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    Mesh grid compensation - Setup on Initial Gcode

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    • FelixHundefined
      FelixH @Phaedrux
      last edited by

      @Phaedrux said in Mesh grid compensation - Setup on Initial Gcode:

      @FelixH said in Mesh grid compensation - Setup on Initial Gcode:

      Error: Z probe already triggered at start of probing move

      That's odd. Does the switch signal need to be inverted?

      I tried to invert it with the expected result: crash onto the bed. I followed all the articles I could possibly find and I'm pretty sure the probe is well connected. When is is deployed (aka connected) the light on the board is lit and the Z prove value on the web interface is 0. When I press the switch, the value ramps up to 1000 and the led is off...

      I'm really running out of thing to try

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      • Phaedruxundefined
        Phaedrux Moderator
        last edited by Phaedrux

        G28 ; home all axes
        
        M291 P"Attach probe" R"Warning" S3   ; warning message
        
        G1 Z15.  ; go close to to the surface
        G30        ; Z=0 datum thing
        G1 Z75    ; go up a bit
        M291 P"Remove probe" R"Warning" S3   ; warning message
        
        G28; home again, in case the effector move by the removal of the probe
        
        G29 S1  ;use mesh grid to compensate
        G92 E0
        G1 F1200 E10
        G92 E0
        

        I had written up a long post with a few things to test, but then I saw something that I think is the cause of the problem.

        If you look at your start gcode, you home the towers, attach the probe, probe the bed, and then home the towers again, resetting the z datum, and then load the heightmap.

        Remove the second G28. In fact, also remove the G29 S1 for now, since I don't trust the heightmap. If your homed height is correct, and the probe is accurate, and your initial delta calibration is good, you should at least be able to reliably get Z0 to touch the bed as it should at the same spot you probe the bed at.

        If that works, re run the G29 to generate a new map after you've done another G30 at the center of the bed, but DON'T home the towers between that G30 and the G29.

        Z-Bot CoreXY Build | Thingiverse Profile

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        • FelixHundefined
          FelixH
          last edited by

          this is something that I added this afternoon. But I will try you suggestion anyway. However, when I do a G1 Z0 for instance, the nozzle goes to a nice bed distance, but the print fails because no map is loaded...
          I'll try your approach, however.

          Phaedruxundefined 1 Reply Last reply Reply Quote 0
          • FelixHundefined
            FelixH
            last edited by

            Screenshot_2020-02-01 Kossel(1).png

            I did the G30, and G29 S1 and tried it again without a second G28... nothing.

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            • Phaedruxundefined
              Phaedrux Moderator @FelixH
              last edited by

              @FelixH alright. The gist of my alternate approach if this doesn't prove fruitful was to test using m558 P0 to use manual probing as a control experiment.

              Z-Bot CoreXY Build | Thingiverse Profile

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              • FelixHundefined
                FelixH
                last edited by FelixH

                yeah, I think that's the next step. Just for the sake of it I tried to use the Stall Detection as probe (P10) but it didn't work...

                Phaedruxundefined 1 Reply Last reply Reply Quote 0
                • Phaedruxundefined
                  Phaedrux Moderator @FelixH
                  last edited by

                  @FelixH said in Mesh grid compensation - Setup on Initial Gcode:

                  Stall Detection as probe

                  Yeah that would be fundamentally impossible on a delta I think.

                  Z-Bot CoreXY Build | Thingiverse Profile

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                  • FelixHundefined
                    FelixH @Phaedrux
                    last edited by FelixH

                    @Phaedrux said in Mesh grid compensation - Setup on Initial Gcode:

                    @FelixH alright. The gist of my alternate approach if this doesn't prove fruitful was to test using m558 P0 to use manual probing as a control experiment.

                    well, just tried that and it worked without errors. As it should.

                    Not only that, but I am also printing the model it gave everything away. At least I have confirmation that the problem was not reading the bed map.

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                    • Phaedruxundefined
                      Phaedrux Moderator
                      last edited by

                      So the probe is working for the height map creation with g29 but not for just setting the z0 with g30?

                      Z-Bot CoreXY Build | Thingiverse Profile

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                      • FelixHundefined
                        FelixH
                        last edited by

                        It appears so. Although when I send G30 followed by a G29 S1 from the console, no error or warning appears on the screen

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                        • Phaedruxundefined
                          Phaedrux Moderator @FelixH
                          last edited by

                          @FelixH that's good. That's as it should be. Does that include g30 with the probe or manual?

                          Z-Bot CoreXY Build | Thingiverse Profile

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                          • FelixHundefined
                            FelixH
                            last edited by

                            with the probe. If I do it outside of a print, it's not a problem. If I do it within the initial code of the print, then I get the warnings, i.e. that the probe was already triggered at the beginning of the probing. Yesterday I recimped the terminals of the probe. Everything is sound

                            infiniteloopundefined 1 Reply Last reply Reply Quote 0
                            • infiniteloopundefined
                              infiniteloop @FelixH
                              last edited by

                              @FelixH said in Mesh grid compensation - Setup on Initial Gcode:

                              If I do it within the initial code of the print, then I get the warnings…

                              Looks to me as if the slicer commands the head to Z=0 before your G30 is executed in the initial section. As a test, you might insert a G0 Z4.0 (or whatever height is appropriate for your probe to keep free from the bed) just above the G30.

                              Phaedruxundefined 1 Reply Last reply Reply Quote 1
                              • Phaedruxundefined
                                Phaedrux Moderator @infiniteloop
                                last edited by

                                @infiniteloop said in Mesh grid compensation - Setup on Initial Gcode:

                                @FelixH said in Mesh grid compensation - Setup on Initial Gcode:

                                If I do it within the initial code of the print, then I get the warnings…

                                Looks to me as if the slicer commands the head to Z=0 before your G30 is executed in the initial section. As a test, you might insert a G0 Z4.0 (or whatever height is appropriate for your probe to keep free from the bed) just above the G30.

                                It would appear he's got it at 15mm above the bed. and the probe offset is 12mm.

                                G1 Z15.  ; go close to to the surface
                                G30        ; Z=0 datum thing
                                G1 Z75    ; go up a bit
                                

                                But maybe it should be higher still incase the homed height is off? 25mm maybe?

                                Z-Bot CoreXY Build | Thingiverse Profile

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                                • infiniteloopundefined
                                  infiniteloop @Phaedrux
                                  last edited by

                                  @Phaedrux said in Mesh grid compensation - Setup on Initial Gcode:

                                  It would appear he's got it at 15mm above the bed. and the probe offset is 12mm.

                                  That’s absolutely fine, but: I had a similar problem with Cura when trying to set the extruder to relative movements - Cura tends to put some own lyrics in front of the user-defined intro, depending on settings and prefs. That’s why I propose a quick test - else, we should have a look at the first lines of Gcode from the slicer.

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                                  • FelixHundefined
                                    FelixH @Phaedrux
                                    last edited by

                                    @Phaedrux said in Mesh grid compensation - Setup on Initial Gcode:

                                    It would appear he's got it at 15mm above the bed. and the probe offset is 12mm.

                                    G1 Z15.  ; go close to to the surface
                                    G30        ; Z=0 datum thing
                                    G1 Z75    ; go up a bit
                                    

                                    But maybe it should be higher still incase the homed height is off? 25mm maybe?

                                    well, damn it!

                                    ladies and gentlemen, we can close this thread as the error has been found.

                                    The G1 Z15 command was implemented in order to control the speed while diving down. Apparently it didn't occur to me that the probe offset is 16.10mm. So the probe effectively was triggered before the G30 command was event queued. I just did a test run with a G1 Z25 instead and, voilà... it worked... I swear I never noticed the probe touching before the G30 command...

                                    Thank you all for your brainstorming and patience!

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                                    • Phaedruxundefined
                                      Phaedrux Moderator
                                      last edited by

                                      @infiniteloop 👍

                                      Glad you got it sorted out finally.

                                      Z-Bot CoreXY Build | Thingiverse Profile

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                                      • infiniteloopundefined
                                        infiniteloop @Phaedrux
                                        last edited by

                                        @Phaedrux said in Mesh grid compensation - Setup on Initial Gcode:

                                        Glad you got it sorted out finally.

                                        Just jumped in when you had narrowed down the cause to a single question: if G30 works stand-alone, what is different when it resides in a .gcode file? So the honours belong to you, Sherlock 🤓

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                                        • FelixHundefined
                                          FelixH @infiniteloop
                                          last edited by

                                          @infiniteloop said in Mesh grid compensation - Setup on Initial Gcode:

                                          @Phaedrux said in Mesh grid compensation - Setup on Initial Gcode:

                                          Glad you got it sorted out finally.

                                          Just jumped in when you had narrowed down the cause to a single question: if G30 works stand-alone, what is different when it resides in a .gcode file? So the honours belong to you, Sherlock 🤓

                                          I coudn't agree more. It was not my doing at all...

                                          infiniteloopundefined 1 Reply Last reply Reply Quote 0
                                          • infiniteloopundefined
                                            infiniteloop @FelixH
                                            last edited by

                                            @FelixH said in Mesh grid compensation - Setup on Initial Gcode:

                                            It was not my doing at all...

                                            Sorry, but I disagree. Looking at those (rare) dudes who boldly claim to never ever having made anything wrong, thus always suspecting others to be the sole cause of their mishap, I have to appreciate that you instead tried to understand what’s going wrong, throughout the whole thread. Finally, it was you who put the loose ends together and spotted the gcode fragment in question. I think @Phaedrux won’t object if I state that it is fun to work with guys like you.

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