I’ve owned my printer for 2 weeks. For the first week, all of my prints were flawless right out of the box. I had 4 spools loaded into the CFS. All of a sudden, I tried to test print with PA6. Up until this point I had printed with PLA and PETG-CF. The print all seemed to be working fine through the initial calibrations. The printer head then went to the back (by the poop chute) and just sat there at 300C. No warning, no errors, nothing wrong that I could tell by looking at the machine or Klipper. It just does nothing. Since then, every print does that. No matter the filament. I print from the spool fine. I’ve tried advancing the filament into the hot end manually and it will not advance when the filament is coming from the CFS. The filament detector works fine and the blue light is on. It just hangs and will not doing anything. Again, I’m not getting any error messages, so I’m not sure where to go from here. I did notice that some pieces of PA6 did break off into the CFS buffer so I opened that up and cleaned it out. The blue light is always on (not sure if that’s expected). I won’t be printing PA6 from the CFS anymore. But, now nothing works. Looking for any recommendations as to where to start. The problem has to be in the CFS somewhere.
I’m having the exact same issues. I just bought myself k2 pro 2 weeks ago also.
It has been printing awesome until I tried running PPA-CF through it. Now it does what yours does and hits 300 and basically freezes u. I have to hit power switch to cancel it.
At first I thought it was plugged up so I replaced the tip but that did nothing. Then I thought maybe I damaged something when removing cf from extruder….?
I have a support ticket submitted but it will probably be a response in Chinese!
I tried spool holder and first try didn’t work so I tried pushing harder on filament and got past a restriction and it printed fine. I think something is damaged in there from either carbon fiber or from taking extruder body off. I’m going to tinker around and see if I can find anything else
I have a feeling it’s the cutter creating a restriction maybe carbon fiber jammed it up and it’s not retracting 100%(on mine anyway) I’ll let you know when I replace it or clean it. I’m printing a file right now with spool so it’ll be later today that I dig into it.
Update on my situation. I have been printing fine on the spool. The cutter is also working fine. I believe the system is hanging on the “extrude” command. When printing from the CFS, it would always extrude, and that is where it would hang up. When loaded with the spool, if I try to extrude manually from the menu, it does the exact same problem. It goes to the back over the waste chute, heats to 300C and does nothing. Now, the only way for me to switch filaments is to load in a new filament and begin printing something… which of course doesn’t work because the filament hasn’t been loaded into the nozzle. After a couple layers of printing a test ring, I can see the old filament empty out, then wait until my new filament begins printing. I cancel that test print and then the next print is fine now that it’s fully loaded into the hot end. This has to be some sort of firmware or motherboard issue in my eyes. I had Grok search the forums and reddit and I saw a couple of other users that got sent a new motherboard for this issue and it corrected it. I’d hate to think a motherboard went bad in a week, but that’s what it is pointing towards, in my situation at least.
“heats to 300C and does nothing”. Just by curiosity, have you tried to change it for 295°C instead of 300°C ?
There’s no changing it. It doesn’t respond.
Hi, The problem is that firmware version where it cooks at 300 degrees at the poop chute and glitches out. Get a USB go to the Creality downloads and get the previous firmware that ends in 66. Put it on the USB and it will say update, yes then turn off automatic updates on the machine. I used ChatGPT to help me figure it out. It said that is a known issue. The special carbon fibre filaments don’t like the CFS. Really need a heated Space PI X4 or a single heater. I am new to 3D printing so I have had to fix errors galore myself. When they work they are great. Also learned the glue stick method is not required. Use isopropyl alcohol and wipe the plate and you get excellent adhesion.
I have some more testing to do with filament changes but rolling back the firmware has, so far, appeared to fix the issue! Thank you!
Update: after a few successful prints, I again attempted to print with PA6-CF from the spool. The printer did print. However, when I went back to the CFS, I now have the same problem. Since this problem was with the .66 firmware. I tried updating to the latest .94 firmware. Same problem. I tried to roll back to .66 like I did last time and I have the same problem. ChatGPT is sugggesting this is a communication error coming from the CFS. This has happened both times when there was still PA6-CF in the nozzle and the machine went to extrude.
Is it only the Carbon fibre filament, switching from that to the CFS? I bought some expensive Siraya tech PPA-CF & it printed well but it is very brittle so I heat it up in the Space PI X4 and keep it heated while printing. I did have it block the filament though. Took the nozzle out and it has PPA-CF stuck in it. The nozzles are not that expensive so I just changed them. I have also had the little blue light sensor that detects blockages behind the extruder stuck on. I had to put a new circuit board in. Fortunately all of these parts are available at Aliexpress for $4 then Creality send me one as well under warranty.
That PPA-CF that was stuck in my nozzle, even with pliers I still haven’t been able to remove it. I could use a gas flame to heat it up but it’s alot of stuffing around for a nozzle. I have only tried 0.4mm nozzles. I think when using the PPA-CF it is almost worth using an exclusive nozzle maybe even bigger 0.6mm or 0.8mm then changing the nozzle back to the CFS nozzle. I am still learning myself and there are so many settings! Plus learning CAD
That worked for mine also! thanks a lot.
after I installed 66 version, printer asked if I want to update to original version. Can I do that and it’ll work as it did before I ran carbon fiber throughgh it?
I was able to take the extruder off and heat the nozzle up to 300C. Then I pushed a rod down the nozzle and manually extruded the PA-CF.
But I haven’t been able to fix my problem with the CFS and the extrude issue yet. I think something happens when you have a high temp filament like PA-CF and your machine goes to load in something like PLA and only heats the nozzle to 220 and tries to load it in. The PA-CF is still solid and it can’t be pushed out. Right now I’m just printing off my spool again fine with PETG-CF. Still working on a solution….
Would analyzing the Fluidd logs and/or the Klipper logs provide any hints about what’s going on? Just a thought.
I’ve tried to do that with ChatGPT. And it has indicated that the problem is in the CFS firmware. It gets pretty complex after that for me. I don’t see an option to roll back any CFS firmware. Here are some samples:
This failure mode is strongly associated with CFS-related firmware hangs or job-start macros locking the printer when the CFS fails to report its state. It is not a normal slicer behavior, and the 300 °C temperature is a known failure point for certain K2 Pro firmware builds.
1. Confirm Whether This Is the Known CFS Firmware Lockup
On several early K2 Pro firmware versions (both screen firmware and motion-controller firmware), a bug caused the printer to freeze exactly at the moment it should purge material over the chute. The CFS handshake would fail, and Klipper would deadlock.
Key indicators that match your description:
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Heat rises directly to 300 °C even if your print does not require that temperature.
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UI becomes non-responsive: cancel/pause/temp changes do nothing.
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Happens only when the CFS (Creality Filament System) is connected.
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Job never gets past purge.
If all of these match, the root cause is almost certainly:
CFS communication timeout → toolhead purge routine hangs → firmware locks heater state
No, switch off automatic updates. I asked Creality weeks ago if they have fixed the latest firmware and no answer. I would much rather have working 3D printers on the 66 firmware than upgrading for a ton of errors.
You could as soon as you finish printing with PA-CF manually pull it out the back. The problem if you leave it is the little magnetic blade in the extruder cuts it off but it will leave some PA-CF in below where it cuts. That needs 300 degrees to heat up to make it print & clear it out to go to the next PLA or PETG. You can manually on the machine screen tell it to go to 300c, then extrude the new filament from the CFS & turn it down as you see the new filament come through. Then when you print it will revert to your printer temp settings from the software on the laptop. Just an idea.
ChatGPT is not perfect. I should of mentioned that. 99% of the time it is great but it took me on the CFS firmware update path. It had file names, I asked Creality for them but no answer. As long as you run the 66 firmware everything works. There are alot of changes in the version 7 software as well now!
Update (final update maybe?):
Here’s what I’ve discovered in my situation. Both times the K2 Pro “broke” was immediately after trying to print PA6-CF filament. Once was from the CFS (not recommended, as it broke off in various places including inside the buffer), and once was printing from the spool. I believe something happens when you load a lower temp filament for your next print. The nozzle doesn’t know to get hot enough to extrude the 300C PA6 filament out while it’s loading in 220C PLA filament in. At that point, something “breaks” in the machine. I think initially, rolling back the firmware reset whatever was “stuck” in the settings. After printing the second time with PA6-CF, it had the same problem. So, now, when I print with a high temp filament like this, I avoid any “extrude” command, That command could come from the CFS when switching filaments, or from the LCD panel on the front of the machine. Instead, I load the new filament I want to use (after PA6-CF), heat the hot end to 300C and manually advance the extruder until I see the new filament coming through. If it’s PLA, it just runs out of the nozzle because of the high heat. As long as that “extrude” command is not run, I don’t seem to have the issue. I’m now printing fine from my CFS again with various PLA, PETG and PETG-CF filaments. I had to get to this point by flashing back to the previous firmware once again to clear the issue. I haven’t tested it yet, but my final test is to now update to the latest firmware and hope everything keeps working ok. The machine worked flawlessly out of the box and updated with all my PLA and PETG with the CFS until I printed with PA6-CF and then tried switching back. I hope this helps someone in the future.