No BlTouch readings



  • In my experience witht eh BLtouch, the web interface rarely responds fast enough for the probes super fast pulse, to get it to register occasionally i would have to deploy the probe, and then manually press the pin multiple times to get it to register once. Also, unlike a mechanical switch, 2-wire output for the touch seems to be polarity sensitive. On both my Rambo boards and the duet, polarity has mattered.



  • I already checked polarity and wiring a few times…
    What happens with the output of your Bltouch when it is in Alarm mode? I did read that it then has continuos Signal output so we should be able to measure some kind of voltage.
    I also checked it with pushing the pin like 300 times up und the webinterface didn´t react once...
    I only get a reading if I disconnect the output wires


  • administrators

    It does sound as though your sensor is not producing any output on the signal wire.



  • Right now I am setting the Touch up with the old board to see if it still works.
    But the config is right yes? Becaus it says : "Z: at min stop, Z probe: not stopped"
    And one more thing because I didn´t find something about this. Were do I need to home when I home with the probe? From Smoothie I am used to home at the first probe point.
    And will the IR sensor be in stock soon? Might wanna try it out


  • administrators

    Is the IR sensor out of stock at duet3d.com? I wasn't aware of that. You can still order it from me direct at escher3d.com.

    If you are using a Z probe to do Z homing, I suggest you do it at the centre of the bed.



  • As a way to test the output of the probe



  • Finaly I got it working.
    I took the Touch unter the microscope to see if there is anything with the solder connections. And there it was. A little part of the Signal wire did a short to the GND wire next to it (really no human could have seen this with his eyes). Seems like a bad soldering job. So signal pin always was pulled down to GND. Its working fine now. Thanks for the help guys 🙂
    Setting up now all the rest. How do I need to name the mesh leveling macro for G29?


  • administrators

    Unless your printer is a delta, the simplest approach is to put your gcode to deploy the probe, run G29 and retract the probe in file bed.g. Then you can use G32 or the Auto Bed Comp button to execute it.



  • @dc42:

    Unless your printer is a delta, the simplest approach is to put your gcode to deploy the probe, run G29 and retract the probe in file bed.g. Then you can use G32 or the Auto Bed Comp button to execute it.

    Just for clarification, as I've been fighting with configuring a cartesian printer using a bltouch, is the G29 going to negate the need for the z-home, or is there a simple routine to use the bltouch (or any z-probe) for z-home probing as well?


  • administrators

    You need to home the printer completely before you run G29, but you can use the Z probe to z-home. See https://duet3d.com/wiki/Configuring_RepRapFirmware_for_a_Cartesian_printer#Homing_Z_using_a_Z_probe for details, but add M401 and M402 commands around the G30 command to deploy and retract your probe.



  • Thank you, FlowerBob and DC42. This thread helped me get my printer zeroing and bed probing after digging through the wiki I don't know how many times, only to end up off in the weeds trying to figure out what I was doing wrong.

    Now, if I can only figure out how to prevent my bed sagging so far due to the overly thin material provided by the kit maker…


Locked
 

Looks like your connection to Duet3D was lost, please wait while we try to reconnect.