Laser test patterns

Power × speed — choose the power range and steps (rows) and the speed range and steps (columns), the cell size, and fill (raster engrave at a line interval) or outline (score or cut, with passes). The G-code is for GRBL in laser mode ($32=1): S values are scaled to your max S ($30, usually 1000), speeds become F in mm/min, and the power and speed labels are drawn in a simple stroke font so the result documents itself. The SVG gives each cell its own colour — assign each colour to a layer in LightBurn or your software using the legend CSV.

Kerf — cut the comb, push the pieces together, measure the total width: kerf = piece width − measured / pieces. Optionally cut a square hole and measure it too (it grows by one kerf). Feed the kerf to the box maker (/tools/box-maker/).

Fit gauge — slots of the material thickness plus a range of offsets, each engraved with its offset, and a test strip. The tightest slot the strip goes into tells you the press-fit clearance for joints.

Focus — a line at each Z offset around your focus height, labelled, for machines with a Z axis (instructions for the ramp method on fixed-focus diodes are included).