2.8W Laser Trials (Part 1)

I see on YouTube a couple other people have fitted their MPCNC with this laser and a mess of people have downloaded the redesigned tool holder I posted on Thingiverse. Still working through this, thought I’d share some practical examples on how to get it to work.

Always Be Careful
Reality check, it’s a 3W laser so there’s only so much you can reasonably expect it to do. Think of it as EZ Bake Oven with a mean streak that can blind you in a heartbeat if not handled properly. I’m already partially blind for other reasons so I don’t skip the safety precautions. Personal favor, follow my lead on this and always treat this tool with respect.

Materials, Echos of High School Modern Physics
Reflective materials like metals scatter the laser radiation so there’s not enough energy delivered to the material to cut or even etch in most cases. Anodized aluminum is an exception because you’ve got a non-reflective surface.

Acrylic materials come in many forms. The frequency of the light for this laser diode is 445nm (aka blue). To cut, or even etch, the acrylic needs to be opaque at 445nm. If it’s visibly opaque you’ve got a shot. Clear acrylic, no chance because it’s transmitting rather than absorbing light at that frequency, same goes for blue or green tinted transparent. Yellow, orange or red, you’ve got a shot because those are absorbing light at frequency this laser diode emits.

Wood … you’re golden. This laser will etch like crazy, anything you like. Cutting thin soft wood also works. Go with solid soft woods or plywood. Composite materials like OSB or backer board have resins that are quite unpredictable.

Cloth, cardboard, foam, foam board … you’re almost certainly golden.

Focusing the G2 lens is critical. You need to nail it to +/- 0.5mm for the observations above to work. The visual method JTP suggests isn’t precise enough, go with their plan B and program a series of short lines separated by 2mm, vary the Z axis and etch your waste board.

Oddly enough, mine is MPCNC build No. 40 and 40 mm Z is the perfect focus on my build. Not surprising, I work with huge CNC machine tools every day. It doesn’t make sense to me as an engineer but I’ve observed that each has it’s own moods, personality and preferences. But, I digress.

It’ like the wild wild west out there with this configuration. Best to get your head around the fact early that there’s no magic Google phrase to give you the settings for you want to accomplish. Builds vary, materials vary quite wildly. Next time I’ll share how I’m approaching that problem.