K40 CO2 Laser - any good?

[My Old Landy]

The S1 hasn't even arrived yet and I am already thinking of adding a CO2 to the collection!
They are only £565 at the moment and seem like a good deal.
I know a few on here have got one and wonder if they are any good?
Cheers for any advice.

 

[My Old Landy]

@JMS1972 do you still have one of these K40's?
I may wait and save up for a larger machine if they are not up to much.

 

[jmp49]

Ive had a K40 for about 4-5 years now, it still works fine and I'm on the original tube but I dont use it as much recently. Its a bit triggers broom because I like to tinker with things.
I am always careful to let it circulate before use to purge any residual air out the system as theres a bend on the tube water inlet at the top that sometimes traps bubbles in it, and I've added a air pump from a fishtank with a blower to keep the laser path free of smoke (air assist helps a LOT with flammable material like thin card etc), and I cut the fume extraction nose out with a angle grinder and side mounted a big extractor blower to suck the smoke out more efficiently & I vent this straight outside via a vent through the wall behind it. This also gave me more Y travel too. To go even bigger I'd have to change the linear axis rails/belts for longer ones, which I've considered moving all the electronics and extending the bed to the entire width of the machine but its mostly big enough for what I need tbh.
For cooling I have a pond pump in a big bucket underneath that has enough thermal mass to absorb the heat generated without needing a chiller etc. I just run straight distilled water in it and top it up when needed.
My case has tape over the vents on the lid as these used to leak fume into the room, now it sucks air in through the side vent where the electronics are & cool them better, and it doesnt leak smoke in use.
Another mod I did was to throw the original bed away and fit a honeycomb one. You'll find a laser pointer holder + blower tube holder that goes on the laser head on thingiverse etc to 3dp.
Amazingly somehow I'm on the original mirrors still, I see a lot of people have upgraded them to higher quality ones but until they break... Also the glasses I got with it I was unsure of so I bought some quality ones of the correct wavelength...
For software I use scorchworks K40 whisperer laser software, its open source and I dont trust the oem software which was terrible when I first started with it. For laser design etc, draw in favourite cad, bring that over into inkskcape and colourise the lines red or blue for different laser powers (cut/engrave in the same part) and squirt it over to the cutter. https://www.scorchworks.com/K40whisperer/k40whisperer.html

For what I've done with it, well, plastics, ply, marking on painted metal objects, lasered designs into glass, cut gaskets out etc. Its small but capable. It can't engrave metal parts as the laser is the wrong frequency and not powerful enough. Ive tried the moly/graphite spray trick to ablate the marking into the surface but its still not that great...
I also use it to prove cad designs in ply before committing them to aluminium etc on my machining centre proper. Footrests, brackets etc. Ply is cheap and its a great help to be have the proto in your hand when its not expensive to change your mind...
Its just small enough to have in a office or a room in your house handy for a quick cut but big enough to do stuff in. Any bigger and It'd have to be outside in the workshop then I'd have to faff about running antifreeze and worrying about it freezing in winter.
Just my direct experiences. Its well paid me back for what I paid for it.

 

[JMS1972]

@JMS1972 do you still have one of these K40's?
I may wait and save up for a larger machine if they are not up to much.

Yes I still have mine might consider selling it as it doesn't get much use. Make me an offer

It will do 3-4mm plywood/MDF and acrylic. I use inkscape and K40 whisperer software all freeware

 

[My Old Landy]

Yes I still have mine might consider selling it as it doesn't get much use. Make me an offer

It will do 3-4mm plywood/MDF and acrylic. I use inkscape and K40 whisperer software all freeware

I am interested it is the acrylic side that I want to do. I will PM you

 

[My Old Landy]

Ive had a K40 for about 4-5 years now, it still works fine and I'm on the original tube but I dont use it as much recently. Its a bit triggers broom because I like to tinker with things.
I am always careful to let it circulate before use to purge any residual air out the system as theres a bend on the tube water inlet at the top that sometimes traps bubbles in it, and I've added a air pump from a fishtank with a blower to keep the laser path free of smoke (air assist helps a LOT with flammable material like thin card etc), and I cut the fume extraction nose out with a angle grinder and side mounted a big extractor blower to suck the smoke out more efficiently & I vent this straight outside via a vent through the wall behind it. This also gave me more Y travel too. To go even bigger I'd have to change the linear axis rails/belts for longer ones, which I've considered moving all the electronics and extending the bed to the entire width of the machine but its mostly big enough for what I need tbh.
For cooling I have a pond pump in a big bucket underneath that has enough thermal mass to absorb the heat generated without needing a chiller etc. I just run straight distilled water in it and top it up when needed.
My case has tape over the vents on the lid as these used to leak fume into the room, now it sucks air in through the side vent where the electronics are & cool them better, and it doesnt leak smoke in use.
Another mod I did was to throw the original bed away and fit a honeycomb one. You'll find a laser pointer holder + blower tube holder that goes on the laser head on thingiverse etc to 3dp.
Amazingly somehow I'm on the original mirrors still, I see a lot of people have upgraded them to higher quality ones but until they break... Also the glasses I got with it I was unsure of so I bought some quality ones of the correct wavelength...
For software I use scorchworks K40 whisperer laser software, its open source and I dont trust the oem software which was terrible when I first started with it. For laser design etc, draw in favourite cad, bring that over into inkskcape and colourise the lines red or blue for different laser powers (cut/engrave in the same part) and squirt it over to the cutter. https://www.scorchworks.com/K40whisperer/k40whisperer.html

For what I've done with it, well, plastics, ply, marking on painted metal objects, lasered designs into glass, cut gaskets out etc. Its small but capable. It can't engrave metal parts as the laser is the wrong frequency and not powerful enough. Ive tried the moly/graphite spray trick to ablate the marking into the surface but its still not that great...
I also use it to prove cad designs in ply before committing them to aluminium etc on my machining centre proper. Footrests, brackets etc. Ply is cheap and its a great help to be have the proto in your hand when its not expensive to change your mind...
Its just small enough to have in a office or a room in your house handy for a quick cut but big enough to do stuff in. Any bigger and It'd have to be outside in the workshop then I'd have to faff about running antifreeze and worrying about it freezing in winter.
Just my direct experiences. Its well paid me back for what I paid for it.

Thanks for the information, that is really helpful. I am mainly interested in cutting acrylic as the diode S1 won't do that.

 

[My Old Landy]

Just as an update, with thanks to @JMS1972 I am the proud owner of a K40. It has taken a while to get the space sorted but it is in place now

 

[jmp49]

Nice, I'm waiting for some longer drive belts & rods to arrive, and mines coming apart for some more mods. I'm moving the psu & board outside the case to its own housing, removing the internal divider, and putting longer rods and drive belts in and moving the right hand linear rail to inside the psu section and fitting a full width honeycomb bed, giving a X of the full width of the machine. Still debating if to swap to hwin rails on rexroth or not inside like this chap did. I already cut the nose off that restricts bed size and moved the extraction fan to the other side. Alignment might be a challenge...

Write up here

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[rcx132]

I have one. It needed a rebuild to fix earth issues, bad assembly. Added safety switch, better table, and alignment pointer. It's been surprisingly useful during my buggy build. Just made dashboard from it and about to make electrical bus box.

 

[rcx132]

I used a simple recoil hose for the air blower, a lot less work than the elaborate folding systems people go for and works fine.

Expanded alu works OK for table if you don't want to pay for honeycomb. Honeycomb is good for fine work as there's less beam reflection.

I tried laser pointers to position the cutter but they all got in the way and eventually fell off. In the end I made a ring light that shines down the laser channel making the marker totally integrated. See pic.

The K40 is pretty big and takes up "real estate". But I built a box to go over it so the space is re-usable when the laser isn't in use.

The lasers have space for a kill switch in case someone opens the thing during use. But most don't have the kill switch fitted! I have kids to I fitted one.

I wouldn't trust the orange safety window. Laser safety windows usually have type approval markings and state the laser frequency they protect against. The K40 doesn't. I use laser glasses which I bought from these guys as they are US certified. Guess what.... most laser glasses are made in China and when I checked many of them had faked safety certificates!!! safetyprotectionglasses.com

The laser is quick to use and that's why I've kept it. It takes minutes to knock up a design and send to the cutter.

Mines been reliable except for a failed power supply. I fitted a better cloud ray supply. I don't use distilled water as it goes off. I'd rather just replace the tube more often. The only issue I have now is that the mirrors seem to break down. Is this normal anyone ?

 

[jmp49]

I put laser pointers right on the head, along with a air assist tube, which is just done in floppy fishtank tube with no coily elements. It seems to cope.
I printed a mount off for both because it was done before nozzles with the air assist integrated appeared, I keep wondering if I should change it but its been solid for so long I just left it alone as it did the job, untrimmed ziptie waving around included. Its a tool, as long as it works. Also impressed there's still a tiny bit of the blue plastic shipping film on the laser carrage plate hanging on for grim death since it was bought on ebay in 2018
Ignore the corrosion, during Covid it was heavily employed cutting mask wallets out of acetate and the fumes caused everything to corrode weird. Pretty glad I put the extra venting in to outside after seeing that! Its also one of my drivers to expand the cutting area as the rails etc are also like this.



If you purchase lightburn software, you can integrate a camera onto the k40, and drag and drop the cuts onto the part of the bed visible on the camcorder so no need for alignment marks. I think with a standard control board you have to run a intermediate software shim, or change the board itself to a lightburn compatible one. I use k40 whisperer still, so I haven't bothered looking into the specifics, it just does what it does quickly currently.

 

[My Old Landy]

I used a simple recoil hose for the air blower, a lot less work than the elaborate folding systems people go for and works fine.

Expanded alu works OK for table if you don't want to pay for honeycomb. Honeycomb is good for fine work as there's less beam reflection.

I tried laser pointers to position the cutter but they all got in the way and eventually fell off. In the end I made a ring light that shines down the laser channel making the marker totally integrated. See pic.

The K40 is pretty big and takes up "real estate". But I built a box to go over it so the space is re-usable when the laser isn't in use.

The lasers have space for a kill switch in case someone opens the thing during use. But most don't have the kill switch fitted! I have kids to I fitted one.

I wouldn't trust the orange safety window. Laser safety windows usually have type approval markings and state the laser frequency they protect against. The K40 doesn't. I use laser glasses which I bought from these guys as they are US certified. Guess what.... most laser glasses are made in China and when I checked many of them had faked safety certificates!!! safetyprotectionglasses.com

The laser is quick to use and that's why I've kept it. It takes minutes to knock up a design and send to the cutter.

Mines been reliable except for a failed power supply. I fitted a better cloud ray supply. I don't use distilled water as it goes off. I'd rather just replace the tube more often. The only issue I have now is that the mirrors seem to break down. Is this normal anyone ?

View attachment 455927 View attachment 455928 View attachment 455929

Thanks for this. I totally agree about the glasses. I have thrown away the ones that came with my two cheap lasers. @JMS1972 gave me a good pair for the K40 frequency. I have also purchased hopefully a good pair for the diode lasers. The IR in the F1 came with glasses that have the frequency and certificate number. I don't know if they are fake but to be honest I don't look at the light except via a camera.

 

[jmp49]

The only issue I have now is that the mirrors seem to break down. Is this normal anyone ?

I'm on the original 2018 mirrors still. I keep reading about "high quality" alternatives improving performance, but while they work I'm ignoring it.
The problem being for me is that anything chinese "high quality" often turns out to be crap compared to what something was shipped with and there's no real way to make sure you can pay more and get a better product because half the drop shippers resell the crap quality ones as high quality to make more money as a sort of idiot westerner tax, and the original mirrors must have been reasonable quality to last all this time.