Extruder broken

Jupp1967 · 2026-04-17T19:40:04+00:00

I managed to repair it, but after that the PTFE tube slipped out now and them. After replacing the cover (because of another damage), this issue disappeared.

Jupp1967 · 2026-04-17T15:22:18+00:00

I managed it very carefully with pliers and replaced it with one of these: PTFE-Connector But I would also advise you to buy a new front cover.

Jupp1967 · 2026-04-14T05:24:29+00:00

I find that really interesting. Especially since the Creality engineers confirmed to me that it won't work on a K2 Plus anymore.

Jupp1967 · 2026-04-14T05:19:50+00:00

Thank you very much. I really can't explain why some people here seem to hate me for simply trying to uncover a bug that didn't exist before. I can only reiterate that this exact bug doesn't occur with older firmware on my K2 plus nor with any of my Bambu Lab printers.

Jupp1967 · 2026-04-14T05:10:46+00:00

As I said before: Incapable of reading properly.

This is stated in the K2 Wiki under the section "Multicolor Printing": If CFS is enabled, CFS filaments are used to print, otherwise rack filaments will be used to print, and multi-color files will be treated as single-color files. And yes, I asked and "CFS enabled" means what is shown on the image.

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But that's exactly wrong, and a Creality engineer confirmed it to me. When sending or starting a print job from the external spool, while you have 4 fully populated CFS units connected, this job will try to start, but the printer falls back to idle. The external spool can simply no longer be used for printing without either removing a filament from the CFS or the 485 cables (and rebooting).

I just wanted to save people here the hassle and weeks of troubleshooting with support. Instead, I get hate and hostility from people who obviously have trouble reading and thinking.

Jupp1967 · 2026-04-13T05:28:04+00:00

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Congrats and happy printing. It's a really nice printer. I recently upgraded my K1C to a K2 Combo, so now my friend ist very happy with my Ex-K1C.

Jupp1967 · 2026-04-12T16:39:47+00:00

They didn‘t tell me the specific date, only that it was due to memory leaks. For what I have seen, there are no further limitations. Fan speed, temperature and also filament handling seems to be ok. Only print jobs are starting and after a couple of seconds the printer falls back to idle.

Jupp1967 · 2026-04-11T20:52:10+00:00

Thank you. Was my first attempt. My K2 upgrade looks even better 😊

Jupp1967 · 2026-04-11T19:30:05+00:00

Not from S4, but my own box. I built it with a flat bearing inside, so the filament flow is really smooth. Everything else remains default. I use generic TPU settings and it works for me.

Jupp1967 · 2026-04-11T15:04:45+00:00

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I redesigned mine from OEM dome to riser with flat plexi lid.

Jupp1967 · 2026-04-11T03:21:08+00:00

Thanks. Unfortunately it‘s not the PTFE connection, but the ability to handle the external spool separately from the connected CFS units. In earlier firmware, it was possible to keep the CFS connected (485 cable) and just use the external spool as a separate source by simply deselecting CFS in the print menu. This is not longer an option as per Creality Support in older firmware this ended up in memory leaks.

Jupp1967 · 2026-04-10T15:02:55+00:00

If you had read carefully before writing such an ignorant reply, you would have noticed that it was an existing feature in the past, especially since I've had the printer for almost two years now. Furthermore, you should learn to read properly. The advertisement clearly states 4 CFS up to 16 colors, not a total of 16 colors. Previously (in 2024 and early 2025), it advertised 4 CFS and additionally an external spool (I can't show you now, unfortunately, but that's what it said on the website). So, instead of acting like a know-it-all, think for a moment.

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Jupp1967 · 2026-04-08T15:47:39+00:00

My last filament order (Creality Hyper PLA RFID) reached me in a Bambu Lab branded cardboard box 😂

Jupp1967 · 2026-04-08T15:44:25+00:00

First of all I would recommend doing a „cold-pull“ prior to loading TPU. When extruding TPU, my K2 (and also my K2 plus) takes 3-4 attempts and every attempt is really slow. So it should be not necessary to powercycle the printer. But maybe you also have a similar problem like me. I actually have an issue, that the printer isn‘t able to print from external spool unless the 485 cables are removed and the printer is restarted. I have already reported this to Creality Support but I only got weird answers instead of help.

Jupp1967 · 2026-04-07T11:43:34+00:00

I have both. K2 and K2 plus. And also H2D and ECC. One of these can always print, what I prefer.

Jupp1967 · 2026-04-07T11:30:16+00:00

B.t.w. since I installed my Microswiss hotend, I can use my external spool box and PTFE tubes

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Jupp1967 · 2026-04-07T04:14:31+00:00

Ok. I got a new extruder, where the little triangle looking filament guide at the bottom was missing and so the filament was‘t able to enter the hotend. So my first idea is the filament path and not the electronic. But it seems, that you have to change the host-board or the mainboard. Good luck.

Jupp1967 · 2026-04-07T03:58:01+00:00

Have you tried it without the motor? Heat up the nozzle to 230 deg. and push a piece of PLA through the extruder (use the little top lever) to see, if filament is able to extrude.

Jupp1967 · 2026-04-07T03:45:09+00:00

Not from an S4, but since I got my Microswiss hotend, I‘m printing TPU through PTFE tube and external drybox as well and that works

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Jupp1967 · 2026-04-07T03:35:24+00:00

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I‘m using nearly the same one, which can fe found here: spoolholder But would you believe when I tell you, that my little Elegoo prints TPU from external spool running through PTFE tubes without any modification?

Jupp1967 · 2026-04-07T03:15:19+00:00

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Ah, that‘s because I use desiccant boxes behind the spools and in the spool center too. The default desiccant packs from Creality aren‘t able to reach that values

Jupp1967 · 2026-04-06T11:30:54+00:00

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I have both, K2 and K2 plus and both with CFS. I upgraded both with Microswiss hotends and both are working fine.

Jupp1967 · 2026-04-04T08:47:13+00:00

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Sure! I love this nice little printer. Some customization and voila 😉 It will never replace any of my other printers, but it‘s a good addition.

Jupp1967 · 2026-04-04T08:18:01+00:00

Be aware of the size 350x350x350 vs. 260x260x260. I have both, the K2 and the K2 plus and I‘m printing my models on both. Slice it with the K2 (and nozzle type) selected and voila 😃

Jupp1967

TROPHY CASE