Laser Filament Monitor



  • So...
    current pos 9.6, brightness 83, shutter 17, measured min -3% avg 62% max 1833% over 3761.8mm

    the color of the PLA is somewhat of a shiny transparent green... describing it, not the name...

    I had to turn off this feature to see where it calibrated as the print kept stopping...

    Do those numbers seem a little out of place?
    Can I enable the monitor to only stop the print IF there is no or zero movement for set mm, and not be influenced by the range I have set? I am asking only for plastic I have that has this problem, and wouldn't want to leave it like that all the time as I would always want to know if there is a slow/jam whenever I can actually use that feature.


  • administrators

    @bluedust The monitor does not like that PLA, or at least your enclosure. do you have any other PLA to check with as I and other testers have generally done OK with PLA, most of the problematic filament has been PETG.



  • So far this is the only PLA that gave me negative and 1k%+ max numbers.
    PETG worked out OK, but was around 80% to 120%.
    Most PLAs I have played with so far run between 10% and 80% but put the monitored mm to 4 to narrow it down a lot more (was at 3).
    I currently have it set to 6, but do not remember why and could have been an accident/typo. But still, this role of PLA is driving me a bit nuts.
    I swapped it out for another color green I have used this sensor on previously just to complete the print, and it appears to be doing the same thing. Print stopped a few times outside of low and max numbers.
    Set it off for now to see where it gets too.
    I knew this thing would be a little trouble to get the settings down so I am not complaining at all. I had a PETG print that took over 60 hours and ran out of plastic around 56/58 hours. This little thing saved me. Saved a handful of prints so far I was worried about printing because the roles were getting low, and this is allowing me to use up the last little bit of 4 or 5 roles so far.

    I think I have had it installed about 3+ weeks now, maybe 150/200 hours printing with it. Just saying if it's not the PLA, I really don't think it is the case I printed for it, but possibly some debris inside. Will check it after this print or beforehand if it keeps stopping.

    So far this sensor is been well worth the cost (and the wait in my case, ordered it Nov/Dec of last year). I am very happy Duet3d decided to sell it even though they knew the issues upfront people may have with it (and gave us fair warning 👍 ). I just has so much trouble with jams and lost prints shortly after building this printer where my extruder would chew up the plastic when there were a lot of retractions. I needed this. Now my main issue is running out of plastic on longer prints/low spools.

    I have printed a few different enclosures for this thing, but this is the one I ended up using.
    https://www.thingiverse.com/thing:3219410

    If you have any advice, or a good lessons learned post on the Laser Filament Sensor, I would be happy to read it.

    Thanks!



  • Where do you get the values? I installed a laser filament sensor and enabled it. It seems to be working as printing stops sometimes reporting too little movement of the extruder and I have to manually resume printing. From the doku I can't figure out how this is supposed to work. I wish the Duet guys would bother to explain in more detail how one uses this when new to Duet.



  • I just used the documentation to set it up. It was missing one critical comment (I think this was fixed), but after reading the whole page I figured out what that one needed item was.

    Page is here.
    https://duet3d.dozuki.com/Wiki/Duet3dFilamentMonitor_LaserVersion

    Read the above page for what each settings means.

    For my understanding, and keeping this as simple as possible.... Not including the hardware setup...

    Step 1.
    Put this code in your config file.
    M591 D0 P5 C3 R40:120 E3.0 S0
    M591 D0

    I don't know why the extra "M591 D0", but I try to follow the directions.

    Step 2.
    Check the every every 5 or 10 minutes with this command.
    M591 D0

    Duet3D laser filament monitor on input 3, disabled, allow 40% to 120%, check every 3.0mm, current pos 1.4, brightness 92, shutter 17, measured min 92% avg 98% max 152% over 181.8mm

    Step 3.
    It will display the low, average, and high numbers.

    After the low and high numbers seem to stay consistent for awhile, update the R values to be just outside of those values.
    For my example from Step 2. R could be...

    R85:110
    And you could put this in your config to enable those settings to stop the print if the laser say motion outside of those ranges.

    M591 D0 P5 C3 R85:110 E3.0 S1

    Wash/Rinse/Repeat
    If the print stops, before you hit resume, Run the following again to see where laser saw it go out of the set ranges and change the R value again accordingly.

    M591 D0

    The E Value can also be tweaked to help calibrate that. I have played with it a little bit if the ranges I was getting was really far apart. I believe it is the distance in mm that the laser will check the speed before coming up with a % R value. Also, once you start the printer, it can take a 100 mm + before it comes up up with a calibrated number to start working from. The longer you let it run, the better the calibrated numbers you will get to put in the config.

    Oh, and if this wasn't understood from the reading/link above. Someone please correct me if I am wrong, but the % is the perceived speed difference from what the printer says it is trying to move the filament into the extruder to what the speed the laser is reading it is actually moving. The problem is the laser isn't always able to see the actual movement well because of the different types of plastic and colors so the numbers can be way off and hence the calibration per spool of plastic type and color. Works best with PLA, but I have printed with PETG, Steel PLA, Wood PLA, and will be playing with TPE later this week.

    Let me know if this helps answer your questions. I still feel like a noob around here, but still do try to help.



  • I just copied this out of my printer as I am currently trying to calibrate it for this role of plastic. you can see the changes to the Min Avg and Max over time. Once they settle, I will update my R %:% values and change the S0 to S1 to enable it.

    M591 D0
    Duet3D laser filament monitor on input 3, disabled, allow 10% to 120%, check every 6.0mm, current pos 2.3, brightness 91, shutter 17, measured min 31% avg 96% max 152% over 1574.8mm
    3/24/2019, 10:12:26 AM M591 D0
    Duet3D laser filament monitor on input 3, disabled, allow 10% to 120%, check every 6.0mm, current pos -6.7, brightness 87, shutter 17, measured min 64% avg 96% max 149% over 932.6mm
    3/24/2019, 10:06:32 AM M591 D0
    Duet3D laser filament monitor on input 3, disabled, allow 10% to 120%, check every 6.0mm, current pos 2.5, brightness 83, shutter 17, measured min 64% avg 96% max 137% over 793.1mm
    3/24/2019, 9:58:40 AM M591 D0
    Duet3D laser filament monitor on input 3, disabled, allow 10% to 120%, check every 6.0mm, current pos -5.6, brightness 91, shutter 17, measured min 64% avg 96% max 137% over 659.8mm
    3/24/2019, 9:54:14 AM M591 D0
    Duet3D laser filament monitor on input 3, disabled, allow 10% to 120%, check every 6.0mm, current pos 8.0, brightness 93, shutter 17, measured min 64% avg 96% max 137% over 569.0mm
    3/24/2019, 9:30:09 AM M591 D0 P5 C3 R10:120 E6.0 S0
    3/24/2019, 9:29:27 AM M591 D0
    Duet3D laser filament monitor on input 3, enabled, allow 10% to 120%, check every 6.0mm, current pos 1.4, brightness 92, shutter 17, measured min 92% avg 98% max 152% over 181.8mm



  • Thank you so much, that explains all perfectly. I see this: Duet3D laser filament monitor on input 3, enabled, allow 40% to 120%, check every 3.0mm, current pos 2.8, brightness 95, shutter 17, measured min 43% avg 92% max 102% over 2269.5mm


 

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