Help with Printer filament jamming up

[SammamishHub]

While the filament thickness issues are certainly a red flag, I’ll offer a couple more things to check, based on my having the same issues a while back. I mean, you got some successful prints, and then things went bad. Sounds very familiar… I think I’ve actually had all of these problems at the same time before:

1) Check gears on your extruder drive and make sure there is no loose play at all in their movement. If either of the plastic gears turn independently of the other, or of the motor spindle, that’s bad. Even just a mm’s worth. In my case, the plastic at the center of the large gear started wearing out so that it wasn’t locked onto the hex screw holding it in place. So as a print extrudes and retracts, back and forth, it eventually gets to a place where there are so many retractions in a short period of time, that the gears are turning back and forth without actually driving any filament forward. I super glued it together long enough to print a new gear and mount it better (with a bead of super glue from the get-go.)

2) Make sure the hobbed gear is clean – grinding on filament fills the grooves and the teeth don’t grab like they used to.

3) Too high of a retraction distance. I’ve seen advice particularly about keeping the value low for PLA (1.2mm or less, YMMV), as it’s kinda sticky, and if you get too many retractions in a row (most slicing apps have settings for mitigating that situation), it can pull it up into the cold part of your hot-end assembly, cooling the PLA and jamming it up above your hot end.

4) Cross-wound filament. I often re-wind a new spool of filament manually onto another spool, because there are often spots where it’s been wound so tight by the manufacturer that the extruder can’t pull off the spool. Then it just grinds away on that one spot. But that problem would likely have been obvious.

5) A crazy thing I would have never guessed to try – I tried this piece of advice and it seems to be working – reduce the current to your extruder motor when using PLA (and back up again for ABS.) Go into your firmware and find the setting:

#define DIGIPOT_MOTOR_CURRENT {135,135,135,135,135}

and adjust one or both of the last two 135’s (extruder 0 and extruder 1.) “135” represents a value from 0 to 255, where in my Marlin firmware 135 => ~0.75A. I use 85 to have it pull about 0.5A. This will allow the motor to slip a little if it has difficulty pushing filament through the nozzle for a moment, rather than viciously grinding away at it.

[SammamishHub]

Just saw this after posting my reply. I have the cross-wound filament issue consistently with MG Chemicals filament, especially about halfway through the spool. It may not get stuck for good, but can cause gaps like you’ve pictured while it struggles to loosen the knot. I like MakerGeeks’ filament, but I’ve had this problem even with theirs - halfway through the spool.

[SummersideGuy]

I actually recently tried increasing the current to the extruder motor as per someones suggestion as before it was just skipping and not doing anything when there was a jam up

For extruder it is a simple bowden with an MK8 and a large bearing, nothing else and I even put in a new mk8 bearing to see if it was the issue but it was not

[3DPrintandStuff]

I’m thinking by saying “cross-wound” that could also be known as “twisted”

I have seen the effect of twisted filament upon a print, it can actually be so twisted that it’s able to pull back upon the extruder causing it to skip and click. If you feel the filament you should be able feel the tension within. When it’s not twisted, it feels relaxed same sort of feeling when you first place in the extruder. Sometime you can rotate the reel 180 in opposite direction of the twist or another method is to unwind until you see the twist; then wind back on the reel keeping the twist off the reel.

I done it a few times to almost the end of a reel but was able to print with once the twist was removed.

[SummersideGuy]

I had reduced the retraction to 2mm originally it was max of 4 as this has a bowden tube. My filament keeps getting bound up/stuck in the hotend somewhere. ive disassembled the hot end several times and restarted but within 30 minutes or so it is slowly getting bound up again

[SammamishHub]

Yes, exactly - that’s just the name that came to mind as I picture them moving the filament back and forth as it’s wound onto the spool. I get filament trapped underneath the next loop, and I can just push it into the knot a bit to loosen up a few more windings, but it’ll eventually hit the next stuck spot.

[SummersideGuy]

I do find the filament strand itself is very twisted and feels knotty and very springy, see photo. Is it hard to straighten this out, could this solve some of the issue. I know I will never order this crap brand again.

[PepCo_Parker]

Hello! I too have a Chinese printer kit, well, actually three… and I must say in the beginning it was rough but man once these things get working are they ever a piece of art! I have to ask, are you printing with Chinese filament? Some filament is actually extremely poor in quality, not just the diameter or shape but the plastic itself. My first printer I bought came with really good filament, but the next two had filament that was better off being burned than trying to extrude it. I also have to ask, as I made this mistake myself, when you cleaned the extruder assembly, did you do so with a torch of some type? I was unaware at the time, but there’s actually a piece of Teflon tubing in the upper threaded part of the extruder assembly and I had actually burned it right out, filament was constantly getting clogged without it and it was a massive pain until I got a new one and realized my mistake.

[PepCo_Parker]

Also if you live in Canada, depending where you are, I would highly recommend ordering your filament from filaments.ca, they do a great job, I’ve probably ordered upwards of 15kg from them

[SummersideGuy]

Ok I cut 2 10 meter sections off the roll. I then spent 5-10 minutes pull the twist out of each section. I was able to get 2 successful prints from both pieces after doing this, so maybe the roll is salvageable

[SummersideGuy]

On their website the majority of their pla is sold out

[ldanut]

I would do two things:

- check if extruder gear is not filled with grinded filament that will make it slip

- try a good quality filament since yours looks like a low quality one

[Namekkural]

I also bought a Chinese brand printer and had problems with hot end jamming from the start. I finally replaced the nozzle with a different brand and everything is fine now. Cost me 8 $ but was totally worth it. Don’t buy cheap extruded nozzles.

[shane_simon_779]

I had constant jams on my generic MK8 hotend plus a stripping drive wheel / clicking. I fixed it on mine by adding an oil wipe / vegetable oil drops on the filament while it is printing. This works for both ABS and PLA.

If your hotend is really buggered up, you may have to clean it using acetone first. Also, you may need to put a stronger or weaker spring in your tensioner - the default that came with mine was very weak and allowed the hob to slide.

Finally, double check that your extrusion rate is correct for your stepper / motor. My default setup was pushing slightly too much per turn and would instantly overload the head. Raising your heat a bit might also help, especially when using the oil.

[jimmyvonsnipe]

I use the Micromake Mini Kossels a lot, and they work flawlessly. Your printer looks quite similar. Definitely try some new filament. I use esun in my machines as it is easy to attain here in Australia, and works very well!

Regards,

James.

[dramaprint]

Hi, Filament problems could be caused by inconsistent diametar, you could change the spool and try again. Try to push the filament trough by hand and you should get consistent flow, if not nozzle needs cleaning. You could thy the cold plug method for cleaning. Also try to tighten the part that holds the filament against the hobbed bolt, hope this helps

[CALLMEBIGGPAPA]

I would honestly return the spool for that much of a variance in diameter. Double check that your extruder gear is aligned and properly tightened as well! Ps. I run a filament oiler/duster to help reduce the chance of jams and clogs.

[primaltalk]

I’d agree with the others that the most likely cause of the inconsistencies in feed rates is caused by inconsistent filament diameter. Where the blockage is concerned, it may also be that the filament gets too wide and jams, but I’d also look to heat creep as a possible culprit. You’re printing at a high temperature for PLA and, if the heat sink on your hot end isn’t that great, heat can flow up, cause the filament to expand and you’ll get a jam. From the looks of your hot end, the heat sink doesn’t look that great (compare it with a picture of an E3D from e3d-online).

[PepCo_Parker]

Ok, for the most part I order abs, haven’t really payed attention to pla on there. They normally keep quite good stock but lately every time they get stock it’s sold before I even get the email notification, guess the word about their quality has started getting out…

[SammamishHub]

I think I misunderstood what you guys mean by twisting. The more a filament sits out in the open air the more it holds it’s curl and gets brittle. Hard to see what’s causing the waviness in the photo, but I suppose I could see my little stock mini kossel extruder struggling to pull that through consistently.

I was talking about where you can’t pull the filament off the spool because it’s tangled up in the other windings; maybe it’s more common on large spools. Once a spool does it to me, it’s a repeating problem. Sometimes it clears with a tug, others it needs more TLC - so I just wind spools onto new ones once this happens, working through all the knots.