X1 Carbon Potential Flow Rate Issue

[Hollzarr]

Unmodded X1C, printing flawlessly for around a year, now suddenly out of the blue, I have rounded edges and gaps/under extrusion.

I can’t pin point the moment this started, but I was printing a STOLI board game set and noticed rounded edges, so printed several cubes and nothing changed.

Left Cube was after a fresh/new 0.4 nozzle.
Right Cube is today, 10ish prints later.

During a basic print of a filament sample swatch box, we noticed there were under-extrusion signs/gaps.
Then we had strong signs of a clog. (We then cleared the clog) but all other issues were still there.

We switched to 0.6 nozzle, it was flawless.

We switched to a new 0.4 nozzle, it was flawless again. However, 3-4 prints later, all issues are back.

Now, we are unsure of why, as nothing changed, no settings, nothing. We even tested with 3 brands of filament (Bambu PLA Basic, eSUN, Prusament), all with the same results.

Okay first layer, then 2nd layer+ it will be gappy.

I have tested on a new fresh cool plate bed and a textured bed.
I have removed all mods (Light mod, y splitter mod)
I have cleaned and checked the extruder.
I ran a flow calibration.
I have installed a fresh new 0.4 nozzle as stated above.
I have run several flow rate calibrations
I changed the filament flow rate %.
I have done full maintenance including tightening the belts.

Happy to answer any questions as best as possible and help will be greatly appreciated.

Thank you for reading.

[JonRaymond]

Nice job on presenting all of the info!

One thing I would check is how much play do you have in the head in reference to the carbon rods?

[Barryg41]

I had something similar. I went back and check the belts again. Going corner to corner about ten times. I stopped the x carriage fully in the back and tighten the screws. Then did the full calibration. My problem was solved

[Hollzarr]

Thank you for taking the time to get back to me.

I am sorry, could you confirm what you mean?

[Hollzarr]

Hi Barry,

Thank you for taking the time to get back to me.

I have gone ahead this morning and retightened the belts & ran a full calibration.

Sadly this was the print I did straight after.

[Hollzarr]

Good morning, 2nd day of dealing with this problem.

See the above comments, but today so far I have;

Retightened the belts & ran a full calibration
Ran a full dynamic flow calibration again,
Printed again using a K factor, received 0.060. (gaps in the first layer, but better extrusion on the second layer)

Increasing the flow rate to 100% and using the K factor;

Now I am genuinely still confused on why I suddenly would need to increase the flow rate to get sub par layers. so I do feel like I am still missing something.

Going to retry the 0.6 nozzle. Will report again after.

[partferret]

Assuming the 10 prints are back to back and you swap cold… Could it be heat creep? Not to the point of blockage, but the added friction will slowly mess with the flow rate.

[KanneKaffe]

I once had similar problems with the first layer. Something was also wrong with the prints. Then I printed a first layer and inspected it, it was pretty bad. It had some open areas.

I levelled the print bed manually. But it was actually completely fine as far as the distances to the nozzle were concerned. Nevertheless, it did help a bit. I then made sure to only adjust the screws under the heating bed a little at a time. I had read that the bed can also warp if the screws are tightened incorrectly.

However, I don’t think this has anything to do with the round corners. Here I would think about whether the filament is dry and dry it once as a precaution. But a K-factor of 0.06 is also somewhat unusual, as is the 100% flow. I recently had a filament with such values, but it was clear that the filament was unusable because it didn’t solidify properly even after printing. There must be something wrong with the mixture. I still have one of these spools and the filament behaves in the same way.

I’m curious to see if you can find a solution!

[Hollzarr]

Hello, sorry for delay, Ive been waiting for a brand new hot end to arrive.

Heat creep could still a strong contender here, but its weird how if it is that, why is it now its become an issue, we haven’t changed anything in our setup that affects heat.

[Hollzarr]

Sorry for the delay, I’ve been waiting for a brand new hot end to arrive.

The first print from the new hot end, is flawless again, hard to see in the photo, but it is, and this is without calibrating anything.

We are going to keep printing to see if the issue comes back.

Just testing a cube to check the rounded corners.

[StreetSports]

at 1 year, the teeth of the belts may be wearing down. allowing slop when changing direction. Just a thought.

Edit: I see you figured it out already.

[Hollzarr]

Hey! Thank you for reading through this thread.

Thats a very good shout actually.

Well, we are hoping it was one of the cables on the hot end, but we shall see, we are still going through some testing.

[MacMan67]

This is good info @Hollzarr , if you don’t mind me asking , and maybe I missed it , how old was the Hot End you replaced?

[Hollzarr]

Thank you!

The hot end we were using was the OG one we got with the printer, So around 10 months maybe? The 2nd hot end the spare that also came with the printer, but the thermister and such were from the original.

[Barryg41]

Makes me wonder if the thermal paste went bad somehow. Intermittent short on the thermistor.

Happy to see a new hotend is working for you though.

[lkraus]

@Barryg41

Makes me wonder if the thermal paste went bad somehow.

I had the same thought, then saw that the nozzle was switched a couple times before the hot end was replaced. I’d assume the thermal paste was renewed during the nozzle swaps.

But… can’t trust assumptions.

[Hollzarr]

Funny you say that, as I was taking apart the old one, the thermal paste was non-existent.

Until I added fresh on the new hot-end

[Hollzarr]

Correct, the thermal paste was replaced during the swap.