Welcome. I have Laser Optlasers PLH3D-6W-XF. I try to engrave anything on aluminum, metal etc. but unfortunately it doesn't work at all. I have already used the slower and highest speeds. What I do step by step for aluminum engraving: 1. Prepares the inscription. 2. I load it into OpenBuilds CAM Gcode Creator - Public Beta 3. I am setting the following data - Laser: Vector (raseter fill). - With Safe Height 10. (12 mm) - Laser: Power (100%) - Laser: Kerf / Line Spacing (0,1) - Fill: Angle (0) - Feedrate (X / Y) (180 mm / min) - Muliple passes: 3 I clean and degrease aluminum with acetylene. I smear the graphmetal with engraving paste. The distance from the ground is 35 mm. I just don't have the strength anymore, I was struggling with the settings. Unfortunately, Polish specialists and the manufacturer spread their hands and no help. So colleagues, help!
From the Optlasers web site Aluminum is HIGH heat conductance, like copper, 6w is not going to touch it since the heat is conducted away faster than the laser can input it. Like trying to boil a kettle with a cigarette lighter.
You even need double the power of a fiber laser for copper and aluminum than you do for steels. So you're probably looking at somewhere around a 50W fiber laser just for marking. A 6W diode laser isn't going to touch it. It'll do stainless if you pre-spray it with a dry moly lubricant, from what I've heard, but at the hobbyist level, aluminum is really best left to physical engraving spindles.