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    Prusa upgraded to duet, weird extrusion

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    • Murloc992undefined
      Murloc992 @NitroFreak
      last edited by

      @NitroFreak said in Prusa upgraded to duet, weird extrusion:

      I dont think its the belts as otherwise the artifacts would be vertical and not on an angle, and definitely not changing with the size of the cube...
      Did you go through the prusa thread about the 0.9 degree steppers yet?

      Not yet, it's a large post. I hope to do it today maybe.

      Just not sure what else to try at the moment. I could try using a bearing idler to be honest, just to see if I get some kind of wobble from the idling and the noise is just a placebo kind of thing.

      "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

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      • droftartsundefined
        droftarts administrators
        last edited by

        Looking back, are your e steps per mm 276 still? I think they should be around 410 for BMG with 1.8 degree motors, and higher for 0.9. This might mean the filament isn’t running in the hobbed part of the gear. This would force the two hobbed shafts further apart, far enough for the gears on the shafts to mesh poorly, and give poor extrusion. Is there any chance you’ve assembled the extruder incorrectly? Feel free to post pictures!

        Swapping out the extruder drive for your old one might also me an option, if it fits the Bear setup.

        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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        • Vetiundefined
          Veti
          last edited by

          @droftarts said in Prusa upgraded to duet, weird extrusion:

          Looking back, are your e steps per mm 276 still? I think they should be around 410 for BMG with 1.8 degree motors,

          its a prusa. so no 3:1 reduction. thats just the normal around 100 something increased by the 0.9 stepper.

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

            @Veti Ah yes, of course. Might still be strange meshing of the two filament drive gears, though.

            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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            • Murloc992undefined
              Murloc992
              last edited by

              @Veti said in Prusa upgraded to duet, weird extrusion:

              @droftarts said in Prusa upgraded to duet, weird extrusion:

              Looking back, are your e steps per mm 276 still? I think they should be around 410 for BMG with 1.8 degree motors,
              

              its a prusa. so no 3:1 reduction. thats just the normal around 100 something increased by the 0.9 stepper.

              If to be completely accurate: 133 default, 138 after calibration with 1.8' motor. 276 with 0.9' motor. Steps are spot on. 😄

              @droftarts said in Prusa upgraded to duet, weird extrusion:

              Is there any chance you’ve assembled the extruder incorrectly? Feel free to post pictures!

              Not a chance. I've owned this printer for several(3+) years by now. Went through MK2.5S, MK2.5X(custom), MK3 "hybrid"(adapted for 2.5), bear extruder. Never assembled it wrong. 😄

              Here's how my filament is going through the main bondtech gear:
              2019-12-21 16.50.28.jpg

              @droftarts said in Prusa upgraded to duet, weird extrusion:

              @Veti Ah yes, of course. Might still be strange meshing of the two filament drive gears, though.

              Ian

              Meshing seems fine, but I will try putting in 623 bearing idler after I customize it.

              "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

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              • NitroFreakundefined
                NitroFreak
                last edited by

                I know what it might be. In the Prusa bear thread they talked about how the 0.9 might not have enough torque to direct drive the extruder.

                I just read that you‘re using the 12v PS.
                0.9 degree steppers really want 24v otherwise you will not be able to reach good speeds and torque, because you literally only have half the torque vs 24v and torque is further halved because you have the 0.9 instead of a 1.8 stepper. I could imagine the extruder is lacking until it reaches the next full step where it snaps to, resulting in this sort of extrusion inconsistency.

                I would suggest you try a 24v power supply

                Murloc992undefined 1 Reply Last reply Reply Quote 0
                • Murloc992undefined
                  Murloc992 @NitroFreak
                  last edited by Murloc992

                  @NitroFreak said in Prusa upgraded to duet, weird extrusion:

                  I know what it might be. In the Prusa bear thread they talked about how the 0.9 might not have enough torque to direct drive the extruder.

                  I just read that you‘re using the 12v PS.
                  0.9 degree steppers really want 24v otherwise you will not be able to reach good speeds and torque, because you literally only have half the torque vs 24v and torque is further halved because you have the 0.9 instead of a 1.8 stepper. I could imagine the extruder is lacking until it reaches the next full step where it snaps to, resulting in this sort of extrusion inconsistency.

                  I would suggest you try a 24v power supply

                  I actually once pushed filament out at 60mm/s, 100mm of it. Nothing skipped. The speed of the extruder wheel spooked me quite a lot though. 😆

                  Yeah, sounds good, but I have 12V bed, 12V heater, 12V fans, etc..

                  "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

                  NitroFreakundefined 1 Reply Last reply Reply Quote 0
                  • Vetiundefined
                    Veti
                    last edited by

                    did you try the original 1.8 stepper again? you initially wanted to get rid of the vfa, which only need the swap of the x and y stepper.

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                    • NitroFreakundefined
                      NitroFreak @Murloc992
                      last edited by

                      @Murloc992 said in Prusa upgraded to duet, weird extrusion:

                      @NitroFreak said in Prusa upgraded to duet, weird extrusion:

                      I know what it might be. In the Prusa bear thread they talked about how the 0.9 might not have enough torque to direct drive the extruder.

                      I just read that you‘re using the 12v PS.
                      0.9 degree steppers really want 24v otherwise you will not be able to reach good speeds and torque, because you literally only have half the torque vs 24v and torque is further halved because you have the 0.9 instead of a 1.8 stepper. I could imagine the extruder is lacking until it reaches the next full step where it snaps to, resulting in this sort of extrusion inconsistency.

                      I would suggest you try a 24v power supply

                      I actually once pushed filament out at 60mm/s, 100mm of it. Nothing skipped. The speed of the extruder wheel spooked me quite a lot though. 😆

                      Yeah, sounds good, but I have 12V bed, 12V heater, 12V fans, etc..

                      i doubt it was pushed out at 60mm/s , even my volcano with a BMG grinds filament after 12mm/s filament speed. Maybe you mean print speed? or mm/min?
                      If you do not want to convert to 24v, i suggest your best bet would be to put the 1.8 degree stepper back in or use a 3:1 gearing

                      Murloc992undefined 1 Reply Last reply Reply Quote 0
                      • droftartsundefined
                        droftarts administrators
                        last edited by

                        Fair enough re assembly, just running out of ideas! @NitroFreak isn’t quite right about torque of 0.9 motors (see https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors#Section_Step_angle ) except at high speed, but the extruder doesn’t turn that fast. Powering with 24V would be a better option for 0.9 degree motors, though.

                        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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                        • Murloc992undefined
                          Murloc992 @NitroFreak
                          last edited by

                          @NitroFreak said in Prusa upgraded to duet, weird extrusion:

                          @Murloc992 said in Prusa upgraded to duet, weird extrusion:

                          @NitroFreak said in Prusa upgraded to duet, weird extrusion:

                          I know what it might be. In the Prusa bear thread they talked about how the 0.9 might not have enough torque to direct drive the extruder.

                          I just read that you‘re using the 12v PS.
                          0.9 degree steppers really want 24v otherwise you will not be able to reach good speeds and torque, because you literally only have half the torque vs 24v and torque is further halved because you have the 0.9 instead of a 1.8 stepper. I could imagine the extruder is lacking until it reaches the next full step where it snaps to, resulting in this sort of extrusion inconsistency.

                          I would suggest you try a 24v power supply

                          I actually once pushed filament out at 60mm/s, 100mm of it. Nothing skipped. The speed of the extruder wheel spooked me quite a lot though. 😆

                          Yeah, sounds good, but I have 12V bed, 12V heater, 12V fans, etc..

                          i doubt it was pushed out at 60mm/s , even my volcano with a BMG grinds filament after 12mm/s filament speed. Maybe you mean print speed? or mm/min?
                          If you do not want to convert to 24v, i suggest your best bet would be to put the 1.8 degree stepper back in or use a 3:1 gearing

                          Maybe the motor skipped and I didn't hear it? I can try putting the original motor back in, but it also was pulsing, just less.

                          Like that:
                          893547f2-e561-4a16-9a31-96ffc2a1148d-image.png

                          "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

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                          • droftartsundefined
                            droftarts administrators
                            last edited by

                            How about the other way around; maybe you have the idler overtightened and the BMG gears are meshing badly because they’re too tight?!

                            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

                            Murloc992undefined 1 Reply Last reply Reply Quote 0
                            • Murloc992undefined
                              Murloc992 @droftarts
                              last edited by

                              @droftarts said in Prusa upgraded to duet, weird extrusion:

                              How about the other way around; maybe you have the idler overtightened and the BMG gears are meshing badly because they’re too tight?!

                              Ian

                              I have tried the "correct tension" method: so that it just grabs with minimal tension and ofc overtightening, no difference. BUT I have an idea. Let me check.

                              "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

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                              • Murloc992undefined
                                Murloc992
                                last edited by

                                Nevermind.. I tried limiting the side-to-side play bondtech idler has, even played with currents throughout the layers and nothing seemed to give any effect. I went from original 1200mA, to 1400, 1600, then tried going lower, 1000, 800, 600, 400. It never skipped, the print looks identical. The print is a very slow single wall cube print. 15 minutes for 25x25x25mm.

                                "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

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                                • Murloc992undefined
                                  Murloc992
                                  last edited by

                                  Fun fact: if I extrude using the web control at 5mm/s, there's no pulsing. If I extrude at 15mm/s (no skipping till 4 in a row, must be heat related) it's extremely smooth. If I extrude at 1mm/s, it pulses INSANELY.

                                  "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

                                  droftartsundefined 1 Reply Last reply Reply Quote 0
                                  • NitroFreakundefined
                                    NitroFreak
                                    last edited by

                                    thats because of the firmware minimum speed of 1.5mm/s iirc?

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

                                      @NitroFreak said in Prusa upgraded to duet, weird extrusion:

                                      thats because of the firmware minimum speed of 1.5mm/s iirc?

                                      It’s 0.5mm/s. from Gcode dictionary in G1 definition:

                                      For CNC users especially: RRF has a default minimum movement speed of 0.5mm/sec. In firmware 2.03 and later this can be changed using the I ('i') parameter of the M203 command.

                                      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 @Murloc992
                                        last edited by

                                        @Murloc992 not sure when Back EMF kicks in? See https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors#Section_Back_emf_due_to_rotation

                                        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

                                        Murloc992undefined 1 Reply Last reply Reply Quote 0
                                        • Murloc992undefined
                                          Murloc992 @droftarts
                                          last edited by

                                          @droftarts said in Prusa upgraded to duet, weird extrusion:

                                          @Murloc992 not sure when Back EMF kicks in? See https://duet3d.dozuki.com/Wiki/Choosing_and_connecting_stepper_motors#Section_Back_emf_due_to_rotation

                                          Ian

                                          Not sure...

                                          Would toying around with CHOPCONF values help here?

                                          "Prusa Bear" : Full Bear frame, Bear X-Axis and Extruder. Duet 2 WiFi with RRF 3.2.2.

                                          Vetiundefined 1 Reply Last reply Reply Quote 0
                                          • Vetiundefined
                                            Veti @Murloc992
                                            last edited by

                                            @Murloc992 said in Prusa upgraded to duet, weird extrusion:

                                            Would toying around with CHOPCONF values help here?

                                            no but increasing voltage helps

                                            Murloc992undefined 1 Reply Last reply Reply Quote 0
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