Bed leveling assistant not responding

  • Can anybody give some advice on how to get somewhere with the levelling assistant that pops up whenever I go to print a file? I'm using a DuetWifi with the latest firmware and web software, controlled from my laptop. My printer's a DIY i3 clone cartesian. I don't have an automatic bed probe.

    When I run the z home an assistant pops up and I can control the Z axis with the buttons and lower the head until it's gapped properly with a sheet of paper. I can even run the mesh compensation probe and probe for multiple points.

    when I queue up a print the bed levelling assistant pops up but the controls don't work, I can't move the printer head. The head is raised very high off the bed while it's doing this so I can't gap it with a piece of paper.

    My bed is square with a manual m3 screw at each corner.

    I looked over the documentation and saw that bed.g has to have S4 at the end for 4 screws. I also have an M671 at the end of config.g listing the locations of each of the 4 levelling screws with a P0.5 at the end for 0.5 pitch for m3 screws.

    I've attached the config files which should be pertinent.


  • administrators

    As you don't have a Z probe, do you have a Z endstop switch? If so, see item #1 on the wiki FAQ page.

  • Thanks @dc42 that got me further. Now I'm running into a problem where the G92 command at the end of the homing of the z axis isn't setting the z position properly.

    If I execute the following gcode commands in the console this is what I get:

    G92 Z0.1
    X:20.000 Y:20.000 Z:1.000 E0:0.0 E1:0.0 E2:0.0 E3:0.0 E4:0.0 E5:0.0 E6:0.0 E7:0.0 E8:0.0 Count 2000 2000 400 Machine 20.000 20.000 1.000

    Because it thinks it's at 1mm after the homing the first layer is printed incorrectly. What do I have to do to correct the homing?

    Here's my home z file:

    G91 ; relative positioning
    G1 Z10 F200 S2 ; raise head 10mm to ensure it's above switch trigger height
    G90 ; back to absolute
    G1 X20 Y20 S2 F2000 ; put the the head where you want it to be when you home z
    G91 ; back to relative move
    G1 Z-200 S1 F100 ; move z down until the switch triggers
    G90 ; back to absolute mode
    G92 Z0.1 ; tell the firmware that we are at z=0.1mm, the width of the paper used for homing (measured with calipers)

  • Never mind, i figured it out. The reprap firmware configuration assistant was using M208 to set the minimum z height to 1mm. I changed it to 0mm and now when i run the calibration I'm getting 0.1mm as expected.

    To be honest, the configuration assistant was more trouble than help. I'd almost recommend not suggesting it in your documentation.