Banding at regular intervals?

[tonyno]

Does that banding relate to your Z-axis thread pitch?

[mitchfx]

Does that banding relate to your Z-axis thread pitch?

You might be on to something. Interesting theory for sure. I noticed that the bands are positive (protruding) on one side of the model and negative (recessed) on the other. What this means I'm not sure but it doesn't sound like extrusion variation.

[jimmybuckets]

Its mechanical. You have something loose or if you have lead screw axis you may be seeing that its not perfectly straight. I would start from the tip of the extuder and give each part a wiggle...most likely something is slightly loose.

[maker2]

Very old thread but I"ll add to it anyway for the sake of completion.

Bands such as you have here, with ridges on one side of the part and valleys on the other, are caused by the Z axis not descending smoothly on one side.

It get's "left behind" as the other side goes down, thereby leaving the bed hanging at an angle.

That compresses the layers on one side of the part whilst lifting them apart on the other side.

Hence the ridges and the valleys.

Eventually the "stuck" side slips down and normal printing resumes for a few layers, before it happens again.

I have had - and fixed - the problem by replacing two sets of cheap bearings on the Z with some quality Misumi.

[KiloEcho]

See if the banding is in one axis either x or y or both if it is a mechanical problem it may give you a clue as to what the problem is.