[matteo_galet]

Hello everybody,
today I borrowed my friend's laser machine-time to do some testing.
It's a cheap 500$ chinese 40w CO2 laser.

He uses it to cut plastics and wood, and to do some engraving on wood.

We tried etching the anodisation layer on an aluminum cover, but the results are quite disappointing.

We started with 30% power, 1000dpi, 250mm/s

The file is a one bit bitmap, where black is "engrave", white is "don't engrave".
Software is CorelDRAW Laser.

The thing works fine on paper, with horizontal scanning of the graphics; however, on the aluminum there are some strange borders around the graphics, that of course are not in the file.
The etched part should be solid.

We tried fiddling with power and speed, but other than a general dimming/brightness of the entire graphics, there is no difference and the border is always there.

You can see from yourselves in the attached picture.

Did you ever experienced something like this? What's your suggestion?

Thank you very much in advance