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    stepper precision

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    • arhiundefined
      arhi
      last edited by

      b763d0f1-891c-402c-88dc-5adbc8b982db-image.png

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      • arhiundefined
        arhi @alankilian
        last edited by

        @alankilian said in stepper precision:

        Try your open-loop vs. closed-loop experiment and hold the rotor with something for 10 steps and see how the closed-loop corrects for that once you remove the load and the open loop mode does not correct the error.

        it does correct the missed steps, but it should be also more precise than what I'm seeing 😞 ... 1° error !?!? that's more than half a step

        Anyhow done with S42B, moving on to TMC2208 driver and different motors

        fcwiltundefined 1 Reply Last reply Reply Quote 0
        • arhiundefined
          arhi
          last edited by

          Would also be cool if someone can reproduce measurements with S42B as this does not require super good/expensive/high resolution encoder, even cheap 1000 lines encoder should be able to see error 0.5° and 1°

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          • arhiundefined
            arhi
            last edited by

            54ee9d5f-b2b6-40db-b134-de6bcbfb7195-image.png

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            • fcwiltundefined
              fcwilt @arhi
              last edited by

              @arhi said in stepper precision:

              Anyhow done with S42B, moving on to TMC2208 driver and different motors

              Have you done any testing of the "two piece" closed loop systems consisting of a stepper/encoder and separate control unit?

              Thanks.

              Frederick

              Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

              arhiundefined 1 Reply Last reply Reply Quote 0
              • arhiundefined
                arhi @fcwilt
                last edited by

                @fcwilt said in stepper precision:

                Have you done any testing of the "two piece" closed loop systems consisting of a stepper/encoder and separate control unit?

                Haven't got to it yet, can't find where I put my vallder stepper with encoder and driver combo. Also I wanna finish with few nema17 before I have to use another mount to test the bigger motor

                fcwiltundefined 1 Reply Last reply Reply Quote 1
                • arhiundefined
                  arhi
                  last edited by

                  a08067b8-d637-41c5-984f-d0fcdedbe170-image.png

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                  • arhiundefined
                    arhi
                    last edited by

                    second super whooper
                    c6fd7e10-91e4-4a9b-9678-1fbbccff059a-image.png

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                    • arhiundefined
                      arhi
                      last edited by

                      third super whapper motor

                      6cd34cc0-71ff-417d-acc8-fd9df93fab06-image.png

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                      • DaBitundefined
                        DaBit
                        last edited by

                        So, basically, at 180 steps or so the actual vs demanded position deviation of the last motor is more than half a step with the others close to that, with zero load?

                        That is way worse than what I would have expected...

                        arhiundefined 1 Reply Last reply Reply Quote 0
                        • fcwiltundefined
                          fcwilt @arhi
                          last edited by

                          @arhi said in stepper precision:

                          Haven't got to it yet, can't find where I put my vallder stepper with encoder and driver combo. Also I wanna finish with few nema17 before I have to use another mount to test the bigger motor

                          That's funny.

                          A while back I purchased such a system for testing but the project got put on hold as other more important things needed to be done.

                          And now I cannot find it.

                          Frederick

                          Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

                          arhiundefined 1 Reply Last reply Reply Quote 0
                          • arhiundefined
                            arhi
                            last edited by

                            281777e7-a312-4904-a579-f2f5d7e15f95-image.png

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                            • arhiundefined
                              arhi @DaBit
                              last edited by

                              @DaBit said in stepper precision:

                              That is way worse than what I would have expected...

                              will have to spend more time looking at all this data, so far I'm running the tests and just showing the error of going forward than backwards. The other data I'm interested is spread of steps going in one direction only, how much off each step is from ideal position but I will do those graphs after I finish all the tests as I need to return this encoder in few days

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                              • arhiundefined
                                arhi @fcwilt
                                last edited by

                                @fcwilt said in stepper precision:

                                And now I cannot find it.

                                so you understand my frustration 😞
                                I'm not used to everything being "in order" and everything "having it's place" but I hate working from "storage", can't find anything, $@^%#^ is getting on my nerves and breaks my concentration too .. and I don't see the end, I doubt my house will be ready before summer 😞

                                fcwiltundefined 1 Reply Last reply Reply Quote 1
                                • arhiundefined
                                  arhi
                                  last edited by

                                  second DPM motor

                                  ce1951e4-9f5b-4d97-a971-886fa86eac28-image.png

                                  alankilianundefined 1 Reply Last reply Reply Quote 0
                                  • fcwiltundefined
                                    fcwilt @arhi
                                    last edited by

                                    @arhi

                                    I found the box with the stepper/encoder and controller!

                                    Now I just need to find the time - still looking for that.

                                    Frederick

                                    Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

                                    arhiundefined 1 Reply Last reply Reply Quote 0
                                    • arhiundefined
                                      arhi @fcwilt
                                      last edited by

                                      @fcwilt 🙂

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                                      • alankilianundefined
                                        alankilian @arhi
                                        last edited by alankilian

                                        @arhi Are you sure you're calibrating the controller every time?

                                        It looks like going forward, you get 0.5-degree of error, but going backwards, you get MUCH LESS error. Under 0.1 degree

                                        Maybe try going three turns forward and then three turns backwards just in case it take one-turn to calibrate or something.

                                        SeemeCNC Rostock Max V3 converted to V3.2 with a Duet2 Ethernet Firmware 3.2 and SE300

                                        arhiundefined 1 Reply Last reply Reply Quote 0
                                        • arhiundefined
                                          arhi @alankilian
                                          last edited by

                                          @alankilian said in stepper precision:

                                          @arhi Are you sure you're calibrating the controller every time?

                                          For S42B - yes, I am sure, I calibrated every time when running closed loop. I don't see a point as nothing physically changed in the setup between runs but I still run the calibration every time before I run the test as calibration is rather quick (it goes full circle one direction and then full circle other direction) ... anyhow notice these lasts graphs are with TMC2208, nothing to calibrate there

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                                          • arhiundefined
                                            arhi
                                            last edited by

                                            same motor as earlier only run again to see how "repeatable" this is (not very)

                                            60765527-b397-424a-b59e-087d86d938b2-image.png

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