By double clicking the speed, another dialog comes up, allowing to change the details. Leave the power setting at 100%, smaller values will not actually change the laser power. Also leave on "Output" and "Show". "Air" does not have any effect.
Cutting Closed Paths
To ensure that there are no gaps in the ablation paths, we recommend using the "Overcut" feature. When engraving closed shapes, as it is typically the case for all isolation paths on a PCB, this will continue engraving past the end of the (starting another round of the closed path) for a small amount. Without this setting there could be a a small gap between the start and the end of the loop, causing an electrical connection, which is unwanted of course. The amount of the overcut only needs to be a fraction of a mm, we use 0.2mm.
Running the job
Finally, close the lid of the Laser4DIY and start the job. This is done by hitting the Start button