Quote Originally Posted by AbuMaia View Post
Do you see ringing on the inside of the box as well? That's what I would expect if it had something to do with the extruder.
On the holes and notches in thin sidewalls, yes it is on both the inside and the outside. Whether it is on a corner, a hole, a notch, outside or inside, it's always on the right hand side looking at an upright surface. At least on my small test print, I know that's the exit direction of movement.

In other words, it's not that the same ripple is showing up on both sides of an extrusion. I should point out that with at least the test print I'm currently using for this, "thin wall" is still fairly thick - it's 1.75mm. I'm seeing Simplify3D use three passes for this 1.75mm wall.