Laser 15w grayscale help

[dott.condorelli]

Hello to everybody,
I'm new with engraving and i bought a 15w diy laser engraver on aliexpress.
I'd like to engrave wood (poplar 4mm). While b/w goes perfect and i can downgrade laser power, i tried many times changing speed and laser output min and max, but it doesn't engrave grayscale right, it is always to dark and burn.
Someone can suggest me how to set it? i need to chang laser with one of 2500mw?

I guess i change the firmware. where can i check which firmware i have?

Which is min and max range for laser power? 0-255 o 0-1000.
If i want to cut wood, how could i need to set laser power?
Thanks for your help and i'm sorry for all this question.
Giuseppe

[Zax]

Laser range is determined by the firmware, using T2Laser defaults it's 0-255 (this makes sense as the Nano output is 8-bit, using 0-1000 requires Grbl to downscale the output value to 0-255).

If you max out feed rate (say >2500) then you would need to reduce laser max.

[dott.condorelli]

When i set laser power manually to 1000 it seams to be stronger than 255. Does it mean i have grbl firmware?

[Zax]

It means you aren't using my firmware and parameters. If you enable debug mode you will see the connect string, my default firmware is Grbl 1.1e. In the Machine menu you can display the Grbl Parameters, laser max is $30 so if that's 1000 you know it's not mine.

[ggallant571]

I have a 15W module and am curious about your results. I suspect mine is an overpowered 6W diode with Chinese documentation.

[dott.condorelli]

I upgrade firmware to 1.1e. When i set max power more than 1000 (es. 2000) it goes back 1000 and not 255. Is it right?

[ggallant571]

You have user parameters that set the size, max speed, acceleration, and PWM range. $30 displays the PWM range.  You can use a terminal emulator such as teraterm to display and adjust the parameters. I think T2 & BCL both offer GUI interfaces.

[Zax]

Why would you set it to 2000?

The output range is 0-255 (it's an 8-bit PWM signal) so it is best to leave $30 at my default of 255 and keep laser max at the same unless you need to reduce it because of excess power.

[dott.condorelli]

I got a good grayscale with min-max 5-120 and speed rate 3000. If i reduce speed, from 65 to 100% is all dark

[ggallant571]

There are two difficult time periods when laser etching:

  1. Setting up the fixture, selecting a tool set, and calibrating the machine.
  2. Getting the etch to look right to you with minimal effort.

The first stage passes but after almost 3 years I am still trying to satisfy the second. I maintain a log with settings for each medium, diode and lens along with notes on etch line width and cutting parameters.