Laser on Max 1 or cartesian CNC machine?

[Captain Starfish]

Still not sure what fit of insanity possessed me but in a few days I'll be the owner of a 3.5w 445nm laser. It's a diode in a brass tube with a collimator lens and a power supply. So I need to make up an ali heatsink and mounting bracket for it, and wire it into control circuitry etc but it's nothing major.

The question: do I put it into my Max, or into an OmioCNC x6-2200L CNC machine?

I'm kinda leaning toward the CNC machine at the moment:
- Mach3 drives the engraving/vcut toolpaths easily;
- Fluid cooling is already running to the spindle head so I could make up the heatsink to be liquid cooled;
- CNC machine sits in my workshop rather than the study where the printer lives, so fumes aren't such a drama;
- Much bigger bed on the CNC, rather than the printer which has a lot of height which I'll not use for this application.
- CNC driver board already uses PWM to drive the spindle, if I swap from the VFD to the laser PSU I get power control.

But can anyone think of a reason to chuck it on the Max, apart from the joy of freakin laser beams?

I know the correct answer is buy a 2nd one and set both up.

[Xenocrates]

I'd go with the CNC. I love the max as a printer, but it is not something I would laser on. While 3.5W shouldn't be enough to cut the melamine, I prefer having a metal casing between me and laser systems (And either a treated glass or poly-carbonate window for the view). Unfortunately, you don't have a shell built into that CNC machine (Which is something I do not like about most of the cheap ones. Having seen the dents left when some tools/parts let go in a Haas, I never want to deal with an unenclosed CNC (Even though I do have the door open most of the time, I can hide behind the rest of the shell))

I do recall you built a PC enclosure for your max though. So if that's true, and you haven't built some form of enclosure for your CNC (You really should), that might be a point in favor of the Max (as PC will absorb enough of that wavelength to make it safer, even if it won't absorb as much as if it were IR).

I would also buy a set of laser protective shades of the correct wavelength. They are expensive (~90$ USD if you don't buy chinese ones, which I'm not sure I trust. You need at least OD4 at 445nm to be protected from your laser.) http://www.phillips-safety.com/laser-sa ... n-ktp.html for example. While it's likely more than you spent on the diode, I would not mess around with lasers without the correct eyewear (Especially DIY projects like this in unenclosed chassis). There is a reason that many many manuals say "In case of accident, do not look into laser with remaining eye"

[Eric]

Unless you already have an exhaust system set up for your Max, I'd say moving the fumes out of the house would be the deciding factor.

[Captain Starfish]

Cheers guys. Xenocrates - when I got the OmioCNC, I made two parts with it sitting on a table in the workshop. I cleaned up the ghastly mess left behind as best I could with brush and vacuum, but for a week afterwards every time I walked down there I'd come back with metal splinters in my feet. So I made an enclosure for it. The acrylic sheet I used to enclose the Max was the remainder of what I used for the CNC.

For the area involved, buying proper filter film to line the CNC enclosure would cost more than the CNC enclosure and the CNC in it - stuff is expensive! I've bought a couple of pairs of 445nm-unfriendly safety glasses to go with it and some of the first things it will be doing are warning signs at the workshop entrance and by the machine to (hopefully) give pause to any surprise visitors. From what I'm reading, even at 3.5W the reflection from the spot if it hits metal is enough to do permanent damage.

The other thing that's pushing me to the CNC is that I can leave the thing permanently mounted to the side of the spindle, there might even be room in my breakout board to add a switch for the control so I can g-code select which I'm using from the CAM package. Mill and engrave in one op? That'd be cool.

[Captain Starfish]

I think the suggestion was a good one, looking back.

Easy to mount, no worries with only 3.5w of cutting/scorching the aluminium bed (garolite may have been a different story), Mach3 is a much more natural fit to the cutting/engraving stuff than Repetier firmware would have been. Thanks all.

Finished the initial install yesterday, just need to sort out the PWM output for output power control.