Looking specifically at the two-part black frame that contains the rest of the keyboard parts.
The lighting accentuates it and makes it look worse than it is, and it’s certainly not hard to live with, but it’d be nice to fix it.
Basic Ender 3 clone (Voxelab Aquila) with no real physical mods to speak of. PLA, .2mm layer height, 50 or 60mm/second. Happy to add any other details as requested.
the spacing between the ripples appears to be approximately the rotation distance of the wheels, is it only on that axis? ie. is it along the left/right side from the pics perspective or only the front/back?
i would check the wheels on the axis it appears for any damage or debris, and the wheel path.
My printer shares my home office with our bird (PLA printing only, and that not particularly often), and while I have an air cleaner that keeps it from being FULLY bird-dander central, dust is an issue for objects that sit. I’ll brush off the rail and belt particularly well for my next print.