Mind you, we're talking about 1 (one) cardboard box worth like $1.

Lesson 4: etching at anything above snail speed seems to introduce jitter into the lines. I haven't yet figured out if this is due to device imprecision or the material "moving around" while the head is jumping. I can imagine the latter gently vibrating. These are 30 micron lines

FTR, this is a slinging IR laser, not fiber. The latter would be much more appropriate for this task, but I wanted one that will be useful long term, not just prototype marking, so I also have a diode that can cut wood.

Lesson 3: "Less power" != less power. Less power in the UI means PWM with full blast, just less frequently. Which means that if 1% is enough to strip the oxidation layer, making the head go faster will not result in lighter burn... rather:

The rationale is that for any material that actually *burns*, small errors are not visible. But for metal where a spot is a spot, no luck hiding it.

You can fix both by sacrificing time: only burn on one direction and bump the scan-line resolution

Lesson 2: While etching, the laser is shoved back and forth on it's axis, and it's turned on and off when it should burn. You'd think it's precise. Well, no, it's not 😅

There's a visible error between the directions. Also they try to save time and not run densely enough.

Lesson 1: Black anodised aluminium gobbles up IR wavelength. That means, you can throw as much or as little power you want from a 2W laser at it, it's gonna burn that oxidation layer straight off. Doesn't matter if it's etching (filled area) or scoring (outlines only).

Mars is just a layover