Z-Axis Problems: Layer Lines and Banding

Z-banding refers to regularly spaced horizontal lines or ripples that appear on the side surfaces of a printed part. It occurs when the alignment of layers is disrupted at the micron level, and it is especially noticeable on flat, glossy surfaces.

Mechanical causes include a bent or warped Z-axis lead screw, axial play in the coupling between the lead screw and the motor, a loose Z-axis nut, or dirty/dried-out lead screw lubrication. A thermal cause also exists: inconsistent extruder temperature fluctuations can produce a similar pattern.

Solution: remove the lead screw and roll it on a flat surface to check for straightness, then clean it and lubricate it with white lithium grease, and inspect the coupling and nut. PID calibration will eliminate temperature fluctuations. Quality prints come from well-maintained mechanics.