CO2 Lasers....

Okay so The alignment and aiming are a bit more fiddly than I initially thought. Turns out you also need to really get the beam in the middle of the mirrors. This things has insane power and is almost useless without air assist (thought ahead and have one already). I am learning so much it is pretty fun.

So far the only real downside is the lack of an adjustable mount on the tube, and the crappy mirror mounts (no up and down adjustment so you have to bend things or use washers) it make alignment and aiming take a little more work but seriously not to bad so far. My tube is off a tiny bit so at the extremes my beam wanders about 2mm on the final mirror, not bad but I can do better with some shims.

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Time for an update, more than a month later.

Worth the money…Not really.

I bought it figuring all the easy updates I could do, make it giant, slap it on the MPCNC or the LowRider no problem, shoot I doubt it.

This is a whole new level of required accuracy, and as we all know out of the box it does not meet those requirements.

I have spent at least 20 hours getting what I want out of the alignment, 6mm MDF cuts. I will comfortably say that is the max.

Not sure how to structure this. So here is a random list of lessons learned.

1-I had to un-mount and turn the tube over as installed it holds a giant air bubble at the lens you are trying to keep cool.

2-You should never operate it above about 55% power, there is almost no cutting power to be gained but it adds a ton of heat and supposedly really kills the tube.

3-The bed clamp thing it comes with is pointless.

4-No way to adjust the bed depth other that shims, if you wanted to do a box lid or something you have some major disassembly to do.

5- Most of it is mounted to the sheet metal bottom so any movements and it is all out of alignment and skew. Even though it is on wheels I had to put it on a rolling rack.

6-The software is not as bad as people make it out to be other than they send you corel draw and a Crack to install it…Pirate much?

7-Scorchworks inkscape plugin is insanely awesome.

8- Air assist is a must for deeper cleaner cutting and etching, without it fire is a certainty, I printed my own nozzle.

Now the two large issues.

9-The ventilation thing is impossible. I have taped every hole shut from the inside and out, including taping it closed before turning it on, my lungs are killing me right now. I have no idea where this crap is leaking from but I am sure I have lung cancer in my future and that is after a 4 minute cut. I have added a fan as well, so the big one it comes with(with the back sealed with tape) and an inline duct booster fan, all duct taped shut hanging out a two story window. I’d like to think I am no dummy but this thing spews crap into the air and I don’t know where from. I tried controlling the inlet of fresh air from small holes to the lid being slightly open, It still smell like I had a boyscout jamboree kumbaya bonfire in the office. And I am not lying my lungs hurt…again.

10-Lenses, alignment, ect. The lenses/mirrors come filthy, I had to chip stuff of with my finger nail. They obviously align it by sticking tape to the lenses and burning it. They are no where near alignment when you get it. The lenses/mirrors that come with it are pretty bad and not big enough. The lens has a very small aperture when placed in a 45 degree mount, anything but perfect center alignment will clip the beam and severely limit your total power at the cutting point (the beam is actually very large and only focuses/culminates at the final lens. The 1st and second mirrors are on hand cut sheet metal mounts with no way to align them in the z axis other than bending or shimming the mount screws. The 3rd nozzle mirror has no alignments other than rotational in it’s hole and forward and backward (Yaxis). So I ended up with a low nozzle mirror that was angled in, yup shims and tape on the mirror to angle it and it is still a few mm off.

Doing it yourself is a better option, you need the tube, power supply, mirrors and lenses, and mirror lens mounts. Lots of site documenting how to use a aduino based board to control them. From there a few 3D printed parts in a custom box with some knock off hiwin rails would be a much better laser. Adding this as is to a mpcnc is not the best option I don’t think. If you got a set of larger mirrors/and lenses it could work but laser alignment in not laughing matter. You will be doing it all yourself anyway might as well start from scratch.

Again if it is just for etching, it works great, cutting is a whole new ballgame.

So for 6mm MDF I cut at 55% power at 5mm/s with air assist. I easily do the same on either cnc at 8.3mm/s but it takes two passes as I do a rough and finishing pass, the laser is slightly faster, but…6mm is the laser absolute max and it has a heavily modified bed to cut 332mm wide by 192mm long the lowrider is 8’x4’. I really hoped this would help increase my production.

 

Thanks a lot for the feedback.

I think that most of the issues you mention are related to the chassis itself, so it could solve most of your problems to take it apart and assemble it either on the MPCNC or on the LowRider.

It will also give you the ability to have a Z axis, so potentially deeper cuts.

I really want to try doing that, but it’s just a little bit too expensive, plus I’m not sure how I could safely add this to my table design.

Yup Dui, I have a bunch of the knockoff Hiwin rails waiting for a rebuild. I think I want to skip the included mirrors and stands/mounts and just get the next larger set. To make things worse it comes with fairly large mirrors but then puts them in a holder that covers up about 1/3 of them, I wonder if 3D printed holders would hold up, they get warm but not hot…hmmm.

I somehow missed the subscribe button on this thread. I suck at technology sometimes.

I hope you are having fun/had fun with it. I have a college buddy that works in a laser physics lab. Their goals are much loftier, so they really have to dial their lasers in, but they use these giant optical tables, that are solid metal and have precise mounting holes in them. If I ever get to the point where I can try something like this, I think I’ll kidnap him for a few hours and let him tell me WTF I’m doing wrong.

So cool though. All that adjusting and errors get worse at larger spans, maybe try just shrinking everything at first (have you ever given advice like that? :smiley: ).

Do you watch Tech2C? He strapped a 2.5W laser to a hyper cube and he’s been getting pretty good results, even cutting through some plywood (6mm, I think?) and black acrylic.

I have it working pretty solid now, but the frame is welded together and it is skewed (of course). I am trying to decide if it is worth doing a custom build or just getting a different machine now that I know what I am looking for.

Well…of course I am going to build a custom machine but I also think there is value in recommending something better for people as well. There is what looks to be a really nice package at http://www.lightobject.com/High-Speed-Desktop-40W-CO2-Laser-Engraving-Machine-wZ-Table-P1061.aspx It is $3k plus shipping but it will be half the price of any other laser and they seem to have all the right parts in this one.

I am thinking of some flat parts for a new set of parts and before I start designing them I have to know I can produce them reliably.

The $3k machine seems like a good deal to you… That’s a dose of reality. I guess I won’t be burning holes in anyone’s eyeballs anytime soon.

I am trying to price it if I was to do it again. Like power supply, cost of a rambo board, tube, mirrors mounts, fan, pump ect. To see If I can do something great for under $800, for the $360 this cost plus all the other stuff I learned a lot and it was a very inexpensive leason, and I still have a wonderfully functional tool. I do think I can get something together so more can try it. The mpcnc is to heavy for the speed at which this works when etching, it can cut fine but this thing etches great at about 150mm/s…

I think I will build a box and use some unistrut for the inner skeleton. I have a few ideas for that unistrut as well…mpcnc pro?

Unistrut, adult tinker toys!

I went to a few hardware stores. Some of that unistrut is nasty some is okay. I don’t think it is worth using. What a bummer it is so cheap and already has holes in it. I’ll have another look but maybe the gold stuff is the good one, dang it now I don’t remember.

Most of the unistrut I get is from Menards. Though I’ve found good stuff at Lowe’s too.

What model of laser you have actually? More pictures? I got the SH-G350 (30 x 50 cm working area), 50w. With 40w I assume you have the “K40”, with no adjustable Z axis. This thing is bad to start with, might want to give a try with a bigger model. My machine did cost about 600 USD (1200 at first, then the seller refunded me 50% because I had problems running the machine).

I’m using this as tube holders, https://www.thingiverse.com/thing:420853, there’s mountings for the K40 too. But this machine will still be crap tho.

The larger machines (basically ALL machines other then the K40) use a better and more comfortable controller, using other software (RDWorks). This is like day and night…

I think every tube (not only looking at its size or watts, just every tube even same size/wattage) is different, usually you go with an amperemeter to not wear out the tube too fast -> http://lensdigital.com/home/?p=1453

Most other points in your post just exist because you went with the K40 :(, guess you figured by now since you already posted a link to a 3k machine without all those disadvantages. You’re from the US right? Are there any legal restrictions you have to meet to operate such machine? Here in germany, me as a non-commercial person, it’s not even legal to buy/operate my machine (please don’t tell anyone! jk). The 3k machine is probably not THAT much better (cutting/engraving wise), but it’s a smoother case and maybe some security improvements (like triggers/switches that shutoff the machine when you open the lid while the machine is operating and stuff like that - nothing a chinese laser has).

I’m not advertising or affliated with, but if you need parts, I bought alot so far (spare parts) for my laser at cloudraylaser.com (through aliexpress).

@your cancer/lung concerns: you did not lasercut polycarbonate, right? Just to make sure. Yes even the correct type of acrylic smells nasty, but PC (polycarbonate) is a whole new level in smell…

That might go for wood, but don’t forget lasercut edges of acrylics are just wonderful (because clear). I did not cut acrylics with my MPCNC yet (I also dont intend to), but I doubt the edges will be so perfect.

Yup a K40.

Yeah definitely a case of a little more initially gets a lot better machine. I really didn’t care my intention was to rip it apart and slap it on an MPCNC or the Lowrider anyway, maybe even a ZenXY frame. Now I think that might not be possible but I haven’t completely given up yet. I was pretty intimidated about what was actually inside of them…no big deal. Luckily it is an R&D expense for me so I hope for it to benefit all of the user here in some way or another, cheaper parts or a more versatile CNC, win win really.

No, no PolyCarb. I do have some clear acrylic, I can’t wait to try it out.

 

The biggest advantage for an allted™ lasercutter I see is making everything highly adjustable. Theres a lot of people with the bigger machines (non-K40, so I’m talking about the 30x50cm and 60x40cm machines) to make everything square. Most machines I have seen so far are so much out of square, if you just pulse (testshot) theres a high chance everything is so much misaligned, the laser won’t even hit the workpiece at all.

The tube needs to be perfectly aligned and parallel to the work place. Other than that, looking at my mpcnc, its probably more then rigid enough to hold some leight weight mountings for some 1-1.5 inch mirrors. This could be a nice add-on for the mpcnc, and not a whole new/different machine.

Only problem I see, beside security measurements, are the fumes. Vaccum will be required, otherwise the whole mpcnc will be covered in a sticky mess sooner or later.

This is for sure in the back of my mind. I am really just having an issue with a nice sturdy base to build on, after that we have all kinds of options. I have spent too much time looking for some cool cheap building materials other than conduit, but really conduit is so cheap and easy it might make for a great frame/base. For the motion stuff, it needs to be light, the laser is strong so it can move really fast. I think that part would be best to just use the cheap import hiwin style. I have a stack here that I will play with but they need to be re-tapped as the threaded holes are not good. That made me stop using them for a while but I am reconsidering.

I think one of the coolest things about the possibility of putting a laser that powerful on a homebuilt machine is that you really need rigidity mostly to hold the weight of your equipment since you aren’t physically cutting anything with a spinning bit, unless you want pretty nutty speeds.

What’s the toughest material 40W can get through? My only experience with a laser is knowing you can slam through 1/16" aluminum at 300-400 IPM at 3200W and 3/4" steel a fair bit slower. I’ve been thinking about adding a laser option to my machine but I don’t know if it’s worth just having it for engraving if I can already do that with engraving bits lol.

Have you messed with 8020 or a similar aluminum extrusion at all? It obviously won’t be as cheap is conduit but being modular you might be able to make a pretty damn rigid machine a lot easier. Need the rigidity and power to have those crazy rapids speeds. Trumpf laser at work rapids at something like 1000 IPM, can’t remember off the top of my head but I flinched the first few times I saw it lol.

A lot of rigidity is need for the accelerations as well. Moving fast means starting and stopping fast without ringing or shaking it apart.

So far I can do 1 pass pretty easily through 6mm MDF at about 5mm/s with air assist. I don;t think it can go anyfurther in MDF in a single pass, but I haven’t tried. Not sure about other stuff yet.

I’m not a fan of 80/20, I mean it is awesome and does make things really easy but it is really expensive and you have to have it shipped which costs more than the material sometimes. Maybe if I could get it locally. I did submit a quote for my own die for some custom extrusions this morning though…hmmm.

The craziest part of the laser is it can be any size, seems crazy that these things are being sold in a giant metal box and the work space is 200x250mm, I took mine straight apart and have 350x290 now but see no reason to stop there. Actually seems to be easier to align the larger it is.

 

“Safety Squints”? “Chooch”?? I think I’ve come across another AVE/BOLTR fan! :smiley:

Isn’t everyone a fan?