Final (hopefully) part of hardware work Besides putting everything into a nice aluminum enclosure, replacing the linear voltage regulator - which burns three times as much power as the whole circuits consumes - by an SMPS (based on the old L4962) an over-current-protection and two status LEDs have been added. laser-drucker_005122 Foto 1 (Milling aluminum is something else than milling wood. One cutter and nearly the front panel have been ruined. Dont know how to do it right, but very slow revolution and feed helped at least a bit. Maybe the cutter should have been cooled.) Foto 4 Kopie Here is the firmware for the Arduino.