Losing coordinates while printing

Hi everyone!

I set up the printer in order to print a cell phone case. What is really annoying is after the first layer is done then it loses coordinates and does not begin printing the second layer on top of the first but it moves it several mm … Any ideas?

Try setting the reference voltage to 0.55 do not go over 0.6
Check the pulleys on the motors make sure the screws are tight.
Don’t over do it because you can strip them.
Make sure the bed move smoothly by hand.