If the number change by more than ±0.02 then it is not good - you may need stronger structure with less play.
You should calibrate your printer.
Either try Rich Cattell's firmware: [groups.google.com]
or try this approach: [groups.google.com]
or some other calibration tutorial.
You should calibrate your printer.
Either try Rich Cattell's firmware: [groups.google.com]
or try this approach: [groups.google.com]
or some other calibration tutorial.