The github wiki page does not exist so I do not know what to do to continue with calibration.
Ah this means that the firmware is telling the motors to spin faster than they actually are physically able to, slowing things down should fix it.
I got worried for a second there that the wiiki disappeared, but it still seems to be there for me. Does this page work for you? Keeping Up · MaslowCNC/Firmware Wiki · GitHub