Unwanted movement after steps per mm change

Hi, I've noticed in the past after changing the steps per mm for an axis in Repetier Host under the Firmware EEPROM Configuration, that upon then executing a Gcode command for that axis, it will first unexpectedly move a certain amount before executing the Gcode command motion. After that the unexpected motion does not occur again until the steps per mm is again changed, and the amount corresponds to how much the steps per mm value was changed from its previous value. For my purposes this is now causing problems, and so far the only way I can find to prevent it is to have Repetier Host Disconnect then Reconnect from the Arduino Mega 2560 after the steps per mm value is changed.
 I would be very grateful if you could explain why this behavior is happening and if there is some way to prevent it besides the method I mentioned?


  • Firmware internally stores position as steps and float value. Changing resolutions means one or both of them are not valid and cause extra movement on next G-move. Correct way is to home G28 after changing resolution or M114 to reset firmware and then home. Luckily you change resolution only until you know right resolution.
  • Ah, got it.  In my application resolution is frequently changed, but resetting the connection seems to be a workable solution.
    Thanks again,
Sign In or Register to comment.