Laser Engraving transparent negative space

[cwozniak (Chris Wozniak)]

Hi,

I just started using Lightburn and took an all black image, removed the white background in photoshop so that it was transparent and then saved as a PNG file. When the laser is engraving, it is also engraving the transparent space. I’m guessing I have some setting wrong and would love some advice.

Thanks,

Chris

[justginbg (Gary Rowlands)]

How did it preview…

[cwozniak (Chris Wozniak)]

Looked like this:

[Album] imgur.com

[TomWS]

That’s your object, Gary is asking about the Preview window that shows the cut/burn sequence. Take a snapshot of that.

[cwozniak (Chris Wozniak)]

Sorry about that, attached the preview. looking at it, it explains the line to the starting point as well…

[bernd.dk (Bernd)]

Chris, the red track is only to show which way the laser is going, you can turn off traversal moves.

[cwozniak (Chris Wozniak)]

I saw that, It is burning the red track though. Doing some googling with transversal moves It seems that maybe its due to this:

Laser not turning off between cuts? (burning during travel moves)

If you have a GRBL device, and your laser is still on when moving between shapes, like this: [image] It most likely means you are using GRBL 1.1f or later, but do not have the controller in Laser Mode. Fix this by typing $32=1 in the Console window and pressing enter If you have a Ruida or other DSP controller and are seeing this happen, it is most likely a dying high-voltage power supply unit (PSU). The drive circuit that turns the laser power off and on tends to go first, before the part …

as I am using GRBL, however typing $32=1 gives me error:17

[justginbg (Gary Rowlands)]

Sorry guys hopping out here I know the square route of zero for grbl devices

[LightBurn (Oz)]

Read here: $32=1 error 17 · Issue #923 · gnea/grbl · GitHub

You’re likely using a version of GRBL that doesn’t have PWM / variable spindle mode enabled.

[cwozniak (Chris Wozniak)]

Is PWM spindle mode something I can enable in lightburn?