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    Stall detection on Z still not working!

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    • deckingmanundefined
      deckingman
      last edited by

      https://duet3d.dozuki.com/Wiki/Stall_detection_and_sensorless_homing

      Ian
      https://somei3deas.wordpress.com/
      https://www.youtube.com/@deckingman

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      • GaRv3undefined
        GaRv3
        last edited by

        The problem is that stall detection obviously only works when printing gcode files. If I want to use it for homing, it has to work using the DWC as well.
        Is there a setting to change this behaviour or is this coming in one of the next releases?

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        • Phaedruxundefined
          Phaedrux Moderator
          last edited by

          What do you mean? It works when homing in the DWC as well.

          What I've found though is that the sensitivity of the detection seems to vary quite a bit depending on the position of the axis and the temperature of the motors. For instance it Triggers more when higher on the axis where there is more friction on my lead screws. So the behaviour can seem inconsistent and settings that work at one point stop working when conditions change.

          I'd put this feature under the heading of, yes it works but you probably shouldn't rely on it unless you have to.

          Z-Bot CoreXY Build | Thingiverse Profile

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          • Phaedruxundefined
            Phaedrux Moderator
            last edited by

            There are no correct settings someone can provide for you even knowing the motor specs. It will take a lot of testing to narrow down a working configuration.

            I can tell what worked for me as an example and the reasoning for it but you'll have to test out different values to see what works in your system.

            Jerk 1, acceleration 10, speed 200, sensitivity 3, trigger value 200, current 40% of 2000

            Changing any of those values even slightly was enough to make it either too sensitive or not sensitive enough.

            Z-Bot CoreXY Build | Thingiverse Profile

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            • GaRv3undefined
              GaRv3
              last edited by

              Whenever I start a print, I get stall warnings during the homing process.
              If I start the homing by clicking on the button in DWC, I do not get these warnings.

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              • Phaedruxundefined
                Phaedrux Moderator
                last edited by

                That's interesting. I can't think of why that would be.

                Z-Bot CoreXY Build | Thingiverse Profile

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                • GaRv3undefined
                  GaRv3
                  last edited by

                  Well, but that's the way it is. 100% reproducible.

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                  • Phaedruxundefined
                    Phaedrux Moderator
                    last edited by

                    Can you post your homing files?

                    Z-Bot CoreXY Build | Thingiverse Profile

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                    • GaRv3undefined
                      GaRv3
                      last edited by GaRv3

                      This is the code used to home:

                      ; homeall.g
                      ; called to home all axes
                      ;
                      ; generated by RepRapFirmware Configuration Tool on Fri Feb 02 2018 20:19:38 GMT+0100
                      G91 ; relative positioning
                      G1 S2 Z5 F6000 ; lift Z relative to current position
                      G1 S1 X-235 Y-230 F1800 ; move quickly to X or Y endstop and stop there (first pass)
                      ;G1 S1 X-235 ; home X axis
                      ;G1 S1 Y-235 ; home Y axis
                      G1 X5 Y5 F6000 ; go back a few mm
                      G1 S1 X-235 F360 ; move slowly to X axis endstop once more (second pass)
                      G1 S1 Y-235 F360 ; then move slowly to Y axis endstop
                      G1 S1 Z-255 F1800 ; move Z down stopping at the endstop

                      M564 H0 S0 ; Allow moving unhomed axes
                      M906 Z5 ; Set Z motor current to some mA
                      G1 S0 V-10 ; Move Z down with little force to even the axis out
                      M18 Z ; Disable the stepper motors for Z
                      G4 S0.1 ; Wait 0.1 second
                      M906 Z900 ; Set Z motor current back to 900mA
                      M564 H1 S1 ; prevent unhomed axes from moving

                      G90 ; absolute positioning
                      G92 Z0 U0 V0 ; zero position for Z, U(Z1) and V(Z2)

                      G1 Z10 F1800 ; uncomment this line to 0lift the nozzle after homing

                      dc42undefined 1 Reply Last reply Reply Quote 0
                      • dc42undefined
                        dc42 administrators @GaRv3
                        last edited by

                        @garv3 said in Stall detection on Z still not working!:

                        M906 Z5 ; Set Z motor current to some mA
                        G1 S0 V-10 ; Move Z down with little force to even the axis out
                        M18 Z ; Disable the stepper motors for Z

                        I presume you have warn-on-motor-stall enabled. You are deliberately stalling the Z motor in that move. You could use M915 V R0 to disable warning on stall detect before that move, and M915 V R1 afterwards.

                        Duet WiFi hardware designer and firmware engineer
                        Please do not ask me for Duet support via PM or email, use the forum
                        http://www.escher3d.com, https://miscsolutions.wordpress.com

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                        • GaRv3undefined
                          GaRv3
                          last edited by

                          The problem is not that I get the warning. I want the warning to pop up. The problem is that I get the warning only when printing gcode files. I want it to pop up when using DWC too. Otherwise using stall detection for homing will not work for DWC.

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                          • dc42undefined
                            dc42 administrators
                            last edited by

                            You don't need to have warnings pop up when using stall detection for homing; although having warnings appear may help while you are tuning the stall detection threshold.

                            Warning messages that are not associated with a particular command should appear on all input devices. If they are not appearing in DWC, maybe this is connected with your DWC user interface settings. Have you checked whether they are shown on the GCode Console page of DWC?

                            Duet WiFi hardware designer and firmware engineer
                            Please do not ask me for Duet support via PM or email, use the forum
                            http://www.escher3d.com, https://miscsolutions.wordpress.com

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                            • GaRv3undefined
                              GaRv3
                              last edited by GaRv3

                              I know the messages are not necessary for the homeng after tuning but I need them to tune the detection and therefore I want to use them.
                              They do not appear in the console when using DWC to home. When printing a file, they pop up and are logged in the console.
                              Additionally I cannot be sure stall detection will work if I do not get messages. I cannot try it before I know it works.

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                              • dc42undefined
                                dc42 administrators
                                last edited by

                                The easiest way of getting warning that I can think of is to put the commands you want to test in a GCode file and print it. However, when I was testing stall detection endstops, I didn't find any need to do this. If the stall detection is working then the homing move stops when the tower or axis reaches the hard stop. If it tries to keep going, then stall detection isn't working. You should use reduced current when homing with stall detection anyway, to make sure that the motor does stall instead of the belt jumping on the pulley.

                                Duet WiFi hardware designer and firmware engineer
                                Please do not ask me for Duet support via PM or email, use the forum
                                http://www.escher3d.com, https://miscsolutions.wordpress.com

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