Duet3D Logo Duet3D
    • Tags
    • Documentation
    • Order
    • Register
    • Login

    BL Touch Mesh bed correction not working since minor rebuild

    Scheduled Pinned Locked Moved
    Tuning and tweaking
    5
    37
    5.3k
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • number40fanundefined
      number40fan
      last edited by

      G1 Z30
      G1 Z5
      G1 Z30
      G4 S2
      G1 Z5
      G1 Z30
      G4 S2
      G1 Z5
      G1 Z30
      G4 S2
      G1 Z5
      G1 Z30
      G4 S2
      G1 Z5
      G1 Z30
      G4 S2
      G1 Z5
      G1 Z30
      G4 S2
      G1 Z5

      Here will give you 2 seconds on the table test.

      1 Reply Last reply Reply Quote 0
      • shogranundefined
        shogran
        last edited by

        @number40fan:

        If you want to increase the time, just change the S*. That is in seconds or you can change it complete to P**** and run it in milliseconds.

        Well damn. It's not the probe. Thank-you for coming up with that test because it's very likely I wouldn't have ever considered it. Got hung up on the probe being off.

        For some reason my bed is lowering an extra ~2mm when moving down and not when going up. Not enough holding torque?

        I'm running a three leadscrew system powered by one hefty NEMA17 with 2:1 gearing.

        1 Reply Last reply Reply Quote 0
        • number40fanundefined
          number40fan
          last edited by

          Has to be torque. One more test. Lower your Z speed down to almost nothing. I see it is already low, but go lower. Run the last thing I posted while watching for anything that might not be doing what it is supposed too.

          1 Reply Last reply Reply Quote 0
          • shogranundefined
            shogran
            last edited by

            @number40fan:

            Has to be torque. One more test. Lower your Z speed down to almost nothing. I see it is already low, but go lower. Run the last thing I posted while watching for anything that might not be doing what it is supposed too.

            I've just had to power down, up early for work in the morning.

            I'll run it slow first chance I get tomorrow and let you know what it does.

            Many thanks again!

            1 Reply Last reply Reply Quote 0
            • number40fanundefined
              number40fan
              last edited by

              No problem. While I am thinking about it though, if you still don't see any looseness and since the last thing you did was replace a lead screw…take that one back out and flip it over and test again. Maybe, it is rougher on one side versus the other. Rough coming down, no biggy because you have gravity helping.

              1 Reply Last reply Reply Quote 0
              • shogranundefined
                shogran
                last edited by

                @number40fan:

                No problem. While I am thinking about it though, if you still don't see any looseness and since the last thing you did was replace a lead screw…take that one back out and flip it over and test again. Maybe, it is rougher on one side versus the other. Rough coming down, no biggy because you have gravity helping.

                There's still some wiggle room in the amps being given to the Z motor so I'll play with that a little bit. Thinking about it, because of the CoreXY design, whenever I measure bed movement to check steps/mm; I measure it lowering and it always seems to move correctly unless the downward motion follows an upward motion as we discovered last night

                Is there any significance there? Perhaps acceleration or jerk could be moving it too quickly in the opposite direction?

                1 Reply Last reply Reply Quote 0
                • number40fanundefined
                  number40fan
                  last edited by

                  Your M566 Z is already pretty low, as well as your M201 and M203, but I would adjust them lower just for testing purposes. Could always put the G4 between each move so that it has time to settle to see if that makes a difference. Are you running 1.8° or .9° motors? Commenting out the M350 might be something to try too.

                  I would think if you were to adjust your steps/mm for your up movement, you'd end up with a larger drop. Need to get both directions moving the same amount first, then adjust the steps to make it correct. You should be able to determine your steps needed by the degree of motor using, pitch of your lead screws, pitch of belt and pulley tooth count and your gearing.

                  1 Reply Last reply Reply Quote 0
                  • shogranundefined
                    shogran
                    last edited by

                    Escaping the office in 2 hours, will try those things first.

                    All motors are 1.8°. In theory my steps/mm are correct based on calculations using those variables. Just using that as an example of a time when the bed moves in the downwards direction without dropping.

                    1 Reply Last reply Reply Quote 0
                    • shogranundefined
                      shogran
                      last edited by

                      Okay, I ran the same macro as is with all those settings turned right down and M350 commented out. Unfortunately no fix.

                      Reset the settings and bumped Z motor amps up to 2.0 from 1.8. No better.

                      I then ran with a 2 second gap between every command and this did not work.

                      If I command the Z +10 then -10 via the web control buttons, it moves up 10 and down 10. No problems. I noticed this uses G91 before the movements would this be making a difference?

                      EDIT: It appears to be struggling on the move ups intermittently using the web controls. This leads me to believe the problem is not with the bed lowering too far, but raising it enough. I'm going to take the screws off and re-assemble

                      1 Reply Last reply Reply Quote 0
                      • number40fanundefined
                        number40fan
                        last edited by

                        Glad to hear you are on the right direction now.

                        The G91 are just moves, where as the G1 are locations.

                        1 Reply Last reply Reply Quote 0
                        • shogranundefined
                          shogran
                          last edited by

                          So it's not perfect but, it's an improvement!

                          0.533 0.533 0.519 0.501 0.527 results from probing the same point.

                          Thanks all for your patience and feedback. You've been awesome!

                          1 Reply Last reply Reply Quote 0
                          • T3P3Tonyundefined
                            T3P3Tony administrators
                            last edited by

                            G91 sets it to relative positioning which makes sense for the web control as its +/- the value from where ever it is now. It is normal to set back to absolute positioning (G90) for normal operation as gcode files produced by slicers use absolute positioning as a default

                            www.duet3d.com

                            1 Reply Last reply Reply Quote 0
                            • number40fanundefined
                              number40fan
                              last edited by

                              That does look better. Were your M566 and M102/3 still low when running those tests or did you put them back to where they were?

                              1 Reply Last reply Reply Quote 0
                              • shogranundefined
                                shogran
                                last edited by

                                That's with everything put back. Going to tune it all in properly and get a mesh compensation run once I have it a bit tighter

                                1 Reply Last reply Reply Quote 0
                                • First post
                                  Last post
                                Unless otherwise noted, all forum content is licensed under CC-BY-SA