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    Very slight systematic waves every about 2mm on the prints

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    • droftartsundefined
      droftarts administrators @luc
      last edited by

      @luc I can't see anything obvious in your config or M122 that would be causing the issue. You could try using the latest 3.6.0-rc.2 firmware to see if it makes any difference, but I'd think the issue is either the motors as already discussed, or mechanical, ie a bad bearing on the belt run (if it affects all axes, look at the bearings not on the X carriage, as those don't move with Y axis movement). Overtightened belts can also cause issues. Finally, check that you haven't mixed up the belt and pulley types, ie running Gates GT2-2mm belts with 2GT pulleys, as the tooth profile is very slightly different.

      Ian

      Bed-slinger - Mini5+ WiFi/1LC | RRP Fisher v1 - D2 WiFi | Polargraph - D2 WiFi | TronXY X5S - 6HC/Roto | CNC router - 6HC | Tractus3D T1250 - D2 Eth

      lucundefined 1 Reply Last reply Reply Quote 0
      • lucundefined
        luc @droftarts
        last edited by luc

        @droftarts
        I don't think it could be the firmware but I'll try it last.

        All pulleys and bearings looked good but your point about doing it on all faces I could I had to check to rule out the fixed bearings not on X axis was very helpful in fact, since I had them new, I decided to change both bearings and pulleys.

        I made a test print afterwards and did not solve it so I think it is useless to disassemble the other 4 X-axis bearings.

        I only have one new motor in reserve. I don't know if it is worth doing a test by changing only one motor or is it better to do both together.

        Edit
        For GT2 or 2GT: With both old motor pulleys and belt and new ones I tried to see conme copied one over the other and I don't seem to have any doubts about that. They look okay to me.

        Edit2:
        Changed the left engine: Nothing....all the same as before!

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        • lucundefined
          luc
          last edited by luc

          hello, it seems that my problem is identified with the term VFA “Vertical Fine Artifact” and it seems strange to me that from what you read around there is no solution.

          What do you guys think about this?

          https://ellis3dp.com/Print-Tuning-Guide/articles/troubleshooting/vfas.html

          https://www.youtube.com/watch?app=desktop&v=-et5eMyLlUs

          https://www.google.com/search? q=VFAs+%28Vertical+Fine+Artifacts&client=firefox-b-d&sca_esv=cc91aa7b516a412e&ei=1egHaKX7EZCN9u8PlJz78AQ&ved=0ahUKEwjluYKEq- yMAxWQhv0HHRTOHk4Q4dUDCBE&uact=5&oq=VFAs+%28Vertical+Fine+Artifacts&gs_lp=Egxnd3Mtd2l6LXNlcnAiHVZGQXMgKFZlcnRpY2FsIEZpbmUgQXJ0aWZhY3RzMgUQIRigAUiMCVAAWABwAHgAkAEAmAGJAaABiQGqAQMwLjG4AQPIAQD4AQL4AQGYAgGgAowBmAMAkgcDMC4xoAe0AbIHAzAuMbgHjAE&sclient=gws- wiz-serp

          I have TL smoother that I used on an old printer. Can I try them on the duet 2 wifi or do I risk damaging the board?

          droftartsundefined 1 Reply Last reply Reply Quote 0
          • droftartsundefined
            droftarts administrators @luc
            last edited by

            @luc said in Very slight systematic waves every about 2mm on the prints:

            https://ellis3dp.com/Print-Tuning-Guide/articles/troubleshooting/vfas.html

            This seems like a sensible page. It focusses particularly on belt/pulley/idler teeth for ~2mm spacing VFAs. I think this is the most likely cause of your ringing, mainly because the VFAs from a 0.9 degree motor doing 160 steps per mm like yours would be much closer together. VFAs from motors usually show up between one full step and the next. On a 1.8 degree motor 80 microsteps per mm, assuming x16 microstepping, the VFAs are 0.2mm apart. On a 0.9 degree motor like yours, they'd be 0.1mm apart, which is why they are less noticeable.

            I don't know enough about the Prorifi3D motors to know if they are any good. I know Prusa spent a lot of time improving their stepper motors, and switched from 1.8 degree motors to 0.9, but still have VFA issues, even on the new Core One. Prusa introduced Phase Stepping on the Prusa XL, see https://blog.prusa3d.com/phase-stepping-how-we-busted-vibrations-and-improved-print-quality-on-the-xl-printer-with-just-a-firmware-update_94793/, but that only works with certain TMC drivers; 2240 on the Prusa XL, and 2160/5160 like on the Duet 3 6HC (though Duet have only partly enabled Phase Stepping so far).

            TL smoothers were made to address a specific design flaw in DRV8825 drivers, and helped a little for old A4998 drivers. As far as I know, they won't make any difference on TMC drivers.

            If you really want to go down the rabbit hole of looking at the stepper driver and motor, you could look at the developments in Klipper firmware. See
            https://github.com/MakerBogans/docs/wiki/TMC-Driver-Tuning
            https://github.com/andrewmcgr/klipper_tmc_autotune/tree/main

            The idea here is that the default settings of the stepper driver may not be ideal for your motor, and that you can change the stepper driver settings to better match your motor. This should work for the TMC2660 drivers on the Duet 2, but hasn't been tested. I don't actually know of anyone who has tried!

            Fortunately we don't have to install Klipper to run this; @Falcounet created an online calculator here, and @jay_s_uk made a macro that can run on a Duet, on the RRF Discord here

            Using the values for your motor from here:

            [motor_constants omc-17hm19-2004s]
            resistance: 1.45
            inductance: 0.004
            holding_torque: 0.46
            max_current: 2.0
            steps_per_revolution: 400
            

            from the online calculator we get

            pwmgrad: 6
            pwmofs: 46
            maxpwmrps: 11.087794368735375
            hstrt: 0
            hend: 1
            

            and from @jay_s_uk 's script we get

            M98 P"0:/macros/TMC tuning"
            pwmgrad = 6
            pwmofs = 46
            maxpwmrps = 11.08779
            tblank = 0.0000019
            tsd = 0.0000086
            dcoilblank = 0.0115200
            dcoilsd = 0.0125280
            hstartmin = -1
            hstrt = 1
            hend = -2
            hstrt1 = 0
            hend1 = 1
            

            The next bit is tricky, and I'm not sure if anyone has managed to get this right. If you have a Duet 3 (with TMC22xx or TMC51xx stepper drivers) you can set the stepper registers directly with M569.2. However, with the Duet 2 and TMC2660 drivers, you are limited to what can be set with the M569 F, C, B and Y parameters. And I'm not sure how those relate to the calculator's answers above. I believe the calculator answers relate to the stepper driver parameter names, so check the TMC2660 data sheet. You can also check at least some of the settings by send M569 P[driver number], eg on my Duet 3 Mini 5+ with TMC2209, I get:

            M569 P0.0
            Drive 0 runs in reverse, active low enable, timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, tpwmthrs 0 (inf mm/sec), pwmScaleSum 11, pwmScaleAuto 0, pwmOfsAuto 36, pwmGradAuto 14, pos 8
            

            NOTE: Be VERY careful messing with stepper driver registers, it's easy to destroy stepper drivers!

            Let me know if that helps.

            Ian

            Bed-slinger - Mini5+ WiFi/1LC | RRP Fisher v1 - D2 WiFi | Polargraph - D2 WiFi | TronXY X5S - 6HC/Roto | CNC router - 6HC | Tractus3D T1250 - D2 Eth

            lucundefined 1 Reply Last reply Reply Quote 2
            • lucundefined
              luc @droftarts
              last edited by luc

              @droftarts
              I thank you for the very detailed answer that took up a lot of your time for me.

              Let's go step by step:
              Cases like this, unfortunately, are dealt with by the exclusion technique. That is, you have to check the many possible causes in a way that excludes them one by one and then examine another possible cause.

              The mechanical part is the first to be checked, and from the checks done on the pulleys (4 of 8 were fitted new even though they were perfect for me) it did not produce any changes on the prints. The other four that were not replaced before were disassembled and tested by fixing them to a vise and putting them in tension with a belt and they kept swearing smooth so I think the pulleys are all ok.

              The belt was replaced. Upon disassembly the old one was not in good mechanical condition even though they looked ok to the eye. The old ones were hard to the touch, almost wooden, and if they hung down they did not stay taut but tended to curve in places.
              The new one, identical in make and model to the old one seems a bit too rubbery to me and I am waiting to receive new Gates brand 9 mm belts.

              So, I would like to try Gates belts before venturing into the driver talk, which I study in the meantime.

              In the meantime of all this, I also tried using Orca Slicer instead of Prusa Slicer and found no difference.

              Instead, I found a VFA test inside Orca Slicer setting it with speeds from 40 to 200 mm/sec and got a print where the difference of the vertical lines, even at 200mm/sec was still visible though slightly less. I mean that in the face of a very large difference in speed the lines varied very little but they were present so now I have a doubt if indeed the driver speech is the cause. That said, considering that the common and unvaried part are the non-Gates belts (even if replaced) perhaps I'd better try these before thinking about anything else.

              FYI:
              My M569 P0.0 response:
              M569 P0.0
              Drive 0 runs forwards, active low enable, timing fast, mode spreadCycle, ccr 0x101b4, toff 4, tblank 2, hstart/hend/hdec 3/3/0, pos 0

              Between yours and mine I notice the difference mode stealthChop / mode spreadCycle

              droftartsundefined 1 Reply Last reply Reply Quote 0
              • droftartsundefined
                droftarts administrators @luc
                last edited by

                @luc worn, stretched belts could cause the VFA. I think it’s worth holding off doing anything more until you fit those.

                Between yours and mine I notice the difference mode stealthChop / mode spreadCycle

                The TMC2660 drivers on the Duet 2 only support spreadcycle, no stealthChop.

                Ian

                Bed-slinger - Mini5+ WiFi/1LC | RRP Fisher v1 - D2 WiFi | Polargraph - D2 WiFi | TronXY X5S - 6HC/Roto | CNC router - 6HC | Tractus3D T1250 - D2 Eth

                lucundefined 1 Reply Last reply Reply Quote 0
                • lucundefined
                  luc @droftarts
                  last edited by

                  @droftarts said in Very slight systematic waves every about 2mm on the prints:

                  @luc worn, stretched belts could cause the VFA. I think it’s worth holding off doing anything more until you fit those.
                  Ian

                  Yes I know, but in fact that is why I replaced them. Replaced them, however, with new ones that were identical in make and model to the ones that had aged.
                  I expected some difference in the prints but instead between the old worn and hard belt and the new one I didn't notice any difference. Incredible but so it was.
                  I will try the Gates as soon as they arrive.

                  In the meantime I saw Duet 3 6HC and saw that I could use my 6 motors without expansion board (3xZ - 2 x XY + 1 Extruder) but I also noticed the price.

                  droftartsundefined 2 Replies Last reply Reply Quote 0
                  • droftartsundefined
                    droftarts administrators @luc
                    last edited by

                    @luc said in Very slight systematic waves every about 2mm on the prints:

                    I will try the Gates as soon as they arrive.

                    Ah, right, I didn't see the part where you said you had already changed the belts once. See if the Gates belts help.

                    In the meantime I saw Duet 3 6HC and saw that I could use my 6 motors without expansion board (3xZ - 2 x XY + 1 Extruder) but I also noticed the price.

                    Unfortunately, that's the cost of UK manufacture, full-compliance testing, board testing post-manufacture, hardware and firmware research and development, sales and marketing, support and documentation. Our competitors don't incur these costs, and largely rely on the community and open source competitors (like Duet3D) to provide R&D, firmware, and support.

                    Also, changing the controller board is unlikely to help with the VFAs if they are mechanical or electrical in nature.

                    Ian

                    Bed-slinger - Mini5+ WiFi/1LC | RRP Fisher v1 - D2 WiFi | Polargraph - D2 WiFi | TronXY X5S - 6HC/Roto | CNC router - 6HC | Tractus3D T1250 - D2 Eth

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                    • droftartsundefined
                      droftarts administrators @luc
                      last edited by

                      @luc Just to confirm this is definitely VFAs in the XY system, not the extruder, please watch these two videos, particularly the second one:
                      https://www.youtube.com/watch?v=dL6u0UwPJOQ
                      https://www.youtube.com/watch?v=32dTLRNIYmw

                      Print this object with your normal settings and see if you get the 'woodgrain' effect: https://mihaidesigns.com/inconsistent-extrusion/

                      If you get the woodgrain effect, then you'll know if the issue is the extruder. If the lines line up, it's something in your X and Y movement.

                      Ian

                      Bed-slinger - Mini5+ WiFi/1LC | RRP Fisher v1 - D2 WiFi | Polargraph - D2 WiFi | TronXY X5S - 6HC/Roto | CNC router - 6HC | Tractus3D T1250 - D2 Eth

                      lucundefined 1 Reply Last reply Reply Quote 0
                      • lucundefined
                        luc @droftarts
                        last edited by luc

                        @droftarts said in Very slight systematic waves every about 2mm on the prints:

                        @luc Just to confirm this is definitely VFAs in the XY system, not the extruder, please watch these two videos, particularly the second one:
                        https://www.youtube.com/watch?v=dL6u0UwPJOQ
                        https://www.youtube.com/watch?v=32dTLRNIYmw

                        Print this object with your normal settings and see if you get the 'woodgrain' effect: https://mihaidesigns.com/inconsistent-extrusion/

                        If you get the woodgrain effect, then you'll know if the issue is the extruder. If the lines line up, it's something in your X and Y movement.

                        Ian

                        Thanks for the information but I had already seen those videos and had filed down the teeth of a gear and made a printout without noticing any difference.

                        Mine is not wood grain effect.....it's really straight vertical lines...it looks just like VFA.

                        Consider that in the photo it looks like there are more stripes because of light reflections, but I assure you that the stripes are only vertical.

                        20250424_121757.jpg
                        20250424_121806.jpg

                        20250424_122728.jpg

                        tasundefined droftartsundefined 2 Replies Last reply Reply Quote 0
                        • tasundefined
                          tas @luc
                          last edited by

                          @luc
                          Hi @luc,

                          Are you using Gates pulleys as well? It is very important to have pulleys where the hole is perfectly centered and the perfect diameter. The teeth must be an exact match to the belt tooth pattern as well.

                          When you place the pulley on the motor driveshaft there should be no play. That way when you tighten the set screws they will not be able to force the pulley off-center.

                          Best of luck,

                          Tony.

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                          • droftartsundefined
                            droftarts administrators @luc
                            last edited by

                            @luc Before going through all of that, did you print a tapered object? Because the objects shown are straight. Another test; do the vertical lines always appear in exactly the same position? If you move the object over 1mm, do the lines move, or do they stay in the same place?

                            Ian

                            Bed-slinger - Mini5+ WiFi/1LC | RRP Fisher v1 - D2 WiFi | Polargraph - D2 WiFi | TronXY X5S - 6HC/Roto | CNC router - 6HC | Tractus3D T1250 - D2 Eth

                            lucundefined 1 Reply Last reply Reply Quote 0
                            • lucundefined
                              luc @droftarts
                              last edited by

                              @droftarts said in Very slight systematic waves every about 2mm on the prints:

                              @luc Before going through all of that, did you print a tapered object? Because the objects shown are straight. Another test; do the vertical lines always appear in exactly the same position? If you move the object over 1mm, do the lines move, or do they stay in the same place?

                              Ian

                              Here I am, sorry but I was at work.
                              Printed tapered object? What object could I print? Consider that I notice that effect only on flat surfaces. If I print a cylinder, the result is perfect.

                              Also consider that if you run your fingers over it, the surface is smooth. Those waves can only be seen against the light.

                              If you move the object over 1 mm, do the lines move or do they stay in the same place? I'll have to try. If I can tomorrow or as soon as I can.

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

                                @luc said in Very slight systematic waves every about 2mm on the prints:

                                What object could I print?

                                A pyramid/cone.

                                Z-Bot CoreXY Build | Thingiverse Profile

                                lucundefined 1 Reply Last reply Reply Quote 0
                                • lucundefined
                                  luc @Phaedrux
                                  last edited by

                                  @Phaedrux said in Very slight systematic waves every about 2mm on the prints:

                                  @luc said in Very slight systematic waves every about 2mm on the prints:

                                  What object could I print?

                                  A pyramid/cone.

                                  Hi, I know it is bad to leave posts like this without feedback but I have a busy and not so busy time at work. Also, I have decided to redo the whole kinematic system in a different way from the current one, and in the spare time, I have started to design and produce the prototype parts of the new system.
                                  We will catch up later.
                                  Thank you for now!

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