At the beginning of each print, your Axiom will go through it's auto-leveling procedure.  During this process, it will touch the nozzle tip to the metal bed rails at each corner.  It should touch briefly a few times at each point.  If the nozzle fails to detect this contact, it will continue to lift the bed rail up into it.  If this happens, the red reset button on the front screen should be pressed immediately to prevent the bed from raising up further into the nozzle.

The most common cause of the nozzle failing to make this detection is the nozzle or bed rail being dirty. 

  • To clean the bed rails, remove the glass plate from the print bed to avoid contaminating the plate with cleaning solutions, then use a clorox/lysol hand sanitizing wipe to clean off the bed rails.
  • To clean the nozzle, preheat the hotend and then turn it off.  While it is still hot, scrub it with a wire brush.  It's important the the hotend be off while you scrub it.  This is to avoid having a wire bristle touch the two red wires together.  These two red wires with the woven shielding are for the hotend heat resistor.  Shorting this component could blow a fuse or even damage your Rambo board.

Another cause of the issue would be a break in continuity.  The guide below shows you how to detect this.  You'll need a multi-meter with continuity testing.


  1. Go ahead and turn your machine off and unplug it from the wall.

  2. Remove your back panel to access the Rambo mainboard.

  3. Locate the connector with the Orange and White wires in it.  The port on the Rambo is labeled "Z-min".

  4. Unplug this connector from the mainboard and touch one of the multi-meter probes to the exposed metal tab for the Orange wire.  Touch the other multi-meter probe to the Orange sensor wire mounting point on the underside of the heat block.  Verify continuity.

  5.   Now follow the white wire back from this connector to a length of black heatshrink.  Within here is a pin and receptacle for that pin.  Unplug this pin and touch your multi-meter probe to the exposed metal pin.  The other multi-meter probe should first touch the left bed rail.  Verify continuity.  Now, repeat this test only, touch the right bed rail.  Verify continuity.