If this is fundamentally about acceleration/deceleration as caused by tooth geometry on the pinion then I’d expect to see a couple of things be true:
- less of an effect at lower speeds; low enough speeds should make this almost disappear
- dissipation of the vertical bands gradually as the scan angle increased to the point it disappeared at 90 degrees since X-axis acceleration would be negligible since it’s only moving one line at a time.
However @Burn has stated that this doesn’t change based on speed or angle. 