Jerky movements, again

  • Hello, I'm using latest release:

    Firmware Name: 	RepRapFirmware for Duet WiFi
    Firmware Electronics: 	Duet WiFi 1.0
    Firmware Version: 	1.16 (2016-11-08)
    WiFi Server Version: 	1.03 (ch fork)
    Web Interface Version: 	1.13

    And experiencing issues very close to (but not the same) that described in my old topic on reprap forums:,546995

    Circles are printed with audible clicks (also this clicks sensible then you put your finger on moving tower caret). Few clicks per second (I don't know exact value, about 3-7 per second). I hear clicks for both first layer brim/skirt and main perimeters.

    I'm using Duet WiFi beta board, 12V power supply (LED PSU, 30A), 200 steps/rev steppers and the following movement settings:

    M350 X16 Y16 Z16 E16 I1    			; Set 16x microstepping with interpolation
    M92 X100 Y100 Z100					; Set axis steps/mm
    M201 X3000 Y3000 Z3000 E3000		; Accelerations (mm/s^2)
    M203 X12000 Y12000 Z12000 E4200		; Maximum speeds (mm/min)
    M566 X600 Y600 Z600 E600		; Maximum instant speed changes mm/minute

    Maximum jerk speed does not change nothing (I have tried M566 X6000 Y6000 Z6000 E6000 also without success).

    Calibration settings at this moment is:

    M665 R105.83 L214.35 H239.30 B75.00 X-0.42 Y-0.89 Z0.00
    M666 X1.42 Y-1.13 Z-0.28

    I have tried different speeds (30-50-100 mm/second).

    M122 command output after print:

    MaxReps: 5, StepErrors: 0, MaxWait: 0ms, Underruns: 0, 0

    I have tried different slicers (Slic3r, S3D) - also without success.

    I have tried to disable heated bed (main power consumer) - without success.

    This happens with almost every circular (curved) shapes, test OpenSCAD code for model I printed:

    cylinder(r1 = 35, r2 = 20, h = 50, $fn = 1024);

    Example layer code from S3D:

    G1 X10.146 Y-32.739 Z1.700 E0.0140
    G1 X10.947 Y-32.480 Z1.701 E0.0140
    G1 X11.741 Y-32.201 Z1.701 E0.0140
    G1 X12.528 Y-31.903 Z1.702 E0.0140
    G1 X13.307 Y-31.587 Z1.702 E0.0140
    G1 X14.078 Y-31.250 Z1.702 E0.0140
    G1 X14.840 Y-30.896 Z1.703 E0.0140
    G1 X15.594 Y-30.522 Z1.703 E0.0140
    G1 X16.338 Y-30.130 Z1.704 E0.0140
    G1 X17.073 Y-29.720 Z1.704 E0.0140
    G1 X17.797 Y-29.292 Z1.704 E0.0140
    G1 X18.511 Y-28.846 Z1.705 E0.0140
    G1 X19.213 Y-28.384 Z1.705 E0.0140
    G1 X19.904 Y-27.904 Z1.705 E0.0140
    G1 X20.583 Y-27.407 Z1.706 E0.0140
    G1 X21.249 Y-26.893 Z1.706 E0.0140
    G1 X21.902 Y-26.364 Z1.707 E0.0140
    G1 X22.543 Y-25.818 Z1.707 E0.0140
    G1 X23.170 Y-25.257 Z1.707 E0.0140
    G1 X23.783 Y-24.681 Z1.708 E0.0140
    G1 X24.381 Y-24.090 Z1.708 E0.0140
    G1 X24.965 Y-23.484 Z1.709 E0.0140
    G1 X25.534 Y-22.865 Z1.709 E0.0140
    G1 X26.088 Y-22.231 Z1.709 E0.0140
    G1 X26.625 Y-21.584 Z1.710 E0.0140
    G1 X27.147 Y-20.924 Z1.710 E0.0140
    G1 X27.652 Y-20.252 Z1.711 E0.0140

    And from Slic3r:

    G1 X-34.040 Y-10.097 E0.03229
    G1 X-33.713 Y-11.138 E0.03239
    G1 X-33.282 Y-12.369 E0.03873
    G1 X-32.886 Y-13.384 E0.03235
    G1 X-32.459 Y-14.389 E0.03242
    G1 X-32.004 Y-15.376 E0.03227
    G1 X-31.516 Y-16.352 E0.03239
    G1 X-30.999 Y-17.312 E0.03237
    G1 X-30.454 Y-18.254 E0.03232
    G1 X-29.880 Y-19.179 E0.03233
    G1 X-29.278 Y-20.086 E0.03232
    G1 X-28.648 Y-20.975 E0.03237
    G1 X-27.990 Y-21.845 E0.03236
    G1 X-27.307 Y-22.693 E0.03235
    G1 X-26.599 Y-23.519 E0.03231
    G1 X-25.864 Y-24.325 E0.03237
    G1 X-25.107 Y-25.106 E0.03230
    G1 X-24.324 Y-25.865 E0.03239
    G1 X-23.519 Y-26.599 E0.03233
    G1 X-22.693 Y-27.307 E0.03232
    G1 X-21.844 Y-27.991 E0.03238
    G1 X-20.974 Y-28.648 E0.03236
    G1 X-19.908 Y-29.399 E0.03872
    G1 X-18.997 Y-29.996 E0.03234
    G1 X-18.066 Y-30.566 E0.03241
    G1 X-17.119 Y-31.106 E0.03237
    G1 X-16.157 Y-31.616 E0.03233
    G1 X-15.181 Y-32.097 E0.03231
    G1 X-14.188 Y-32.548 E0.03236
    G1 X-13.183 Y-32.967 E0.03235
    G1 X-12.167 Y-33.356 E0.03228
    G1 X-11.137 Y-33.714 E0.03240

    This is happens not only in synthetic tests but also on real models too.

    The only difference (compared to previous bug described at,546995 ) is much less visible patterns on model surface and clicks with higher frequency.

    I have seen topics about Duet jerky movements both here and on reprap forums, but not sure that this is the same issue.

    Anyone else experiencing such problems?

  • Usually I'm using this setting:

    M350 X16 Y16 Z16 E16 I1 

    I have tried today this setting:

    M350 X256 Y256 Z256 E256 I0

    Print was much quieter and without extraneous sounds and clicks. Printed part surface is also much cleaner.

    Also I have tried to change M350 settings during printing (yes, I know that I'm doing not in right way) and printer was completely freezed (I tried two times, both with the same results). DWC shows me something like "no more HTTP sessions available". The only way to restore operation was power off and power on again.


    This setting also gives quiet printing without audible clicks:

    M350 X128 Y128 Z128 E16 I0

    And then I using this setting clicks also very loud:

    M350 X8 Y8 Z8 E16 I0

  • administrators

    Thanks for the feedback I need to try to see if there is a difference between:

    M350 X16 I1 and M350 X256 I0 as they both should produce 256 microstepping.

    The M350 X8 I0 is expected to be loud as that is 8 microstepping with no interpolation.

  • 1/256 microstepping is very quiet for me, but Duet is usable only with low speeds due to high step rate.

    Also documentation isn't very clear about interpolation modes. Seems like only 1/16 microstepping mode is able to use interpolation? Or I'm not right?

  • administrators

    I have not tested with interpolation on less than 1/16 microstepping.

    What I need to test when I get a chance is the difference between 1/256 microstepping and 1/16 microstepping with interpolation because they should be the same. The interpolation should be dividing each 1/16 microstep up into 16 further microsteps.

  • No updates? Maybe I can help testing/diagnosing this issue?

  • It seems that everyone (including David and Tony) ignores me, but I still continue my research.

    I just prepared test g-code that you can run without printing something. Code just moves effector around 100 mm circle:

    G21 ; set units to millimeters
    G90 ; use absolute coordinates
    M83 ; use relative distances for extrusion
    G1 Z10.300 F4800.000
    G1 X-49.744 Y1.647 F960.000
    G1 X-49.771 Y-0.000
    G1 X-49.743 Y-1.672
    G1 X-49.659 Y-3.342
    G1 X-49.519 Y-5.009
    G1 X-49.323 Y-6.670
    G1 X-49.071 Y-8.323
    G1 X-48.763 Y-9.967
    G1 X-48.401 Y-11.599
    G1 X-47.984 Y-13.219
    G1 X-47.513 Y-14.824
    G1 X-46.988 Y-16.411
    G1 X-46.410 Y-17.981
    G1 X-45.780 Y-19.530
    G1 X-45.098 Y-21.057
    G1 X-44.365 Y-22.560
    G1 X-43.582 Y-24.038
    G1 X-42.750 Y-25.489
    G1 X-41.870 Y-26.910
    G1 X-40.928 Y-28.322
    G1 X-39.968 Y-29.661
    G1 X-38.949 Y-30.987
    G1 X-37.886 Y-32.279
    G1 X-36.781 Y-33.533
    G1 X-35.633 Y-34.750
    G1 X-34.446 Y-35.928
    G1 X-33.219 Y-37.065
    G1 X-31.956 Y-38.160
    G1 X-30.656 Y-39.212
    G1 X-29.321 Y-40.220
    G1 X-27.953 Y-41.182
    G1 X-26.554 Y-42.098
    G1 X-25.125 Y-42.966
    G1 X-23.667 Y-43.786
    G1 X-22.183 Y-44.557
    G1 X-20.674 Y-45.277
    G1 X-19.141 Y-45.946
    G1 X-17.587 Y-46.563
    G1 X-15.989 Y-47.136
    G1 X-14.420 Y-47.639
    G1 X-12.812 Y-48.097
    G1 X-11.189 Y-48.500
    G1 X-9.553 Y-48.849
    G1 X-7.907 Y-49.142
    G1 X-6.252 Y-49.380
    G1 X-4.589 Y-49.563
    G1 X-2.922 Y-49.689
    G1 X-1.251 Y-49.759
    G1 X0.447 Y-49.773
    G1 X2.093 Y-49.731
    G1 X3.763 Y-49.633 F960.000
    G1 X5.428 Y-49.479
    G1 X7.112 Y-49.264
    G1 X8.738 Y-49.003
    G1 X10.380 Y-48.681
    G1 X12.009 Y-48.305
    G1 X13.625 Y-47.875
    G1 X15.226 Y-47.390
    G1 X16.809 Y-46.852
    G1 X18.374 Y-46.261
    G1 X19.917 Y-45.618
    G1 X21.439 Y-44.923
    G1 X22.936 Y-44.178
    G1 X24.407 Y-43.382
    G1 X25.850 Y-42.538
    G1 X27.265 Y-41.646
    G1 X28.648 Y-40.707
    G1 X30.000 Y-39.721
    G1 X31.317 Y-38.691
    G1 X32.599 Y-37.617
    G1 X33.863 Y-36.484
    G1 X35.052 Y-35.344
    G1 X36.219 Y-34.146
    G1 X37.362 Y-32.891
    G1 X38.430 Y-31.637
    G1 X39.471 Y-30.329
    G1 X40.468 Y-28.986
    G1 X41.419 Y-27.610
    G1 X42.323 Y-26.203
    G1 X43.179 Y-24.767
    G1 X43.987 Y-23.302
    G1 X44.745 Y-21.812
    G1 X45.453 Y-20.296
    G1 X46.118 Y-18.735
    G1 X46.713 Y-17.199
    G1 X47.264 Y-15.620
    G1 X47.762 Y-14.023
    G1 X48.206 Y-12.411
    G1 X48.596 Y-10.785
    G1 X48.931 Y-9.146
    G1 X49.211 Y-7.497
    G1 X49.435 Y-5.840
    G1 X49.603 Y-4.176
    G1 X49.715 Y-2.508
    G1 X49.771 Y-0.836
    G1 X49.771 Y0.836
    G1 X49.715 Y2.508
    G1 X49.603 Y4.176
    G1 X49.435 Y5.840
    G1 X49.211 Y7.497
    G1 X48.931 Y9.146
    G1 X48.596 Y10.785
    G1 X48.206 Y12.411
    G1 X47.762 Y14.023
    G1 X47.264 Y15.620
    G1 X46.713 Y17.199
    G1 X46.109 Y18.758
    G1 X45.453 Y20.296
    G1 X44.745 Y21.812
    G1 X43.987 Y23.302
    G1 X43.179 Y24.767
    G1 X42.323 Y26.203
    G1 X41.419 Y27.610
    G1 X40.468 Y28.986
    G1 X39.471 Y30.329
    G1 X38.430 Y31.637
    G1 X37.346 Y32.911
    G1 X36.219 Y34.146
    G1 X35.052 Y35.344
    G1 X33.845 Y36.501
    G1 X32.599 Y37.617
    G1 X31.317 Y38.691
    G1 X30.000 Y39.721
    G1 X28.648 Y40.707
    G1 X27.265 Y41.646
    G1 X25.850 Y42.538
    G1 X24.407 Y43.382
    G1 X22.936 Y44.178
    G1 X21.439 Y44.923
    G1 X19.917 Y45.618
    G1 X18.374 Y46.261
    G1 X16.809 Y46.852
    G1 X15.226 Y47.390
    G1 X13.625 Y47.875
    G1 X12.009 Y48.305
    G1 X10.380 Y48.681
    G1 X8.714 Y49.007
    G1 X7.087 Y49.268
    G1 X5.428 Y49.479
    G1 X3.763 Y49.633
    G1 X2.093 Y49.731
    G1 X0.422 Y49.773
    G1 X-1.251 Y49.759
    G1 X-2.922 Y49.689
    G1 X-4.589 Y49.563
    G1 X-6.252 Y49.380
    G1 X-7.907 Y49.142
    G1 X-9.553 Y48.849
    G1 X-11.189 Y48.500
    G1 X-12.812 Y48.097
    G1 X-14.420 Y47.639
    G1 X-16.013 Y47.128
    G1 X-17.587 Y46.563
    G1 X-19.141 Y45.946
    G1 X-20.674 Y45.277
    G1 X-22.205 Y44.545
    G1 X-23.667 Y43.786
    G1 X-25.125 Y42.966
    G1 X-26.575 Y42.084
    G1 X-27.953 Y41.182
    G1 X-29.321 Y40.220
    G1 X-30.656 Y39.212
    G1 X-31.956 Y38.160
    G1 X-33.219 Y37.065
    G1 X-34.464 Y35.910
    G1 X-35.633 Y34.750
    G1 X-36.781 Y33.533
    G1 X-37.886 Y32.279
    G1 X-38.949 Y30.987
    G1 X-39.968 Y29.661
    G1 X-40.942 Y28.302
    G1 X-41.870 Y26.910
    G1 X-42.750 Y25.489
    G1 X-43.594 Y24.016
    G1 X-44.365 Y22.560
    G1 X-45.098 Y21.057
    G1 X-45.780 Y19.530
    G1 X-46.410 Y17.981
    G1 X-46.988 Y16.411
    G1 X-47.513 Y14.824
    G1 X-47.984 Y13.219
    G1 X-48.406 Y11.575
    G1 X-48.763 Y9.967
    G1 X-49.071 Y8.323
    G1 X-49.326 Y6.645
    G1 X-49.519 Y5.009
    G1 X-49.659 Y3.342
    G1 X-49.699 Y2.542

    This code produces jerky movements with [c]M350 X16 Y16 Z16 E16 I1[/c] command (1/16 microstepping with interpolation) and very smooth movements with [c]M350 X256 Y256 Z256 E16 I1[/c]

    I can record video to prove my words.

  • administrators

    Thanks for your example. My printers are out of action until my office refurbishment is complete, but I'll try it out when I can. Feel free to remind me on Wednesday if you don't get a response before then.

  • What happens when you do the exact same gcode with M350 X16 Y16 Z16 E16 I0 ?

  • administrators

    One other question: what motor current have you set in your M906 command?

  • @bot:

    What happens when you do the exact same gcode with M350 X16 Y16 Z16 E16 I0 ?

    The same thing, but motors are very loud in this mode (relative to interpolated I1), so clicking noise is less audible over steppers noise.


    One other question: what motor current have you set in your M906 command?

    Thank you, now I'm not alone 🙂

    I'm using [c]M906 X1500 Y1500 Z1500 E1000 I60[/c] with Wantai 42BYGHW811 motors. 200 steps/rev, 2.5A rated current, 1.8 mH phase inductance according to datasheet. Also I'm using 12V 30A LED power supply.

    I have tried also 1.9 A and 1.0 A motor current, nothing changed.

    Also I recorded both videos, my phone touches one of delta towers to amplify possible noise. I hope you can listen difference.
    UPD: click frequency on first video is about 5-10 hertz. Clicks appear while effector moves around circle. But there is no clicks while effector goes down or while straight movement (from center to start of circle).

  • Yet another video, I put my phone directly on moving caret to record better sound.

  • Seems like I need to go to Specsavers. What are we supposed to be looking at? Have you actually tried printing anything and if so, is the printed object misshapen?

  • I'm just want to say that something wrong : ) I'm not experiencing any real problems with printing using Duet WiFi, I'm happy Duet WiFi owner, but this is something abnormal.

    Yes, this clicking pattern is slightly visible on printed objects, but I'm unable take good quality photo to show this. And this almost does not affect print quality.

  • I can't see any difference in the movement between the first two videos but maybe that's because I'm an old guy who wears glasses. You seem to be trying to make videos that record the sound, so are you saying that it sounds different?

  • I ran roboduet's file on my Rostock Mx V2 and can confirm that there is a different sound as he describes. You can definitely hear a tick which might line up with the interpolation point. Both 128 and 256 microstep without interpolation are smooth and don't have the tick. There is perhaps a discontinuity at some point in the interpolation. I couldn’t hear this when running the same test on my CoreXY, so perhaps it's specific to deltas?

    However, I also ran print tests and cannot see any difference in the results! So, to me at least, this appears to be of academic interest only.

  • @deckingman:

    I can't see any difference in the movement between the first two videos but maybe that's because I'm an old guy who wears glasses. You seem to be trying to make videos that record the sound, so are you saying that it sounds different?

    Yes, that's what I want to say. English is not my native language so sometimes I cannot say what I want in few words so other people can understand me.

    Can you hear clicking (5-10 times per second) sound on last video with black picture? This clicks are felt, if I touch a finger to the carriage. This feels like tower caret stops moving for few milliseconds and then starts moving again.

    But there is no any clicks or other sounds then I change microstepping to 1/256. Everything else is the same - maximum jerk settings, accelerations, speed, motor currents and so on.

  • @lignumaqua:

    I ran roboduet's file on my Rostock Mx V2 and can confirm that there is a different sound as he describes.
    However, I also ran print tests and cannot see any difference in the results! So, to me at least, this appears to be of academic interest only.

    Thank you very much! At least this is confirmed now by other people too.

    As about differences in print quality - I can see slight differences in external surface, but I'm sure this is absolutely not a problem for me. I can try to find macro photo friendly plastic and right lighting to take photo with differences. Also I'm not sure what is affecting print quality - true 1/256 microstepping instead of interpolated 1/16 or this clicking issue.

  • administrators

    The interpolation is only completely accurate when the carriages are moving at constant speed, which is rarely the case on a delta printer. So my guess is that the clicking noises are produced when the drive gets the interpolation wrong, perhaps when a carriage reverses direction in the middle of a move. Dynamically varying microstepping will solve that, when I get round to implementing it.

  • I hear this clicking sounds with interpolation disabled at 1/16 microstepping.

    Also seems like I found bug, printer completely freezes (including ESP8266 web server code) then I executing this commands: [c]G28[/c] to home printer, [c]M350 X16 Y16 Z16 I0[/c] to disable interpolation (interpolation enabled in config) and then start printing file without (!) homing after executing M350 command. This is reproducible every time I enter this commands.


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