Creality K1 prints circles oval by a constant 0.3–0.35 mm at any size
Printer settings.
- Printer: Creality K1.
- Slicer: Orca , Prusa.
- Filament does not affect this issure.
- Nozzle and bed tempereture do not affect this issue.
- Print speed: outer: 100 mm/s, infill 150 mm/s. Acceleration: 1000 mm/s^(2).
- Retraction settings do not affect this issure.
Hi!
I’m trying to diagnose a dimensional error on my Creality K1.
Circles are consistently oval and the difference between the maximum and minimum diameters remains almost constant: approximately 0.3–0.35 mm regardless of the circle size.
For example, a nominal 25 mm circle measures roughly 25.2 mm in one direction and 24.9 mm in the perpendicular direction. The oval is stretched along the XY diagonal.
I tested circles of different diameters, and the error does not scale proportionally with their size. It remains around 0.3–0.35 mm. Because of that, it does not look like a simple rotation_distance/steps-per-mm calibration issue.
The most interesting test was changing the stepper pin assignments in Klipper so that the print coordinate system was rotated by 90°. After doing this, the ovality also rotated by 90°
In other words, the error followed the motor/kinematic coordinate system rather than remaining fixed relative to the physical bed or the model orientation. In my mind it excludes the geometry of the frame. But correct me if I'm wrong.
I turned the input shaper and pressure compensation off. Tried extremely low speeds like 60 mm/s, 1000 mm/s^(2). No result.
I also printed a 100 × 100 mm square frame and measured it carefully with the narrow jaws of the caliper to avoid the corner bulges. You can see the results in the picture. Overall print quality also leaves something to be desired.
The belts are tightened, the frame is rigid. I'm at a loss here.
Any ideas are welcome.