Waviness over XY

[KOLLIAK]

Hello!

Recently acquired a Geeetech A20M printer

I tried to print PLA with plastic from the kit, more or less

Now I switched to PETG plastic, and wavy lines appeared upward on the calibration cat. On the last upper layers it is not.

The photo is hard to see, but there are such waves on all 4 side surfaces.

What could be the reason? (I assume that perhaps a high speed of 60mm/s, or the defect has a mechanical cause)
A little later I will try to print at a slightly slower speed.

In general - the quality seems to be good

P.S. sorry for my English

WjZCbQrTlDk.jpg (106.07 KiB) Viewed 2452 times

[William]

Hi, You can check if your z-axis fixing plate is loose and you can tighten it.

Check whether the z-axis lead screw is bent. The bending will also affect print quality.

It is recommended not to print too fast. Reference range: 30-60mm / s.

I hope this can help you.