Brand new K1C printer - layers shifting + lines on Z axis and extreme VFA on X axis

Hello,

I’m encountering a problem with the brand new K1C printer which I purchased to get “trouble-free prints out of the box.”
The printer was purchased about one week ago, and since then, I can’t get good quality prints out of it.
It’s a brand new “new generation” printer, but it prints worse than any of my old 3D printers: Anycubic i3, Geeetech Mizar S, and Flashforge Finder. Sure, it can print fast, but with the actual quality I’m getting, I just can’t use it.
As you may see in the attached pictures, I get extreme VFA on the X-axis (and some lighter VFA on the Y-axis), along with layer shifting and lines on the Z-axis on tall prints.

Since the first day, I have been trying to get better results and have tried everything. I’ve read a ton of forums and watched almost all YouTube videos about the K1 and K1C, but still can’t get decent quality.
The VFA on the X-axis and the lines on the Z-axis are just terrible.
I tried printing between 200-350°C and accelerations between 3000 and 9000, which reduced the VFA a little bit, but it’s still not acceptable. On 40-150°C / higher acceleration, the VFA is even worse.


I noticed that the belt(s) on the X-axis are not parallel to one another. The right side of the bottom belt is riding on the bottom end of the pulley, while the left side is riding on the top end of the pulley (on the left side of the printer). Check the attached picture.

What I have tried so far to fix the problem:

  1. Initially (after I performed all calibrations), I printed with factory settings/profiles using Creality Print 5 (since the beginning) and got the same bad results. The Benchy quality from the USB flash is also not good.
  2. I tried Orca Slicer, Cura Slicer, and Prusa Slicer, but the result is the same because I am sure the problem is not the slicer but rather the printer’s hardware/configuration.
  3. So, I rooted the printer to get full access to the Klipper settings, and again I performed all calibrations under Klipper, including: a) Belt tension verification/calibration (the belts’ resonation graph is attached)
    b) Performed X and Z-axis input shaping calibration and applied the suggested shapers (X and Z-axis resonation graph is attached). I also tried other shapers but without much success.
    c) Replaced the toolhead springs with softer springs to reduce low-frequency vibrations on the X-axis.
    d) Cleaned the grease from the X rods with isopropyl alcohol. But when the rods are dry, they make an awful noise when the toolhead moves fast, so I added some light machine oil, and now the toolhead moves smoothly.
    e) Cleaned the Z-axis lead screws and applied the grease supplied with the printer by Creality.

The K1C is a very nice-looking printer with very nice characteristics on paper, but I’ve never had to spend this much time on any of my old printers to get quality prints, as I’ve spent on the K1C. Instead of printing, I’m spending my time printing various calibration tests, cubes, shapes, etc., and yet I still can’t get decent print quality. I’m very disappointed and frustrated with my purchase.
I’ve seen a lot of people talking about the VFA and various problems with the K model, but I thought all of that was fixed in the new K1C model, so I believe my printer has some factory defects.
I would really appreciate it if the Creality team or community members could help me figure out what to do with my printer.





On my Qidi machines, both quite similar coreXY in operation, the X and Y belt tension can be a cause of problem, does the tension of the belts at the rear of the machine feel the same, though judging by all the data you have collected I’m teaching grandma to suck eggs.

Hi,

I’ve tried various belt tensioning methods:

  1. Using “auto-tension” with the help of springs.
  2. Setting tension to 110 Hz with a printed tension meter: https://www.printables.com/model/523382-creality-k1-belt-tension-meter.
  3. The “+2mm” tension trick (found advice on Reddit), which involves pushing the tensioner approximately 2mm further after releasing the screws and allowing the springs to initially tension the belts, to achieve higher tension.

The best result I got was with the “+2mm” higher tension.

As I mentioned, the belts along the X-axis on the right side of the printer are not parallel, and the bottom belt is rubbing against the bottom edge of the pulley. This might be causing Vertical Fine Artifacts (VFA), but I’m unsure how to fix it.
In addition, the X-axis rod has perpendicular friction marks approximately 15 cm long in the middle. I’m not sure if such marks are normal for graphite bearings.

I’ve completely removed the side panels and slightly loosened all the screws, then moved the toolhead along the X and Y axes in all directions before tightening all screws again. It prints slightly better now, but the quality is still nowhere near as good as on my older generation printers.



I have one like this works on the centre of the 2 belts in the centre, probably gives the same results though.

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Thank you for the advice.
I was considering getting one of these, but then I found that it’s essentially just a tire protector gauge with a 3D-printed part and only shows the deviation in mm. I’ve printed a simple GT2 belt tension meter (https://www.printables.com/model/46639-tension-meter-for-the-gt2-belts-of-i3-mk3s-or-prus), which works quite well according to my belt’s graph.
As for the Z-wobbling I think my printer has a problem with Z axis leads crew(s) so I’m thinking about to install oldham couplers with the anti backslash nuts.


That should fix Z wobbling problem.
Frankly I think that it’s weird that K1C “new generation” 3D printer doesn’t has anti backslash nuts, while most of old generation printers has it.

As for the VFA problem , after closerinspection I found that the upper X axis rod has scratch/friction marks wich indicates that there is an exesive friction between the rod and graphite bushing. Some folks fixed it by sanding a little bit the toolhead’s bering emplacement so the upper busching could freely slide on the rod. In that case it requires the use of 3D printed limiters as the screws heads wich are blocking the bushings from the right and left sides of the toolhead will be not enough to keep it in place.

Similar to oldham couplers, i have WobbleX on my Ender 5 plus. Might look at fitting them to my Qidi printers, but currently not suffering from z banding, they seem to compensate by not rigidly fixing the leadscrew free ends and having quite long bushings on linear rods.

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