Filament stops extruding after random number of layers
 
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EvilPenguin
(@evilpenguin)
Active Member
Filament stops extruding after random number of layers

I don't understand what's going on. I've had several successful prints, but now filament stops flowing through my extruder at some point in a print.

I've looked all over the forums and I found this:

https://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/-before-you-ask-troubleshooting-video-updated--t472.html#p39190

Extruder stops extruding filament. (Works for a while then stops)
Common causes:
1. Tension on the extruder springs is set wrong (see above).
2. Filament spool is not free to turn creating intermittent friction or binding. (Or filament is not wound well on the roll). Fix filament holder. Consider alternate designs on Thingiverse.
3. The extruder “Hobb-Goblin” pulley is dirty and debris is following the filament into the extruder.
4. The extruder “Hobb-Goblin” pulley is warn and is no longer grabbing the filament.
5. The extruder cooling fan (that cools the heat-break) is not keeping the heat-break below the filament melting temperature so it is melting and causing a clog. If in an enclosure, open the door. Verify the fan is running.
6. Intermittent (or broken) connection in the cable bundle for the extruder stepper (not stepping), cooling fan (not cool enough) or thermistor (causing the printer to think the temperature is cooler than it is, causing it to increase temperature beyond the range of the filament). Intermittent comes and goes as the cable flexes at different Z values.
7. Bad temperature for the filament.
8. Set screw on the extruder “Hobb-Goblin” pulley has come loose allowing the pulley to spin independently of the extruder stepper motor.
9. Set screw on the extruder thermistor is loose, creating a poor temperature reading of the heat block (see 6).
10. Poor quality on the filament diameter. Measure it with a caliper over a short span. Try a different spool.

I've been through just about everything on this list. I'm using hatchbox filament, which I've found consistently to be 1.75 ~.01mm... just for fun though, I measured the current spool and it's good.

  • I've set the tension on the extruder springs several times. I had them initially WAY too tight, but have since adjusted them to be correct.

  • The pulley is in correct alignment.

  • I've examined the hobbed pulley and I can't see any damage.

  • I've also cleaned it throughly with a brass brush and toothpick, the blow the whole thing out with canned air.

  • The spool is turning freely.

  • The fan is running.

  • I've run two PID calibrations. I'm printing PLA at 215.

  • I've checked the set screw for the pulley AND the set screw for the thermistor. Both are tight.
  • What am I missing!?!?!!

    This is driving me crazy. I've been working on solving this problem for 2 days now.

    I've attached a picture of the filament that I pulled out which is pretty typical of how it's looked, the only difference being how soon I catch it. It is clearly grabbing the filament as I can feel and see the pulley marks... then for whatever reason, it stops extruding, and the pulley starts eating into the filament as it keeps trying to send it down to the nozzle. (The top of the image is the nozzle end. The mark above the gouge the pulley makes is from the pliers used to pull it out of the extruder).

    Posted : 26/02/2018 11:47 pm
    EvilPenguin
    (@evilpenguin)
    Active Member
    Topic starter answered:
    Re: Filament stops extruding after random number of layers

    New development:

    I went over EVERYTHING again. This time I even switched to a brand new spool of hatchbox PLA.

    I printed a test frog on the SD card and it printed fine... all the way through.

    Then I run the print that failed last time and it failed again IN THE EXACT SAME SPOT. So, now I'm thinking it has something to do with the way Simplify3D is slicing the STL. Has anyone experienced this before? Can someone point me in the right direction of how to fix this? I really like S3D and it works flawlessly on my Flashforge for years. But, basically, it can't be the printer. Not unless it's an amazing coincidence that it failed in EXACTLY the same spot and in exactly the same way. It's like looking at a duplicate of a failed print.

    But, I'm totally lost as to what my next step should be on how fix this...

    Posted : 27/02/2018 5:03 am
    Martin Wolfe
    (@martin-wolfe)
    Reputable Member
    Re: Filament stops extruding after random number of layers

    It could be the model you are printing. If it does not have enough strength/bed-adhesion to self support the model could be bending as the extruder moves by raising part of the model, leading to no room for the filament to come out giving raised pressure inside the hot end and the associated extruder gear slip you are showing.

    Martin Wolfe

    Posted : 27/02/2018 6:47 am
    BillC
    (@billc)
    Reputable Member
    Re: Filament stops extruding after random number of layers

    You may be printing at too high a nozzle temperature. What is the range on your spool? This thread shows other users printing Hatchbox PLA at 195 - 200.

    https://shop.prusa3d.com/forum/print-tips-slic3r-settings-kisslicer-model-repair--f12/hatchbox-pla-settings-t1805.html#p14001

    Too high temperature could be causing heat and molten PLA to rise into the heatbreak increasing the pressure needed to feed fresh filament in. The frog may be small enough where the problem does not show but it does in a larger/longer print.

    Bill
    Tagaytay City, Philippines
    Founder member of Philippines Prusa Printer Owners FB Group
    Sponsor Pillars of God Academy in Bacoor

    Posted : 27/02/2018 7:04 am
    EvilPenguin
    (@evilpenguin)
    Active Member
    Topic starter answered:
    Re: Filament stops extruding after random number of layers

    It's definitely the model. But, I'm still confused and I've never had a model cause the extruder to stop sending filament before.

    Anyway, let me give the update:

    I ran the STL through netfab and ran a repair. Then after the repair, I put it into S3D and spit out the .gcode. The model printed fine and all the way through... it got crazy at the end after I ramped the speed back up to to a 100% (I had to bring it down so I could print out a leaning structure that I didn't put supports on). So, after seeing it wonk out after putting the speed back to 100% (which I set at 60 mm/s), I wanted to do some speed test. So, I downloaded a benchy STL off thingiverse and sent it to the printer. It seemed to be printing fine and I went about doing other things. When it finished and I checked it out, it looks like what it was previously doing... basically it got about 1/4 of the way in and then the extruder just stopped sending filament (also the print is just horrible... not sure what's going on... but really bad).

    The benchy was set to 80 mm/s for the speed test... but I don't think that could be the cause of it inability to send filament at a certain point, right?

    I'm going to run benchy through netfab and repair... but I really don't understand why I have to do that... if I send one of these models to my flashforge, it will print fine without needing to be "repaired" first.

    The models are getting great adhesion, it take a razor blade tool to get them off the bed. I'm running the hatchbox at 215 for the 1st layer and 200 for 2nd layer and beyond.

    Just as a point of reference, I run hatchbox through my flashforge at 220 and get beautiful prints all day (as long as the bed is level).

    I'll try lowering the filament temp to 195 as well... maybe the combo of things will help.

    Posted : 28/02/2018 12:24 am
    EvilPenguin
    (@evilpenguin)
    Active Member
    Topic starter answered:
    Re: Filament stops extruding after random number of layers

    Solved, I think!

    Successfully printed out a Benchy. It was my retraction distance setting. It was WAY too high, which I think I did accidentally and missed basically putting in a decimal.

    Now on to tweaking my settings until I get the perfect Benchy at the fastest possible speed.

    Posted : 28/02/2018 2:50 am
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