Just bought a 4th gen model of the MB Replicator 2 and I'm having a couple problems with it related to the y-axis calibration. I put in a support ticket for the problem, but I'm still waiting to hear back.

Printer: MB Replicator 2, 4th Gen
Firmware: 7.6
Software: MB Desktop, v3.9.1.1143

The issue started when I tried to print the bolt and nut that comes preloaded on the SD card. It printed fine, but it was more oval shaped...longer in X than in Y. Next I tried printing the 20mm cube example that comes on the Makerbot Desktop software. Again, it printed, OK but the cube measures 20mm in the x-direction and only 17.8mm in the y-direction. I have since tried printing several calibration objects and they are all too small in the Y-axis.

Both the Onboard preferences and the .jsom file associated with with software list the steps/mm as 88.573186. I have read online where people modify this value slightly to correct printing accuracy...but the changes are always small like 88.888888. To see if it would fix the problem I changed my steps/mm on the y-axis to 99.520433 (88.573186*20/17.8) in both the onboard preferences and the .jsom file. Printed another cube, but it didn't change anything. To see if these changes were even working I changed the x-axis to 99.520433 and again no change...still a 20mm x 17.8mm cube.

So, I'm at a loss for the moment. I figure the y-axis stepper motor probably has a bad output signal and needs to be replaced, but I don't know why my changes to the steps/mm are having no effect to either axis.