LC-40 potential power issue

[tom.lewis.1986 (TomL)]

Hi, I have a Genmitsu LC-40 engraver and while it connects and seems to work fine I have had issues cutting through materials. I’ve tried cutting 3mm acrylic and the official spec sheet says 8% speed and 100% power which equates to about 800mm/minute. Even when set to 100mm/m and with 15 passes and 100% power it’s still struggling to cut all the way through some parts. Is there a chance that the 100% power setting in Lightburn is not relating to 100% power on the laser? That was the only cause with Lightburn that I could think of unless anyone has any ideas.
Thanks
Tom

[berainlb (PY)]

What type and color of acrylic are you attempting to cut? Some will be harder than others and some others impossible.

As for power, can you do the following:

1. Run $$ in Console and return output. We’re interested in the value of $30.
2. Load a simple design and push File->Save Gcode. Save with a .txt extension and upload file here.

This will determine if LightBurn is at least requesting full power to the laser.

[tom.lewis.1986 (TomL)]

Hi
Thanks for your reply.
So the value of $30 is 1000 and I have attached a GCODE file.

The colour I was trying on was a light peach colour acrylic.
When you say some colours are harder/impossible to cut is it the case that darker colours cut more easily that light colours?
Keyring1.txt (67.4 KB)

[berainlb (PY)]

Reviewed the gcode and LightBurn is definitely calling for 100% power based on $30=1000. If there is a power issue it’s not from LightBurn.

If we assume for the moment that the laser is indeed running at 100% power then the issue is likely the acrylic itself or possibly the expectations themselves are overly optimistic. I’m not familiar with your laser but cutting through 3mm of even an ideal acrylic at 800 mm/min with 100% power in a single pass seems quite fast.

@tom.lewis.1986

The colour I was trying on was a light peach colour acrylic.
When you say some colours are harder/impossible to cut is it the case that darker colours cut more easily that light colours?

In general terms, yes. But it’s really about how much of the laser light is that particular acrylic going to absorb. So opacity as well as color of the material will have an impact as they’re not all equally absorptive of the 420nm light.

I’d imagine the light peach to definitely be on the harder side. Black seems to cut the best, white barely shows signs of cutting, and clear acrylic is basically impossible. I’m not so familiar with other variations.