Hello!
Just recently finished building my own co2 laser cutter. I am from a quite poor place, so I can’t afford these expensive ruida controllers, in fact, I wouldn’t want to spend more than 50 EUR on a controller. That’s why I am using Arduino mega with ramps and running grbl on it. I had a diode laser before, and it worked like a charm. But now with co2, I can’t understand really why it is engraving like this. (Check photo) I think it is something to do with the minimal power, which I can’t change because I am not running a DSP.
As you can see, the edges where the laser has to slow down, are shaded, but they should be sharp stopped. Is it fixable, is it just trial and error till I find the right speed and power? When using constant power mode, the edges are deeper instead of being lighter.
Try enabling overscan and see if that helps. CO2 lasers have a relatively non-linear power curve, and they have a point at the lower end where they cut off completely if the power value drops below their firing threshold. The number will be roughly 10% of your tube wattage - for example, a 40w tube will fire at around 4% power, while a 100w tube won’t fire until about 10% or so. Using overscan will keep the laser moving past the sides of the design, so the deceleration mostly happens after the engraving, and that should help.
