Laser not firing with GRbl 1.1h

LightBurn Hardware Compatibility GRBL
1

I cannot get the laser to fire

I have DYI laser engraver. I am using an arduino uno with a proteener cnc shield 3.0. running grbl 1.1h.

Grbl settings
$30 = 1000
$31 = 5
$32 =1

The PWM is connected to the Z+ pin

I cannot get the laser to turn on. I do not know what else to do.

2

If I hook the laser to the power supply directly it does not respond at all. The fan and power indicator light do not come on. Using s volt meter I verified that 12 volts is going to the laser. If I hook it up through the adapter. I power on the engraver and the fan and power indicator come on.

IN either case the laser does not fire and I am not getting any voltage from the PWM

3

When you say, “not getting any voltage from the PWM” how are you measuring that?

Your $31 setting is a bit odd - I’d expect that to be 0, though it shouldn’t hurt much as is - it’ll just reduce your PWM range a little.

4

Thank you for replying.
I had used a volt meter and placed on the ends of the wires from the z- pwm and the gnd.
Since then I hooked the laser to the adapter board and connected the Pwm as shown in the image to it.

When I connect external power the Laser fan runs and the red led inside the laser casing flashes. If I push the test button on the adapter the laser fires. When I first wired it this way, clicking the fire in Lightburn did fire the laser. But I could not get it to work after that. Below is a picture of my CNC wiring and laser w/adapter
CNCsheildwiring|666x500

again thank you for replying any ideas or suggestions would greatly be appreciated.

5

I don’t recognize that laser module, or the board you’re connected to for it. I think my best suggestion would be to check with the seller to make sure it’s wired correctly, and see if they have any tests you can do to make sure it’s working correctly.

The code to fire the laser with the Fire button and the code that drives the laser when running is basically the same. The only thing that might be different between those two is speed - if you ask the laser to go faster than it’s allowed to by the limits set in the firmware, it will reduce the laser power output to compensate.

You could try running really slow to see if it gives you a better burn. If it does, check the $110 and $111 settings to see what the maximum speed your board is set to allow. GRBL defaults for those are really low. (500mm/min, I think)

6

I was not getting any output from the laser at all. The laser is a NEJE 30 watt laser the test board came with it.

I decided to take drastic measures.

  1. I did the ancient Peruvian ritual to the Laser God.
  2. I smashed and burned my cats laser toy as a sacrifice.
  3. My cat sub sequentially peed on my keyboard. ( Not sure if it was meant as an offering or revenge)

I must of been blessed by the Laser God because my laser is fully functional.

Also on an unrelated note, I re-installed the GBRL 1.1h software.

Thank you for your assistance and the tip about the laser speed limit affecting the power level.

7

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