That wavy pattern is what is often referred to as Moire. It is caused by the pulse of the 1/16th micro step of the stepper driver. Basically it pulses as it rotates and causes that pattern. This can be reduced some with proper VREF calibration of the stepper driver. Alternatively you could replace that driver with a 1/32 stepper depending on which board you have this can be a simple and cheap modification. Or you could switch to a geared extruder such as BulldogXL.
Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
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