A warped board or a tilted sheet shifts the focus: in one place the laser burns sharp, in another wide and weak. If your laser has a Z axis that adjusts the focus, the app compensates. It measures the surface on a grid over your drawing, and while lasering Z moves along so the distance to the material stays the same everywhere.
Requirements
- Z axis present is switched on in the machine profile (Machine → Set up machine, section laser module). Lasers with autofocus from the catalogue already have it. Without a Z axis the height map does not appear.
- Focus the laser on the material at the origin X0 Y0 and set Z0 there. The map counts all heights from this point.
Measuring
Open Laser → Height map (focus) … or, in step 3 of the laser assistant, Measure height map. The app lays the grid over the laser paths of your drawing; you set the spacing (default 25 mm).
- Probe pin or touch plate: the app first probes the origin as reference, then every grid point. Check beforehand with Test contact that the controller reports the probe. Travel height and search distance refer to Z0.
- By hand: for lasers without a probe. The app guides you point by point: Move there, focus with a spacer or focus gauge, then Take Z or type in the value.
If a point deviates more than 10 mm from Z0, the app does not apply the map: lay the material flatter. Large jumps between neighbouring points (over 2 mm) are reported as a warning, usually an edge, loose material or a measuring error.
While lasering
With the map switched on, the G-code contains the focus height for every path point. The app splits long moves at the grid lines, more often on curved areas. Between paths the laser travels switched off: going up it moves Z first, going down X/Y first. At the end it travels above the highest point to the origin and back to Z0.
The laser assistant shows the range of the map and warns if paths lie outside the map (the height of the edge applies there). With the rotary axis on, the map does not apply. A Z step per pass in the laser profile is added to the map.
Saving maps
With an account you save maps under a name per machine profile, for example for a jig that always sits the same way, and load them again later. The app reminds you if a map is older than a day or the origin lies differently than when measuring.