Z probing in the wrong direction with inductive probe.

  • Hi,
    I keep getting an error on Duet WiFi when trying the do bed leveling with my inductive probe Error is: G30
    Error: Z probe already triggered at start of probing move. If I cover the probe till the light comes on it well, sort of works. Getting very confused with this Gcode. How is the probe calibrated and why is it going backwards???

    Thanks guys/gals

  • You need to use the I1 command to invert the signal, refer to my first post on probe setting configuration.

  • administrators

    To elaborate on that, add parameter i1 to your M558 command in config.g. Or if it already has i1, change it to i0.

  • OK thanks guys, got the Z direction working. Now I have problems with the mesh compensation , keep crashing into x stops. The probe is working great but getting a file together without issues is a mission. Has any kind person got a file the matches my ender3 pro bed size 220 x 220, or a start file I can modify.


  • Do you have the bed size set correctly? Have you set the offset for your probe mount?

  • Silly question were do I set bed size?

  • Moderator

    It's set by the m208 command in config.g

  • Yes that is set correctly

  • Solved my issue with bed leveling . Getting the hang of the G-codes. Just a few more questions if anyone is watching and can answer. After doing a bed level with G29 (no options) does it use the same map every time. and it seems to scrap the nozzel along the bed when goin to the start point for the print, is this in the bed .g file settings which I seem to have deleted ☹ so I would also like a starting point for rewriting the script if it is involved in my issue. Also I have calibrated the probe with the nozzel touching the bed and sent a G92 Z0 to the board and then G30 S-1 to probe the bed without resetting the Z=0 position and entered the z figure in the offset in the config file for the probe but it it still seems to low and I have to do baby steps to move it up !!. Learning and it is great fun. Thanks for the help guys/gals

  • administrators

    @dumbo said in Z probing in the wrong direction with inductive probe.:

    After doing a bed level with G29 (no options) does it use the same map every time

    Yes, until you use either M562 or G29 S2 to cancel mesh bed compensation, or you power down.

    G29 with no options also saves the height map to the SD card, so that you can use G29 S1 to reload it.

  • I used to have that scraping issue sometimes as my bed was not well trammed and without the mesh it would be too close in places if you didn't give it some +z on move. To start I did the typical paper tramming, but then used the mesh visualization to start tramming the bed better. After a few rounds of that I had much less slope in the mesh bed compensation. Then I went through the process of setting the z offset for the probe in the wiki again and I can usually print without any babystepping anymore. I also replaced my adjuster knobs with those nylon cored locknuts so they wouldn't vibrate loose and lose my settings.

Log in to reply