Great video, thank you! May I ask what the four colored buttons (red, yellow, green, blue) in the front right corner of the bed are for?

Perfect Just what I was looking for!

good simple solution, this would also be easy to motorize

There are plenty ways to improve this cutter. Fist, remove gantry and remove that stupid exhaust 'choke'. It was built for small area engraving, so cutting and engraving is much better with full frame exhaust. Not possible to remove that choke without removing gantry. Second and most important improvement is to use 20 mm lens instead 12 mm. I bought head with air inlet, but that does not fit the head because of wrong 'gender' (male tread on the head, male thread on the air assist attachment). So, I made 3D print adapter and lens holder. Now I am able to cut many things that are not possible earlier with all that smoke going between head and workpiece. All the 'magic' is in that air assist if properly build. At first, tried 3D print air assist nozzle, but that is wobbly and not good. Later tried to cut 22 mm thick oak wood... okay, it is just for fun.