UNSOLVED Problem with calibrating magnetic filement sensor



  • Hi
    I just installed a magnetic filement sensor, version 1.7a.
    Wiring and start up was no problem.
    But when I try to calibrate I get numbers that are not realistic.
    Spent 3 hours searching the forum for answers but no one seems to had the same issue.

    So what happens is
    I start a print and I get the message

    "Extruder 0 reports too little movement"

    Run the M591 D0 command and get

    M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 24.80mm/rev, allow 70% to 130%, check every 50.0mm, version 3, mag 130 agc 114, measured sensitivity 117529.14mm/rev, min 100% max 100% over 114.8mm.

    The measuring sensitivity varies between 4000mm/rev to 100 000 mm/rev¨
    which ovbviously can´t be right

    I put the sensor on the Z sensor input (using probe for Z) but according to the documentation that should work.

    I changed the measuring length to 50 mm to see if the issue was not enough length.

    Printing a cube with 60 mm side so the printer is not doing any retraction.

    Mag and agc values are not great from what I read but should not give such values.

    config
    M591 D0 P3 C2 S1 R70:130 L24.8 E50 ; Duet3D rotating magnet sensor for extruder drive 0 is connected to E0 endstop input, enabled, sensitivity 24.8mm.rev, 70% to 130% tolerance, 3mm detection length

    Firmware Name: RepRapFirmware for Duet 2 WiFi/Ethernet
    Firmware Electronics: Duet WiFi 1.02 or later
    Firmware Version: 2.05 (2019-12-13b1)


  • Moderator

    The AGC seems a bit high. Are the mating surfaces of the case smooth allowing for a tight fit together? If the fit isn't great that might explain it.



  • I sanded it down after first post. Now agc is 103. But still have issues

    20:23:45M591 D0
    Printing paused at X225.7 Y192.1 Z0.8
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 80.00mm/rev, allow 1% to 3000%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 61.14mm/rev, min 0% max 242% over 99.4mm
    20:23:36Resume state saved
    20:23:33M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 80.00mm/rev, allow 1% to 3000%, check every 5.0mm, version 3, mag 132 agc 103, measured sensitivity 55.43mm/rev, min 1% max 219% over 57.6mm
    20:23:27M24
    Printing resumed
    20:22:43M591 D0
    Printing paused at X225.0 Y193.9 Z0.8
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 80.00mm/rev, allow 1% to 3000%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 196.10mm/rev, min 0% max 325% over 38.1mm

    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 80.00mm/rev, allow 1% to 3000%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 196.10mm/rev, min 0% max 325% over 38.1mm
    20:22:32Resume state saved
    20:22:30M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 80.00mm/rev, allow 1% to 3000%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 60.26mm/rev, min 100% max 100% over 11.5mm



  • @Phaedrux
    I just rebooted the printer and tried again. Got numbers that looked good.
    Changed the config to these values.

    Ran a print
    I got about 10 min in before it stopped.

    I copied the results from M591 D0.
    It is kind of long. I clicked update to see what was going on.
    UPDATE. I had to shorten post to be able to submit

    20:42:34M591 D0
    Printing paused at X228.3 Y188.9 Z3.2
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.30mm/rev, min 15% max 104% over 3290.0mm
    20:42:25Resume state saved
    20:42:11M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.24mm/rev, min 91% max 104% over 3103.4mm
    20:42:10M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.24mm/rev, min 91% max 104% over 3092.3mm
    20:42:08M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.23mm/rev, min 91% max 104% over 3065.8mm
    20:42:07M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.23mm/rev, min 91% max 104% over 3050.2mm
    20:42:02M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.22mm/rev, min 91% max 104% over 2986.2mm
    20:42:01M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 130 agc 103, measured sensitivity 26.22mm/rev, min 91% max 104% over 2965.4mm
    20:41:47M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 26.19mm/rev, min 91% max 104% over 2799.7mm
    20:41:46M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 26.19mm/rev, min 91% max 104% over 2788.6mm
    20:41:26M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 26.16mm/rev, min 91% max 104% over 2510.1mm
    20:41:19M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 26.13mm/rev, min 90% max 104% over 2388.1mm
    20:41:06M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 75% to 125%, check every 5.0mm, version 3, mag 131 agc 103, measured sensitivity 26.06mm/rev, min 90% max 103% over 2163.7mm
    20:41:04M591 D0


  • Moderator

    @Frankzz said in Problem with calibrating magnetic filement sensor:

    I sanded it down after first post. Now agc is 103. But still have issues

    That's promising. Can you sand it further?



  • I did. Now agc is 86-82
    I see that measured sensitivity still goes up during print.
    It started with
    14:15:59M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 132 agc 84, measured sensitivity 26.65mm/rev, min 96% max 106% over 160.7mm

    After 40 min printing it started to go down. It is fine for what I am doing. If it would kept rising it would be a problem. Have a Modix 120X. 2 weeks for a print is not common but it happens. The sensor will fix the problems I had before.
    Here is the read out in the end of print

    14:53:42M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 131 agc 82, measured sensitivity 29.32mm/rev, min 22% max 117% over 31084.6mm
    14:51:24M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 130 agc 82, measured sensitivity 29.45mm/rev, min 22% max 117% over 29104.8mm
    14:49:12M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 130 agc 82, measured sensitivity 29.49mm/rev, min 22% max 117% over 27375.1mm
    14:46:19M591 D0
    Duet3D magnetic filament monitor on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 132 agc 82, measured sensitivity 29.50mm/rev, min 22% max 117% over 24965.7mm


  • Moderator

    So it seems to be functioning better now? Keep us posted.



  • @Phaedrux
    Yes it is working. Don´t like that the sensitivity changes. Will see how it works on a larger print.
    I do have question though. I have read everything I can find on the forum but no answer.

    My magnetic sensor is very close to the extruder. It means when the filement runs out it is not sticking up from the extruder when runing just the magnetic sensor.
    So I planned to use the standard filement run-out sensor (microswitch).
    I changed the P from 3 to 4 but it just says "no filement present"
    So I figured the sensor (microswitch) needed to be reversed (NO vs NC) and modified the sensor.
    It did not help.
    I did some testing with both NC and NO to make sure it has nothing to do with wiring.

    The microswitch is connected to E0 stop and the magnet sensor to Z stop.

    Reading on the forum I found a post implicit suggesting that both should be connected to the same I/O.
    It does not make sense. Then there would be no need to have 5 pins on the magnetic sensor.
    But how does the Duet know which input is which when using magnetic sensor AND micro switch? (P4)
    Can you please clarify?

    Frank


  • Moderator

    When are where was the sensor purchased? Perhaps to save any further frustration with testing etc we should try exchanging it in case the issues is the sensor itself.



  • @Phaedrux
    I bought it in the beginning of July from hobby store in Poland. Simply because they had it in stock.
    I can live with the sensitivity slipping as long as it does not mean that it goes out of tolerance.
    To check this I need to run a larger print which I was about to today once I solved the run out switch problem.

    But I would like to know the answer to the micro switch question.

    Just to clarify, the micro switch I am using worked fine before I changed the config file to accommodate the magnetic sensor.

    When writing this I think I figured out the problem. I am 99% sure that I erased the line configuring the micro switch.
    Will test this tomorrow.



  • Ok I put the M591 line defining simple microswitch runut sensor (like it was prior to magnetic sensor) and kept the M591 line for the magnetic sensor.

    It did not work.

    So question still stands. How to wire the runout sensor to make this work?

    Maybe this should be separate thread. Tell me and I will repost it.

    Frank



  • Ok now I figured it out.
    It is kind of obvious that the microswitch is to be connected to the magnetic switch.
    I thought it should still be connected to the Duet board.
    Could not figure out why the magnetic switch had the 2 pins, that is what solved it.
    Now I only need to route 4 more meters of cable and find the connectors.
    Frank


  • Moderator

    Glad you got it figured out.



  • @Phaedrux
    Yes, I did the wiring yesterday, did some testing and started a 60 hour print.
    It worked for about an hour then it started saying "too little movement"
    I have set the tolerance to 10%-125%, just as stated before.

    But there are no problems, no clog and filament extrudes fine when doing it manually at highest speed.
    I tried to make it work for 2 hours. In the end I got sensitivity value in the 1000 and it would not work at all.
    I tried it this morning with the same result.

    So I actually think there is something wrong with the sensor.
    So yes, I would like a replacement sensor.
    Frank


  • administrators

    [EDITED] I suspect that the reason for the small sensitivity changes is that the average print speed is changing and your extruder suffers from nonlinear extrusion, i.e. the steps/mm goes up a little as the extrusion rate increases.

    When the sensitivity gets very high (you mentioned 1000), does the AGC still read in the 80 to 90 region?



  • @dc42
    AGC is 76-78. Now the sensor is not working at all.
    I can´t post the respons from printer since I am at work. Will do that later today.

    The problem just escalated until it stopped completely.
    When printer pauses I can extrude manually with highest speed. Then I resume and it just went shorter and shorter distance until it paused again.
    I the end it pause direct but I see it extruding.

    So right now I like to try a new sensor.

    Frank



  • Here is the last numbers when the sensor still kind of worked
    00:49:42M591 D0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 131 agc 76, measured sensitivity 29.46mm/rev, min 26% max 112% over 407.0mm
    00:49:28M591 D0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 131 agc 76, measured sensitivity 28.48mm/rev, min 60% max 108% over 307.8mm
    00:48:54M591 D0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 131 agc 76, measured sensitivity 27.06mm/rev, min 97% max 102% over 102.0mm
    00:48:47M591 D0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 131 agc 76, measured sensitivity 27.00mm/rev, min 97% max 102% over 61.4mm



  • Here is the read out last night when it just gave up
    00:58:28M591 D0
    Printing paused at X744.9 Y222.7 Z6.0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 130 agc 76, measured sensitivity 17063.90mm/rev, min 100% max 100% over 16.7mm

    I just tried again. First it just stopped more or less direct.
    18:01:03M591 D0
    Printing paused at X424.3 Y225.9 Z6.0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 129 agc 76, measured sensitivity infmm/rev, min 0% max 0% over 14.4mm

    Guessing it is not spinning so I pulled the filament and tested so the sensor rotor moved. It did.

    Resumed again and got this far
    18:04:43M591 D0
    Printing paused at X135.5 Y298.0 Z6.0
    Duet3D magnetic filament monitor with switch on input 2, enabled, sensitivity 25.58mm/rev, allow 10% to 125%, check every 5.0mm, version 3, mag 132 agc 78, measured sensitivity 28.65mm/rev, min 1% max 110% over 108.8mm.

    Can you please give advise what to do?

    Frank


  • administrators

    Hi Frank, I authorise a replacement sensor for you under warranty. Please contact your supplier and refer them to this forum post for authorization.



  • @dc42
    Ok will do.
    I just stopped the print, deleted the M591 line in config and will try to resurrect the print with out sensor
    If that works it is definently the sensor



  • Now it is printing fine. It will not tell me if it stops extruding but I can find the height and use resurrect.

    But just when the print started I got this message on webinterface

    Connection Lost
    The connection between the browser and your machine has been interrupted.

    Reason: Unknown (SyntaxError: Unexpected token , in JSON at position 845)

    Please reload the web interface to proceed.

    Tried to reload, restart computer and restart router. Nothing helped.
    Don´t want to restart printer in mid print.
    Is this a known issue?



  • Got similar problem. AGC - 122. I ended up sanding resin case and the magnet sensing IC. Now agc is 56 and all problems solved.



  • @BoA
    I started out with AGC 114. (See previous posts)
    AGC now is around 80 and that is well within specs.

    It did work fine for a while and that tells me the issue is the sensor.
    But If the next sensor does the same I will try to this one more to see if it helps.
    Does anyone know the lower tolerence of AGC ?

    Frank


  • Moderator

    @Frankzz said in Problem with calibrating magnetic filement sensor:

    Connection Lost
    The connection between the browser and your machine has been interrupted.
    Reason: Unknown (SyntaxError: Unexpected token , in JSON at position 845)
    Please reload the web interface to proceed.

    What version of firmware and DWC are you running? There may be a version mismatch.

    Currently supported versions are FW 2.05.1 and DWC 2.0.7 and FW 3.1.1 and DWC 3.1.1



  • @Phaedrux
    The web interface has worked fine for 8 weeks when I upgraded the printer to Duet.
    This happened right when I resumed a print. Have a hard time believing it has something to do with versions.

    I switched off and on the wifi module in Duet and for some reason it had change the address.
    Used the address the came up in the display and now it works again.


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