Inconsistent engraving depth

You see

A single fill engraves at uneven depth, some areas darker / deeper than others, or some areas appear unfilled while neighbors look fine. Sometimes a vignette: darker in the center, lighter at the edges (or vice versa).

What is happening

Energy delivered varies across the work area. Causes include focus drift across a non-flat surface, beam variation across the work area, material thickness variation, or mechanical issues affecting speed in some directions.

Fix

If the material is not flat

Inconsistent material thickness changes focus from one area to another. Wood that has warped, leather with thickness variation, etc.

• Flatten the material if possible.
• Use a thinner material that lays flatter.
• Run a focus test at multiple positions to confirm focus varies; if so, the issue is the material, not the machine.

If the bed is not flat or not parallel to the gantry

Check by jogging the head with a known distance from a fixed reference (e.g. nut + ruler under the head, measure as you jog X / Y). If the gap changes, the bed and gantry are not parallel.

Solutions are mechanical, level the bed, adjust the gantry, shim the machine.

If there is a vignette (center vs edges)

Could be the laser focus is slightly different at different head positions due to gantry sag or beam angle.

For diode lasers: the diode tilts slightly with the head, sometimes producing variation. Less an issue with rigid gantries.

For CO2 lasers with multiple mirrors: alignment of the mirrors can introduce vignette. See your machine's mirror-alignment procedure.

If certain directions look different

The head may move slower or faster in one direction (X vs Y, or forward vs reverse) due to mechanical issues. Check belt tension, motor torque, acceleration symmetry.

If a specific shape always looks inconsistent

The shape may have features that cause direction changes or slow moves where the planner cannot maintain speed. Run the Preview and watch for variable speed cues.

Verify it worked

• A test fill across a large area produces uniform engraving.
• The result matches what you saw on uniform material in calibration tests.

Still stuck?

• Focus test guide: at multiple positions.
• Material test grid guide.
• Post in the Facebook group with photos of the inconsistency and the design.