Fine ripple pattern on walls (salmon skin)
A fine, regular pattern of small ripples or scales covers the walls, often looking like fish scales up close.
Also described as salmon skin, fish scales, vfa, fine ripples, strange pattern on walls, zebra stripes, texture on walls
Try these in order
Most likely and quickest to check first. Change one thing at a time so you know what fixed it.
Stepper motor drivers
Older printers with basic drivers move the motors in tiny jerks at some speeds. Usually the print is fine where the speed changes.
- Try printing the outer walls at a different speed; the pattern often fades at some speeds and not others.
- Upgrade the mainboard or fit smoothers if it bothers you.
Vibration at certain speeds (VFAs)
Fine vertical lines that appear only at particular speeds come from the motors and belts resonating.
- Print walls slower, or test a range of speeds to find a clean one.
- Check the belts and the pulleys aren't worn or rubbing.
Uneven filament or extrusion
- Try another spool, and calibrate pressure advance.