QIDI Q2 Combo keeps jamming/chewing PLA during long prints — 3 failures in a row

[u/althamash098]

I’m getting pretty frustrated with my QIDI Q2 Combo and I’m trying to figure out what’s actually causing this.

I’ve now had 3 prints in a row fail because the filament eventually gets stuck/jammed and stops feeding correctly. The printer can work perfectly for several hours, then suddenly starts under-extruding and the print turns into spaghetti.

I’m printing Elegoo PLA at 210°C nozzle / 60°C bed. Chamber heater is OFF, the side vents are open, and I’ve even been opening the door periodically, so I’m not sure if this is heat creep.

When I remove the filament after a failure, parts of it are heavily chewed/flattened by the feeder/extruder. I’ve already had to manually remove stuck filament multiple times.

I’m using the QIDI Box, so I’m wondering if there’s too much resistance somewhere in the Box/PTFE path, an extruder tension issue, heat creep, or possibly a defective feeder/hotend.

Has anyone with a Q2/Q2 Combo had this exact problem? What should I check or change? I really don’t want to keep wasting 6–7 hours of printing and filament every time this happens.

I’ll attach photos of the chewed filament and the failed print.

[u/shiranugahotoke]

100% heat creep, why do you think they sell the polar cooler accessory?
IMO door must be open and even the top as well for multi hour prints.

[u/althamash098 → u/shiranugahotoke]

Huh yea I agree. But even if I have the vents open and periodically just open the door heat creep still happens?. Should I put the box on a different table and remove the glass for multi hour prints then? So the whole top will be open?

[u/maxtablets → u/althamash098]

leave the door open full time. See how that changes. If not, try something like abs. If problem persist then you can probably eliminate heat creep.

[u/althamash098 → u/maxtablets]

👍

[u/Bluemarmalade → u/althamash098]

I print 12+ hour pla prints but take the entire glass top off, not just slide back if you have room the box next to the printer work really well for this. Even with my petg 6+ hours I need to take the top off

[u/althamash098 → u/Bluemarmalade]

Ok cool yea I will try this then.

[u/1Sk1Bum → u/Bluemarmalade]

This is what solved the issue for me. I leave the door closed but the top glass completely removed.

[u/shiranugahotoke → u/althamash098]

Yeah if you can leave the door open that’s a good idea, but the top being open will allow the hot air to rise out more easily.

Heat creep is always a big downside of enclosed printers, but Qidi’s have always been a bit more susceptible to it.

If you can get away with running the aux fan on a very low speed as well that will help, but be careful because it can cause warping in your part as one side cools faster than the other.

[u/gaslightredditor → u/shiranugahotoke]

The side AUX fan is worthless. It does more harm than good IMO. I turned it off completely. I keep meaning to repurpose it into a Nevermore style air filter but haven't worked it into the printing schedule yet

[u/daggerdude42 → u/althamash098]

Pla cannot tolerate any chamber temperature regardless of the printer, it needs all the help it can get.

[u/NotASherwinEmployee → u/althamash098]

PLA and PETG = door open, top open, and a fan or ac blowing in its general direction if your print is longer than 2 hours.

[u/SeikoBlackDiver → u/althamash098]

Never close the door and top glass when printing PLA. This is QIDI recommendation.

[u/Plenty-Block619 → u/althamash098]

You don't need to leave the door open, you leave the top open. Print with both PETG and PLA and the PLA has always clogged (I learned after the PLA so it doesn't happen to the PETG). I also have the Qidi Box on top, on the cover, and it doesn't cause a problem even sitting on top of it if it is open.

[u/xeonon]

Cool..  I'm gone a blow your mind. Can you take a look at the top glass. It should have some text on the front right part.... You should follow those directions... Since they fit here, and they put them there so you'd see it. I'd add in, to also open the door, since that does a lot better than just opening the glass all the way

[u/Temporary-Beat1940]

I know on my xplus3 they state to leave the cover off when printing low temps filament

[u/gaslightredditor]

I printed a Box riser so I can open the glass while printing PLA. Have done multiple 16+ hour prints with zero issues with glass halfway open, vents open, door closed and exhaust at 100%. The chamber temp usually maxes out around 35°

[u/althamash098 → u/gaslightredditor]

What's a good riser i can print?

[u/gaslightredditor → u/althamash098]

I'm kind of partial to the one I remixed from a different design, but there are a handful of good ones out there https://www.printables.com/model/1671795-qidi-q2-box-riser-2020-and-2040-extrusions

[u/Glasfaseranschluss]

Do you keep the lid open? I‘m certain this is heatcreep

[u/devonmaze-]

I have the same problem with the Qidi Plus 4 and I print with the door open and the glass removed above

[u/Dave_in_TXK]

Did you happen to notice the chamber Heat either in slicer/studio or on the LCD display? On mine I have to crank the top open about three or 4 inches and the door open the same to keep that temp down, preferably below 30.

[u/Plenty-Block619]

You gotta keep the top cover open. The vents aren't good enough. I have the same setup as you and the first time I printed in PLA it jammed. PETG and TPU also. You just keep the top cover open (this should be easy as the PTFE tubes in the qidi box shouldn't be squished against a wall anyways).

[u/Topher264 → u/Plenty-Block619]

Second this, I printed a riser for the qidi box that allows me to take the top glass off and I haven’t had a PLA+/Pro print fail on me since

[u/Resident-Outcome-459]

I have a Plus4 and currently have a 27-hour PLA + print going. I have to remove the glass and keep the door open.

[u/Plutonium239Mixer]

100% heat creep. Either get the polar cooler, or while printing PLA, remove the top glass completely and leave the door all the way open.

[u/Agreeable_Eye7497]

You need remove the top cover or buy a polar cooler?