can someone please tell me the height in mm of the metal cylinder from the sculpfun s9 is? I lost it and now I am not sure how I need to set the correct distance between laser and material.
It will also depend on the type of lens employed. This is why a ramp test is a good idea.
Also, there are multiple YouTube videos for finding focus by observing obtaining the smallest spot.
With my 18W module the supplied tool was 18mm long, but the spec-sheet focal length given as 20mm, I have assumed the difference is the amount the lens is recessed in the housing (which looks ~2mm)