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

Indirect (bearing) laser filament monitor concept

Scheduled Pinned Locked Moved
Filament Monitor
26
109
14.1k
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.
  • undefined
    Adrian52
    last edited by 27 Jun 2019, 21:39

    I have been continuing to play with the monitor, and have also made a version for 10mm bearings - I have put it on thingiverse, 3717158. I have made the jaws part spring loaded, so that you can adjust the tension gripping the filament.
    When printing slowly, the maximum and minimum values are very accurate (within 2-5%, as above). With faster extrusion, the range tends to get bigger. Using longer measuring intervals seems to give less variation - I am currently using 10mm. Using the A1 switch seem to give a very accurate measure of the total filament used - sometimes giving uncanny agreement with the value reported by DWC (my last print the monitor reported 1640mm, DWC 1639mm, and the slicer said 1643mm). When I use the A0 switch, the monitor reports 85-90% of the filament usage reported by DWC. The total usage data seems to remain extremely accurate when printing faster, where the maximum and minimum values become very wide. Could the max/min variation be due to hitting limits of processing the data?

    1 Reply Last reply Reply Quote 1
    • undefined
      dc42 administrators
      last edited by dc42 29 Jun 2019, 09:52

      It could be that the synchronisation in firmware between the filament sensor reading and the extrusion commanded isn't always working properly.

      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

      undefined 1 Reply Last reply 3 Jul 2019, 20:44 Reply Quote 1
      • undefined
        Adrian52 @dc42
        last edited by 3 Jul 2019, 20:44

        @dc42 have done some more tests using a 20x20x4mm cube with 100%fill, printed at 60mm /sec, then varying the layer height or width to achieve specific filament movement rates. I print the first layer at 10mm/sec, so checking after 100 mm gives a 'slow' baseline for each test, and the total is a little over 700mm. Under these conditions I have no hiccups or missed steps.
        For me, the monitor works well with filament movements up to 1.3mm/sec (max/min within 10% of the average) , but for 1.5mm/sec and 2mm/sec, the max/min range becomes very wide, often going negative on the min side. I get similar results with and without a 5mm spacer, although the actual numbers are higher with the spacer as previously observed.
        The total extrusion reported by the monitor is very close (usually within 1%) to that shown by dwc or the slicer, even when the extrusion rate is above 1.5mm /sec.
        I have also started to note the error rates for the monitor reported by M122. For tests below 1.3mm/sec, frame errors are 2000-4000, and pol errors high(20000-30000). Above 1.3mm/sec, frame errors are 20000 - 30000, but pol errors are below 10000. I have also noticed that the error count is not zeroed when you start a new print - I have been doing a reset after each test to zero things up.

        undefined undefined 2 Replies Last reply 4 Jul 2019, 02:23 Reply Quote 2
        • undefined
          zapta
          last edited by 4 Jul 2019, 01:42

          @adrian52, what is that you are trying to achieve? If it's the detection of filament grinding, do you need exact measurements or just no movement in a certain time period?

          1 Reply Last reply Reply Quote 0
          • undefined
            brunofporto @Adrian52
            last edited by brunofporto 7 Apr 2019, 02:25 4 Jul 2019, 02:23

            @adrian52 What is curious is that I had similar results (high precision with total measured length compared to predicted by slicer) with direct filament readings!!! It was precise enough that I could even calibrate extrusion steps/mm with it. Even with filaments that I had horrible max and min results.

            1 Reply Last reply Reply Quote 0
            • undefined
              dc42 administrators @Adrian52
              last edited by 4 Jul 2019, 08:48

              @adrian52 said in Indirect (bearing) laser filament monitor concept:

              I have also started to note the error rates for the monitor reported by M122. For tests below 1.3mm/sec, frame errors are 2000-4000, and pol errors high(20000-30000). Above 1.3mm/sec, frame errors are 20000 - 30000, but pol errors are below 10000.

              Hmm, that sounds odd. Which firmware version are you running? Run M115 to make sure. Also, which revision Duet do you have? We changed the values of the filtering capacitors on later ones to help the filament monitor signals get through more reliably.

              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

              undefined 1 Reply Last reply 4 Jul 2019, 09:09 Reply Quote 0
              • undefined
                Adrian52 @dc42
                last edited by 4 Jul 2019, 09:09

                @dc42 running 2.03+1. I have a 1.01 duet wifi. Is there a way I can improve the situation?

                undefined 1 Reply Last reply 4 Jul 2019, 10:22 Reply Quote 0
                • undefined
                  dc42 administrators @Adrian52
                  last edited by dc42 7 Apr 2019, 10:23 4 Jul 2019, 10:22

                  You could try connecting the filament monitor to one of the endstop inputs on CONN_LCD, which have no filter capacitors. That would be easier than removing the filter capacitor from a regular endstop input on the Duet. But if the problem is interference from a stepper motor cable, it may make matters worse.

                  Keep the cable to the filament monitor away from the extruder motor cable; or if they must run together, try using shielded cable for the filament monitor.

                  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

                  undefined 1 Reply Last reply 4 Jul 2019, 16:59 Reply Quote 1
                  • undefined
                    Adrian52 @dc42
                    last edited by 4 Jul 2019, 16:59

                    @dc42 Excellent advice. I have connected to stop 10 on conn_lcd using shielded cable (a repurposed USB cable that also has a ferrite ring), and the errors are now zero. I have got up to 3mm/second filament (0.5 width, 0.3 height at 60mm/sec) and the max/min were 107%/95% of the average. Wow.

                    undefined undefined 2 Replies Last reply 9 Aug 2020, 02:02 Reply Quote 1
                    • undefined
                      taglia @Crash69
                      last edited by 26 Aug 2019, 03:49

                      @crash69 Thank you for this; I really like your design (it printed like a charm)! Also, your .scad file is straightforward to tweak. I have changed the following:

                      • Added a bracket to attach to my Ender 3 with a SeeMeCNC EZR Struder;
                      • Increased the sensor distance to 19mm (thanks @Adrian52 for the analysis);
                      • Made the split on the bearing mounts longer, to make it easier to slide the bearings in;
                      • Adapted the bearing size to some bearing I had lying around (16x8x5).

                      I did a quick test with a shorter sensor distance; the results were much better than with direct reading, but I still got a wide range. In the next few days, I will print another one with all the changes listed above. If anybody is interested, I can publish the remix.

                      Thank you all for this very informative thread.

                      undefined 1 Reply Last reply 30 Aug 2019, 11:40 Reply Quote 0
                      • undefined
                        brunofporto @taglia
                        last edited by 30 Aug 2019, 11:40

                        @taglia Please do publish! 😄

                        undefined 1 Reply Last reply 8 Sept 2019, 09:25 Reply Quote 1
                        • undefined
                          taglia @brunofporto
                          last edited by 8 Sept 2019, 09:25

                          @brunofporto Apologies for the long silence, it took me a while to get to some good results. I have now managed to print for a couple of days with consistent results and no sudden pauses. The sensor also saved a big part that I was printing (no more filament).

                          The cause of my problems was the filament sliding on the bearing, and this caused negative reads. I have found this product at a local shop, sprayed two layers on my bearings, and the sensor seems now stable, even at high speed. I have also increased the pressure a bit and reprinted the mount with black eSun PLA+, which appears to be stronger than regular PLA.

                          This is the model that I am currently using. I was too lazy to remodel the attachment to the extruder, which I had already designed in Fusion 360: this is the STL imported by the OpenSCAD file.

                          These are the bearings.

                          1 Reply Last reply Reply Quote 0
                          • undefined
                            3dmntbighker
                            last edited by 3dmntbighker 12 Sept 2019, 00:41 8 Dec 2019, 09:30

                            Anybody determine the optimized number for "E" with an indirect bearing setup? I see someone using E5, but I get no data with E5. E4 seems to work.

                            Duet3D laser filament monitor v1 on input 3, disabled, allow 10% to 75%, check every 4.0mm, version 1, measured min 17% avg 30% max 47% over 246.5mm

                            Duet3D laser filament monitor v1 on input 3, enabled, allow 10% to 70%, check every 4.0mm, version 1, measured min 14% avg 29% max 54% over 2218.6mm

                            BTW, what is different about the version 2 sensor? Or is it a firmware difference?

                            Scratch built CoreXY with Maestro
                            Heavily modified Ender 3 with Maestro
                            MPCNC work in progress with Duet WiFi

                            1 Reply Last reply Reply Quote 0
                            • undefined
                              danzaywer
                              last edited by danzaywer 2 Jun 2020, 16:38 6 Feb 2020, 16:33

                              @Crash69 said in Indirect (bearing) laser filament monitor concept:

                              5x10x4 (mr105)

                              Hi everyone, I just published my interpretation for a Duet3D laser filament monitor enclosure. Use a rubber band and have moving parts.
                              https://www.thingiverse.com/thing:4147811
                              render1.png

                              1 Reply Last reply Reply Quote 2
                              • undefined
                                radekzl
                                last edited by 5 Apr 2020, 20:27

                                Thank you very much for your idea. I do little improvement on bearings I put there black heat shrink tube. Between bearings and heat shrink tube I put chemoprene glue and everythink works fine. Surface is black and scanning is stable:

                                Duet3D laser filament monitor v1 on input 4, enabled, allow 15% to 250%, check every 6.0mm, version 1, measured min 154% avg 166% max 174% over 6397.2mm

                                This values are stable for all materials which I tested yet.

                                1 Reply Last reply Reply Quote 0
                                • cabal2000undefined
                                  cabal2000 @brunofporto
                                  last edited by 3 Aug 2020, 17:44

                                  @brunofporto said in Indirect (bearing) laser filament monitor concept:

                                  F623ZZ

                                  Love this design, did you redesign for F623ZZ or will the present config work?

                                  1 Reply Last reply Reply Quote 0
                                  • undefined
                                    mitch
                                    last edited by mitch 8 Sept 2020, 01:34 9 Aug 2020, 00:55

                                    An interesting remix is out there as well.
                                    https://www.thingiverse.com/thing:4341389

                                    I found most of the parts on amazon but it can get a bit spendy. I would like to see the roller pulley as a micro switch so it could be used as a static filament sensor for startup and filament change macros.

                                    Carbon Fiber Rod 5mm
                                    https://amzn.to/3agj6Mc

                                    U604 Bearing
                                    https://amzn.to/2PE3Wa4

                                    MR95ZZ Bearing x 2
                                    https://amzn.to/3fJYTPM

                                    Embedded Bowden Coupling for Metal for E3D heatsink x 1
                                    https://amzn.to/3akDv2N

                                    Belt Tensioner Spring
                                    https://amzn.to/3ijLIqD

                                    Extruder PUlly 36T
                                    https://amzn.to/31N5rsf

                                    M3 Insert Brass Nut
                                    https://amzn.to/3kqOkEO

                                    undefined 1 Reply Last reply 10 Aug 2020, 00:41 Reply Quote 0
                                    • undefined
                                      mitch @Adrian52
                                      last edited by 9 Aug 2020, 02:02

                                      @Adrian52 said in Indirect (bearing) laser filament monitor concept:

                                      @dc42 Excellent advice. I have connected to stop 10 on conn_lcd using shielded cable (a repurposed USB cable that also has a ferrite ring), and the errors are now zero. I have got up to 3mm/second filament (0.5 width, 0.3 height at 60mm/sec) and the max/min were 107%/95% of the average. Wow.

                                      @Adrian52 , Are you saying that by using the direct filament (stock so to speak) enclosure you are getting zero errors now that you have a shielded cable running from your sensor to the board? I am debating on attempting your indirect enclosure concept but if you had success by making a wiring modification perhaps that is a better way to fix this.

                                      Also, Any chance you would want to factor in a roller micro switch into your mod so that the sensor can be used as a static filament present sensor as well?

                                      undefined 1 Reply Last reply 10 Aug 2020, 09:06 Reply Quote 0
                                      • undefined
                                        JADoglio @mitch
                                        last edited by 10 Aug 2020, 00:41

                                        @mitch

                                        This is a really good design. Have you built one and tested it yet? Thanks

                                        1 Reply Last reply Reply Quote 0
                                        • undefined
                                          mitch
                                          last edited by mitch 8 Oct 2020, 02:20 10 Aug 2020, 02:19

                                          I am attempting to print the enclosure for it now. I could prob build a few because I will have a few left over parts. Parts are still on order. I am curious if a carbon tube would work instead of the rod. The design seems to show some notches cut so I went with the solid rod.

                                          1 Reply Last reply Reply Quote 0
                                          • First post
                                            Last post
                                          Unless otherwise noted, all forum content is licensed under CC-BY-SA