruder.

Thanks for the help! I thought my belts were tight but after increasing the tension in them and resetting to the original number of steps it is printing just like the other ones. I guess that is the difference between taught and tight. As tmorris9 said the rest is probably due to extrusion, I am running different nozzles on each machine so it is hard to do a perfect comparison.