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

    DDA & Move Debugging

    Scheduled Pinned Locked Moved Unsolved
    Firmware developers
    3
    18
    959
    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.
    • dc42undefined
      dc42 administrators @petriheino
      last edited by

      @petriheino the signal you are calling E0_EN isn't an enable signal at all, it's the SPI chip select signal to the TMC2660 driver. It goes low while the microcontroller is talking to it over SPI. Enabling and disabling a TMC2660 driver is done using SPI commands.

      The corresponding lines on the expansion bus are chip select signals when they are connected to TMC2660 drivers on a DueX expansion board, and Enable signals when they are connected to external drivers instead.

      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

      petriheinoundefined 1 Reply Last reply Reply Quote 0
      • petriheinoundefined
        petriheino @dc42
        last edited by

        @dc42
        Thats true, its also seen on the schematics.

        From TMC2660 datasheet:
        When CSN goes high, the contents of the internal shift register are latched into the internal control register

        Could this affect the motor performance negatively?

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

          @petriheino said in DDA & Move Debugging:

          Could this affect the motor performance negatively?

          No, we'd see a lot more problems if it did.

          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

          petriheinoundefined 1 Reply Last reply Reply Quote 0
          • petriheinoundefined
            petriheino @dc42
            last edited by

            @dc42
            Well there is some serious issues with retraction points, extrusion evenness, gaps in prints.
            Maybe it could be worth a try to disable this?
            Could we try it?
            Is there some 10kHz SPI loop to the driver that could be disabled?
            (I can compile custom FW if needed)

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

              @petriheino that isn't a solution to your issue. The TMC drivers are designed to operate with SPI transactions. Just think of the problems there would be with axis motion if SPI comms affected movement of the motors.

              I suggest you post photos of your prints to show what extrusion issues you are having. Try with pressure advance disabled initially in case excessive PA is part of the problem. Also make sure you don't have coast to end or pressure adjustment enabled in the slicer. And tell us what extruder you are using and what its steps/mm is.

              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

              petriheinoundefined 3 Replies Last reply Reply Quote 0
              • petriheinoundefined
                petriheino @dc42
                last edited by

                @dc42

                If you believe its a issue related to settings / extruder, then please send info about recommended setup or what type of extruder are you using to test. I can mount any type of extruder in that case and repeat the tests.

                Now its running on direct extruder, 143steps/mm in 16x microstepping. It was made to 256x because RRF is failing to keep position of extruder, tested with test script as below

                M350 X16 Y16 Z16 I1		; Microstepping X Y Z
                M350 E256 I0			; Microstepping E
                M92 X80.00 Y80.00 Z400.0 E2210.000; set steps per mm
                

                12 - Test E max Acceleration.gcode

                With this test, mount indicator on rotor, and check if it returns to starting position. RRF fails if using absolute mode, but relative extrusion works, as long as theres enough steps/mm.

                The maximum for my extruder (safe values, it can do also approx 30% more):

                M566 E3000		;instantaneous speed change / Jerk (mm/min)
                M203 E6000		;max speeds (mm/min)
                M201 E9000		;accelerations (mm/s^2)
                

                Print error is that, theres always gaps in the print, and very rough retraction points and wavy walls, and gaps in solid infills.

                1 Reply Last reply Reply Quote 0
                • petriheinoundefined
                  petriheino @dc42
                  last edited by

                  @dc42
                  Some pictures
                  P8 closeup.jpg P8 hole calibration piece.jpeg

                  1 Reply Last reply Reply Quote 0
                  • petriheinoundefined
                    petriheino @dc42
                    last edited by petriheino

                    @dc42 Mismatching step amounts measured with logic analyzer

                    Note: in pictures there is signal 1&2 AS5040 encoder (10-bit quadrature A&B)
                    Signal 3: E0 DIR. Signal 4: E0 STEP. Signal 5: Not connected. Signal 6: E0 CS.

                    Retraction event, reverses 699 steps

                    Retraction.png

                    Un-rectraction event, 656 steps

                    Un-retraction.png

                    Start of printing

                    0-100ms.png

                    This is with M572 D0 S0.06 and M207 S0.30 F1200 Z0.1. It is very fine tuned setting, and print error is much worse if using bigger retraction distance.

                    Here is comparison how it takes time to recover after un-retraction. at 699 steps there should be finally filament back at nozzle, but we have already lost several tens of microseconds of printing.

                    end vs start.png

                    RRF v 3.3.

                    botundefined 1 Reply Last reply Reply Quote 0
                    • botundefined
                      bot @petriheino
                      last edited by

                      @petriheino try decreasing your extruder M566 significantly.

                      Pressure advance works with E jerk (m566, instantaneous speed change). If your E jerk is set way too high, your stepper motor might be acting funny.

                      Try M566 E240, or even 120.

                      *not actually a robot

                      petriheinoundefined 2 Replies Last reply Reply Quote 0
                      • petriheinoundefined
                        petriheino @bot
                        last edited by

                        @bot
                        Previous post done with M566:
                        Maximum jerk rates (mm/min): X: 300.0, Y: 300.0, Z: 600.0, E: 3000.0, jerk policy: 1. It resulted in 699 retraction steps and 656 un-retraction steps

                        I went ahead and re-captured with M566 E120 but it seems to make the problem worse, by resulting in 713 retraction steps, making problem worse (not affecting un-retraction.) Signal seems same, and motor sound is same (one 2A motor stand-alone on table)

                        1 Reply Last reply Reply Quote 1
                        • petriheinoundefined
                          petriheino @bot
                          last edited by

                          @bot
                          By disabling Pressure Advance, retract and un-retract steps are matching, 662 and 662.

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