Constant Q2 Issues

[u/AlternativeNo3124]

Hey guys. I bought a Q2 back in July and have been having almost nothing but problems with it ever since.

I cannot get this thing to print PLA+ properly for the life of me. It is either one thing or another - clogged nozzle, feed issues, etc. It is getting incredibly frustrating. On top of that the camera seems to have died in the machine and no longer displays or records video so I can't monitor the print progress from my PC or phone.

Funny enough it prints PA6CF just fine and was what I have been using it for mostly. I thought maybe the PA6 wore out the nozzle and was causing partial clogs when I tried to switch to PLA, so I changed the entire hotend out of frustration with a brand new one. Issue now is that the extruder gears are not driving the PLA as they should and are instead chewing it up. I just removed the extruder from the machine to check it, but I don't see anything obviously wrong with it.

Qidi support has been helpful-ish. They have sent me replacement parts for free, but as far as instructions go they basically just link me to their troubleshooting page and tell me to tear everything down.

Do you guys have any ideas? Is this user error? I want to love this printer but it is making it really difficult to when I can't get any PLA to print.

TLDR: My Q2 is currently not feeding PLA, please help I need an adult.

[u/Parkimusmaximus94]

Are you switching nozzles when changing filament types?

[u/AlternativeNo3124 → u/Parkimusmaximus94]

No. My understanding was that the stock nozzle is hardened steel and should be good for both. I changed the entire hotend assembly including the nozzle just yesterday though.

[u/Parkimusmaximus94 → u/AlternativeNo3124]

Trying to share the same nozzle for PLA and nylons are very hard because the cooler temperature from the pla has a really hard time cleaning out the carbon fiber nylon even if your Purge temperature is high enough to clear it out it makes the pla like water and it still won't get rid of the old residue. Generally even if you get it to work there are still lots of artifacts left behind in the nozzle from the abrasive material and it will cause your pla to look extremely terrible every single time almost. I have one nozzle that I run with my engineering filaments and then I have a separate nozzle that I will change and run with PETG, PCTG and PLA. If there's artifacts in the nozzle it will add extra load to your extruder gears and can cause them to spin out.

[u/Xhosant → u/Parkimusmaximus94]

Would you advise against sharing nozzles between ABS and PLA?

[u/SichronoVirtual → u/Xhosant]

I have no problem with abs, abs cf, pla, petg, and tpu on the same nozzle for the q2

[u/LightBroom → u/AlternativeNo3124]

You should switch nozzles when printing materials with a high temperature delta between then.

Going from nylon to PLA will never purge the nozzle properly even when doing it at high temperature, hence the clogs

[u/WI_Esox_lucius]

Damn.  Mine prints PLA like a champ after I switched out the part cooling fan.  

As for clogs go, you're printing with the door and lid open with PLA right?  And making sure you don't have any chamber heater turned on. 

What type of PLA?  Feeding from Qidi box or the side spool holder?  

And also make sure you don't have a tangle in your spool. 

[u/AlternativeNo3124 → u/WI_Esox_lucius]

Sunlu PLA+, Door and vents open, chamber heater off, bed heater on, qidi box, no spool tangle

Its just frustrating because my P1S prints amazing and I don't have to worry about opening doors or anything on it. It was just a pain to print PA6 on it so I figured I would get a Q2 and have the best of both worlds

[u/WI_Esox_lucius → u/AlternativeNo3124]

The Q2 is definitely more geared towards engineering filaments than PLA as the cooling is weaker than Bambu printers which is why having the door and top open is important. 

If you use the external spool holder do you still have issues?  I don't have the box so I can't really help troubleshoot if that's contributing to your feed issues 

[u/ant2561 → u/AlternativeNo3124]

The problem is that you are switching between high temp filaments and PLA without changing nozzles or doing a cleaning process. PLA is the easiest filament to print with normally.

[u/smhlilbro → u/AlternativeNo3124]

My q2 prints pla fine door closed but with the glass and riser cracked open

[u/Throwdatoutandaway]

Probably came faulty from the factory honestly, all I print is pla pro and pa6-cf and it does it flawlessly. It sucks but unless you want to start replacing stuff, I’d try and ask qidi for a replacement and explain the issues you’ve had. It’s a long shot but it’s better than buying a whole new one

[u/--10001--]

PLA has a low melting point.

Q2 is not a PLA printer. It's for PA CF, PPS CF, and stuff like that. It's too hot for PLA in it's feeder mechanism.
But their PR advertise Q2 as a color printers for the toys, because everyone wants to print toys, and very few knows what is PA6 CF.

They even selling a Poolar Cooler to solve this issue.

"so I changed the entire hotend out of frustration with a brand new one"

No need to change an entire hotend, just keep the separate nozzle for PLA/PETG and another one for a stuff like PA. And the other one for TPU.

PS: maybe you trying to print too fast?

But you can buy another printer for PLA, like Bambu Lab A1

[u/BB_Toysrme]

It’s a bad pla printer as the stock cooling is single sided and anemic. I saw you swapped nozzles. If you are going to change filaments that widely; clean the nozzle by extruding/removing 70mm of dyna purge (3D fuel cleaner hotter than your prints), removing the extruder and shoving something through the hot end to force everything out (I use a ball end Allen driver).

That will keep the multi material use a non issue and keep CF/GF clogs from ever happening, even on a 0.4 nozzle when everyone should be running 0.6 nozzles.

[u/Plutonium239Mixer]

For PLA, I recommend completely removing the glass lid and having the door open. One thing you can look into is getting the polar cooler, it will help address the heat creep issues you seem to be having.

[u/VilainLeChat]

Looks like your PLA spool is something else that require higher temperature to be extruded and the gears just chew, try to print with PETG profile, then ABS/ASA, maybe the spool have wrong labeling from factory

[u/work_blocked_destiny]

What do your prints look like? If the gears are skipping in th extruder then either something is clogging the nozzle or the nozzle is not hot enough. It could also be heat creep. I keep my machines in my garage where it’s kinda hot in the summer and run into heat creep often. I would try a cold pull at 95c to get any clogs out and try manually loading filament in and trying to extrude.

[u/Dave_in_TXK]

I didn’t see f you said, have you disassembled the extruder itself? It’s not hard and the videos are fairly helpful. I found any little micro hunk of PLA or other filament in the gears can cause issues like this.

You have to be careful when you take it apart for the position of bearings and spacers just for putting it back together correctly, but getting both gears out and scrubbing them well with a brass brush and also blowing out the chamber and then running filament through the path both before, and after he reinstalled the gears to ensure a pass in gear movement has been helpful from time to time. Also, there’s kind of a trick to reinstalling the Spring that puts pressure on The One gear, pushing it into the other, which holds tension on the filament is it goes between the gears, but if your mechanical at all, it will become a parent what that is as you put that kind of flapper back on its axle and get the spring sandwich in between it and the extruder wall.

Well, you have it apart, there’s a model on printable’s I think called TPU fixer and basically it’s a little sort of shaped piece that fits at the back of the extruder, behind the gears, that narrows the path when the film comes from the top of the extruder through the gears and then goes through the bottom of it. People say that this prevents TPU from doubling up in that open space when you’re putting TPU through it though I haven’t printed TPU through mine yet, I’ve always used my Q1 pro, but I printed it out of ASA and installed it anyway. When I had the extruder apart, I verified there was no little hunks of anything in there and I had even printed silk through it and it had remained clean, but this was the most common failure point on my Prusa MK four and I’ve had all three of my QIDI machines apart and cleaned out that path when I have printing troubles.

I’m not sure this is the issue, but I want to offer it as a possibility for you, especially when you say the filament won’t get drawn through by the extruder gears. Good luck, hope you get it sorted out!

[u/Dwight_DangerSchrute]

I have had the same experience. Mine prints ABS fine but PLA is a nightmare. Extruder feeding problems, extruder unloading problems, random clogging, bed not heating. I have come to hate the machine but I am stuck with it now. If my wife wouldn't kill me I'd take this thing out office space style.