Has anyone researched fitting CO2 Lasers?

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People have experimented with fitting diode lasers in the 3 watt range, and that is great. But has anyone experimented with fitting the far more powerful co2 lasers? You can get a complete Chinese 40 watt laser cutter for less than $400. http://www.ebay.com/itm/High-Precise-40W-CO2-USB-Laser-Engraving-Cutting-Machine-Engraver-Wood-Cutter-/200902245694?hash=item2ec6b4fd3e:g:nrUAAOSw2s1U0J02

It seems to me you could remove the co2 laser tube and components and mount them to the MPCNC, either using mirrors, as is common with co2 laser cutters, or just by mounting the laser tube straight to the spindle mount.

Has anyone looked into this or have any input beyond “You’ll shoot your eye out”?

I was hoping you guys wouldn’t figure out I’m crazy for a while, but I guess it was unavoidable.

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I want to do it. I was thinking like you are buy the cheap cutter, mount the tube down one of the table legs, add a mirror and you should be good to go, but then I always get to the “why take the other one apart”? If I need to start cutting large objects I will do it for sure. I can’t find a laser kit any cheaper than those pre built ones, that would be ideal.

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Cool! I’m excited you have thought about it, too.

A few notes on those Chinese cutters:

They have small areas, you mentioned that. Most of my laser work is bigger than 12". Even if it isn’t, its much better not to have to cut your material down to size just to fit it in.

They have TERRIBLE software and controllers. Like, there is really no worse software. Someday soon the Chinese are going to figure out we just want reprap, but not yet. The software generally borders on useless, vastly limiting what you can do and the operating systems you can use to control it.

Some thoughts on technical hurdles

I have never built a laser cutter before, so I wouldn’t be surprised if I was underestimating the difficulties.

The most obvious problem are the mirrors. I think that special mirror mounting printable axis brackets(if you know what I mean, the sliding part) could be designed or maybe even attachments to the existing brackets that hold the mirrors in adjustable catches. I think the biggest hurdle here is stability and straightness. I have no idea what kind of tolerances the MPCNC has on the straightness of those pieces.

The second issue would be containment. I dont know if you really want to operate one of those lasers without a case. Supposedly laser glasses make it safe but…I’m not sure. A question better left to someone with more knowledge. Also, cutters usually have air assist and always ventilation. I think both of those would work without a case, although not quite as well. Perhap the existing ventilation boots people have designed could be adapted.

I’d argue that there is a LOT of utility for this idea. If it can be proven theoretically possible, I would hapilly prototype it myself and even design parts in fusion 360 which I am learning. In that case it would help if I could get my hands on the cad files of the rest of the mpcnc parts. But first, I think we need more input from laser specialists.

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I’ve looked into those machines before. Very tempting, but I never have the spare $. Looking at the FSLaser cutter they make it seem like you need a ventilation system if you have a window or other outlet for the fumes or a filtration system. Could just be to sell people more stuff, but it makes sense at the same time. A simple vent system could be made with a bathroom exhaust fan and some dryer vent hose. Just make an acrylic or other clear plastic case and get safety glasses/goggles rated for whatever light is would put out.

I have no idea how to make all of the CO2 laser stuff work, but I’m sure someone here will figure it out. Would be cool to have the MPCNC down to a super easy quick swap system for different tool heads. I still see value in having a spindle and endmills for more 3d stuff, unless you mount 2 more axis on the CO2 laser and can move it at any angle as well.

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Just more info to the thought thread. Those mirrors need to be rock solid, or your beam alignment is going to be all over the place. Watching my router do it’s thing I can see the whole frame jiggling. It moves my whole table, which isn’t exactly light.

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Not really a good idea. Just get the cheap k40 and work your way around the issues.

It’s all about the tolerances. Just not going to get it on the MPCNC.

I have had a bunch of k40 lasers go thru the shop the last few months. Wonderful machines once you grok the operation of them, no need to butcher it and use it for parts. The bigger ones are relatively cheap too.

MPCNC is not really a machine I would count on to get 10 micron tolerances without maybe using some good quality chromed hydraulic shafting.

Rather it is a lower cost machine, suitable for wood working, aluminum machining where tolerances are not super critical, signage, and the like. Even CNC plasma looks like a suitable use as plasma seldom gives me sub half mm tolerances even on expensive pro machines I have used.

It possible to get one of these really dialed in, but it’s going to take a fair amount of effort, and a good dial gauge and you will need to be doing some re-adjustment quite often.

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I have thought long and hard about this myself too, I am contemplating 60 or 80 watt tube. If the laser tube is mounted to the main frame of the MPCNC even if it shakes it would shake as a unit. I have a couple simple ideas for mounting the tube. My build is 5’ x 5’ so the tube will fit along one of the Axis. Shaking should be limited as the moving mass would be much less then having the router hanging off the Z axis. Once I save the money to buy the tube, mirrors, lenses, power supply etc it will be an interesting adventure.

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Hello all, just wanted to revisit this thread a few months later as I am preparing to pull the trigger on this.

Mounting the tube to one of the rails is a really good insight and seems like a great way to reduce shake. Also, having very short legs would mean the shake can be pretty much eliminated, at least for my build.

I’m curious if it’s necessary to fully enclose laser cutters. Of course, all the store bought ones are enclosed. And it wouldn’t be impossible to build a lid system. I also don’t know if this setup with a 40w co2 laser would be significantly more dangerous than the diodes that a lot of people seem to be playing with.

Looks like you can use an old radiator as a bed surface: http://hackaday.com/2014/02/22/a-cheap-honeycomb-table-replacement-for-your-laser/

What seems for certain is that this is an idea a lot of us seem to have played with and I think maybe we just need someone to pioneer it.

It seems to me that some of the existing brackets could be redesigned with laser mount points on them. I could probably get away with doing it in fusion 360, and I’m open to that, but I’m curious how you feel Ryan about working with me to try to design them. You probably have the most resources and knowledge about this machine.

I think there are a few main parts which need to be designed. In the direction of the laser light, they are:

A tube mount for the laser, preferably direction on one of the legs, although im not sure how that would work without interfering with the movement of the axis.

An adjustable mirror mount attached or built into one of the stepper mounts.

An adjustable mirror mount in the center assembly that is NOT attached to the moving Z axis, but instead to the center assembly which doesnt move. Maybe you could pass the light between the two z axis conduit tubes.

A mount on the Z axis for the optic head thing.

Edit: also, I want to disagree with the idea that this machine is not accurate enough for laser work, on the basis that there are loads of people who are already doing laser work with it, simply with lower powered lasers. If it is accurate enough for rasterization, it is good enough for whatever else. It may not be good enough for very high tolerance work, but I’m confident it’s pretty good, especially when no forces are exerted on it like they are from CNC cuts.

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So last time we looked into this it came down to the price of all the parts, mirrors, mounts, tube, power supply, head. The least expensive way to get into this is buying a full unit from ebay, at that point just throw in a ramps board and call it a day. That is why I stopped looking at them. I even tried to get a group buy from one of my vendors that sells them, said we could get a slight discount but still cheaper to get a full unit from them than just the parts.

But…

If you want to try it I would love to see it! I would mount the tube up one of the table legs, bounce it 90 degrees off a corner block, 90 from a roller assembly, possibly straight into the laser head, depending on geometry ( it think they have a 90 built in), if not like you said 90 off the gantry into the head. The bad part is you need to be able to steer/aim the beam at every mirror, So reusing the the stock mounts or finding some nice printable ones would be cool. So it all comes down to your setup, each one would be pretty specific.

As for accuracy, I agree with you, as is it is good enough for most but if you were really trying to push some resolution boundaries using stainless steel rails would be all you would need.

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Hi…i am a new user here. As per my knowledge looking at the FSLaser cutter they make it seem like you need a ventilation system if you have a window or other outlet for the fumes or a filtration system. Could just be to sell people more stuff, but it makes sense at the same time. A simple vent system could be made with a bathroom exhaust fan and some dryer vent hose. Just make an acrylic or other clear plastic case and get safety glasses/goggles rated for whatever light is would put out.I have no idea how to make all of the CO2 laser stuff work, but I’m sure someone here will figure it out. Would be cool to have the MPCNC down to a super easy quick swap system for different tool heads. I still see value in having a spindle and endmills for more 3d stuff, unless you mount 2 more axis on the CO2 laser and can move it at any angle as well.

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I thought about those CO2 lasers for a while now, since they are not extremely expensive here in China (maybe around 100 bucks for the whole system I think)

In my opinion, the biggest problem will be the overal rigidity of the machine. My table is extremely sturdy construction, but it still wobbles a tiny bit because of the weight of the gantry whenever it moves fast. I think this will greatly affect the positionning of mirrors, and I’m not sure it will work fine.
I think The whole structure could be rigid enough just by adding 2 wood triangles to each of the 4 corners of the CNC. Then, securing the mirrors on the most rigid way possible.

Maybe I’ll try this later once the plasma cutter will be finished

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There’s another post here with someone using one of these lasers on the mpcnc. It does show some wobble, but I think it can be taken out. It’s actually working better than I thought it would.

Found it.

1 Like
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Yes that’s my post. I have more pictures and movies from this weekend.
I will update it tonight.

I’m open for any question if there are any.