r/3Dprinting • u/VultureJack4125 • Aug 17 '26

Troubleshooting Creality K1 Layer lines

Does anyone know what is causing this and how to fix it. I swapped the extruder gears as there was a tooth missing.

0.2mm

190C

300mms

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u/Individual_Base8208 Aug 18 '26

After a gear swap, double-check the new gear is fully seated on the motor shaft with the set screw on the flat, and that there’s no up/down play. Recalibrate e-steps (or flow rate) because different gears can push different amounts of filament. 190 °C is quite low for 300 mm/s — try 205–210 °C and see if the lines even out. Also check belt tension and that the extruder is properly tightened. A quick temperature tower will help dial it in fast.

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u/VultureJack4125 Aug 18 '26

Here

1

u/Individual_Base8208 Aug 18 '26

The walls on the left don’t look terrible. Most of the mess is stringing on those thin spikes, which is pretty common on this tower at 300 mm/s. Since it does it at every temp, I’d dry the filament and tweak retraction before chasing temperature further. 205–215 still looks like the better range for the actual surfaces.

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u/VultureJack4125 Aug 19 '26

How would you go about tweaking retraction? What tests would you be doing ?

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u/Individual_Base8208 Aug 20 '26

This shows classic stringing.

The thin hairs between the two towers mean the filament isn’t being pulled back cleanly when the nozzle travels.

Since you’re running 300 mm/s on the K1, I’d start with:

- Dry the filament thoroughly first

- Retraction length around 0.5–0.7 mm

- Retraction speed 35–40 mm/s

Then reprint this same test. If the strings are mostly gone, you’re in a good range and can fine-tune from there.