Visible banding

You see

A filled engraving or photo has visible banding, horizontal or vertical lines that interrupt what should be a uniform fill. The bands repeat at regular intervals.

What is happening

Two common causes: the scan interval is too coarse (the lines are simply visible because they are far apart), or the machine has a mechanical issue causing position drift between adjacent fill lines.

Fix

If the bands are at the interval spacing

The interval is too coarse for the material / power combination. The fill consists of separate visible lines because they do not blend.

• Decrease the layer's Interval in the Cuts/Layers panel.
• Or run an Interval test to find the right interval for this material.

A reasonable starting point: interval equal to your laser's spot size. See Scan interval.

If the bands are wider than the interval

The mechanical fill spacing is not what Beam Bench commanded, there is drift between adjacent lines. Possible causes:

• Belt backlash. Switch direction-of-engraving (bidirectional vs unidirectional in the optimization settings) and see if banding changes.
• Slightly skewed gantry. Square the machine.
• Y-axis steps/mm slightly off, causing each line to land at a non-uniform offset.

If the bands match the head's deceleration zone

At the edges of each fill line, the head decelerates. If overscan is too short, the head decelerates while firing, giving dark edges.

Verify overscan is enabled. See Overscan.

If bands are diagonal

Suggests gantry skew. Check that X and Y axes are perpendicular by cutting a square and measuring diagonals (should be equal).

Verify it worked

• After adjustment, a test fill engraves uniformly with no visible lines.

Still stuck?

• Interval test guide.
• Scan interval explainer.
• Overscan explainer.
• Post in the Facebook group with a close-up photo of the banding and the layer settings.