Converting a CNC router to a lazerengraver/cutter?

[Crawler374]

Hey guys, I recently built a 4x4' router table. I like the machine, but i think i will like a lazer cutter much more. I tend to need real sharp angles and points and the router leaves every corner round. I also seem to only cut 2D parts with my machine...

I have read up that you can get a Co2 tuber and a diode to make your own, but thats about as far as i understand.

I plan to cut steel, aluminum, wood, and acetal (delrin) all materials will not exceed 1/8" besides the Acetal at 1/4" at the most.

Can anyone give me a link, list, or details of what i need? I am currently running Mach3. can this be used? what about turning the lazer on/off? how will i go about doing that? how deep does a cirtain lazer cut? will i need to design a new table to keep the CNC table from catching fire?(MDF). I'm assuming a Z axis is not needed? true? Thanks for anyonethat can answer these questions

[zax15uk]

I would suggest you already have the correct tool for your varied materials.

To cut the metals with a CO2 laser would require several hundred to multiple kilowatts of power. The wood and acetal would be easier, an 80W would be sufficient.

Even accepting the above, you would still need to redesign the machine (possibly modify the chassis) and add mirrors/optics. The Z-axis would be required to focus the beam by moving the lens up/down.

Yes, Mach3 would work - it can switch the laser using one of the outputs and adjust power with PWM or an analog voltage convertor.

Zax.

[Crawler374]

Originally Posted by zax15uk I would suggest you already have the correct tool for your varied materials. To cut the metals with a CO2 laser would require several hundred to multiple kilowatts of power. The wood and acetal would be easier, an 80W would be sufficient. Even accepting the above, you would still need to redesign the machine (possibly modify the chassis) and add mirrors/optics. The Z-axis would be required to focus the beam by moving the lens up/down. Yes, Mach3 would work - it can switch the laser using one of the outputs and adjust power with PWM or an analog voltage convertor. Zax.

okay. I can sacrifice not cutting metals. No big deal. So i would need an 80W diode and a Co2 tank? How do i know what kind or size tank i need? are they all the same and do the same principles?

What are mirrors/optics? I can have the Z axis manual, correct?

[lumberjack_jeff]

Originally Posted by zax15uk I would suggest you already have the correct tool for your varied materials. To cut the metals with a CO2 laser would require several hundred to multiple kilowatts of power. The wood and acetal would be easier, an 80W would be sufficient. Even accepting the above, you would still need to redesign the machine (possibly modify the chassis) and add mirrors/optics. The Z-axis would be required to focus the beam by moving the lens up/down. Yes, Mach3 would work - it can switch the laser using one of the outputs and adjust power with PWM or an analog voltage convertor. Zax.

You just alluded to something I hadn't realized. The business end of the machine focuses the beam to the desired cutting location.

To what degree does this mitigate the safety problem of the unfocused laser bouncing from mirror to around the machine/shop?

Until now, I had thought of a DIY laser as akin to DIY x-ray machines; a job best left to pros.

[kewlkiwi]

Originally Posted by lumberjack_jeff You just alluded to something I hadn't realized. The business end of the machine focuses the beam to the desired cutting location. To what degree does this mitigate the safety problem of the unfocused laser bouncing from mirror to around the machine/shop?

The unfocused beam, traveling around via the mirrors, is still pretty hot - on mine it's about 0.25" diameter - so putting your hand in the path, while not as bad as when it's focused to a point, is still not something you'd want to do.

Bob

[zax15uk]

Crawler,

I suggest you do some research - perhaps take a look at the excellent Sam's laser FAQ http://www.repairfaq.org/sam/lasersam.htm .

A diode laser is a self contained solid state device, this is totally different to a sealed CO2 laser tube or a flowing CO2 laser. With a diode laser you can mount it on the Z-axis and have a lens to focus the beam. A CO2 laser would require a stationary tube located along the side or rear of the machine and a set of mirrors to allow the beam to travel to the Z-head and final optic.


Jeff,

The unfocused beam from (for example) an 80W laser would usually be 6-8mm's in diameter, the power density is still sufficient to cause skin burns, ignite materials and blind. Yes, it's dangerous! Any laser should be contained in a safety enclosure, or behind laser shields. In the case of an open structure the laser operator needs eyewear and safety training. The reflected beam can be just as dangerous and of course many lasers are UV or IR so invisible (this means your eye's natural blink reflex will not protect you).

Safety First, unless you're a Mike Rowe fan in which case Safety Third

Zax.