Laser cutter/engraver

[Leo.G]

I'm looking to possibly build a 40 Watt co2 laser cutter/engraver. This will be a very slow project as I acquire the bits and pieces I need over an extended period of time (pension). Were I to have the spare $5K+ laying around I'd just buy one but I don't. The unit will be capable cutting of 600x400 sized material.

Does anyone have experience building such a beast and any pointers on what to do and what not to do?


Thanks!

[iborg]

Hi Leo


I have bought a little CNC machine from Vevor, just a toy really, but, gives a good idea of how things can be done. Also, slowly building something bigger and better.



The reason I mention this, is that Vevor also have laser engravers.


This link is to one in particular. https://www.vevor.com.au/laser-engraving-machine-c_11141/vevor-15000mw-engraving-milling-machine-3040-laser-engraver-kit-for-wood-plastic-p_010629102294


While this is smaller and less powerful than you are after, I believe it will be possible use the same electronics on a bigger frame and swap the laser for a more powerful unit.


Of course, you would also want to build a box for it, with an interlock for the power for safety reasons.


There are a fair number of forums out there, so happy hunting.


Philip

[Leo.G]

Thanks Philip!
I primarily want it for cutting acrylic but for a start I want to play with just burning lots of little indents in acrylic, CNC would be great.
The majority of the frame and electronics I can do, or pick up reasonably cheap. Though a smaller unit may do for what I want for a start.
Light guide plate for back-lighting images is what I want to do, to purchase the plate already done is dearer than stripping out a decent quality light board (copy/tracing board, whatever they call the things).



There's an interesting write up here:


https://hackaday.com/2023/03/13/a-hackers-introduction-to-diy-light-guide-plates/

[iborg]

Hi Leo


That looks really interesting and is something I was not aware of. I'll be interested in knowing how you go with it.


One of my, too many, projects, is converting an old Gravograph engraver to a real real CNC machine. If I manage to get it running the way I want, swapping the CNC motor for a laser should be simple enough. Then I would also need a box and interlock.


Good luck


Philip

[Leo.G]

Finding a 50 watt co2 laser tube for under $100 new may yet be the key and my son found one in Aus with free freight.
Buying bits and pieces as affordable is what we'll do, a nice PSU yet to be found but we'll search Aliexpress for multiple things like mirrors and power supplies. NEMA steppers aren't overly expensive there either and there are some good quality units available (and some very cheap ones, no idea how they work.


The laser diode type machine you linked to won't cut acrylic, I need a co2 laser for that purpose.
My son suggested trying thick steel under acrylic sheet and a plasma cutter which I own but I think it would more melt the acrylic than cut it cleanly.

[LonelySpoon]

If you plan to cut acrylic you need really strong fume removal.

Not just for your health but for the mirrors.

Cost me $50 to learn this...

Also, be sure whether the 40 watts is the delivered energy or the input energy, for that price.

Happy cutting

Neville
LSO

[Leo.G]

I had typed a reply and hit the STUPID back button on my mouse on the end of the keyboard and it disappeared, I HATE computers, I think I HATE my current mouse worse, never had the problem with any former mouse.


Neville is there any specific form of fume extraction you recommend?
Is it a filtered system required?
I would imagine it would have to be filtered on the output or the room would become toxic fast.


My main experience with acrylic was making display cases for shops (photography shops) back in the early 90s. I was using chloroform to provide the clear, seamless joints (only way to get such joints at the time) and even with fume extraction it created problems breathing in the fumes. I had the materials cut and bent if necessary by my supplier at the time, I didn't have provision to do either and it wasn't costly to have it cut and bent compared to purchasing the required equipment (it was just something I did to help friends with photography stores, not a business as such).


The laser module itself I'm not sure on the specs, I have no experience with this type of laser head. I've played with a few laser diodes for other purposes over the years but nothing like this.


https://www.vevor.com.au/laser-tube-c_11139/laser-tube-co2-laser-tube-50w-800mm-for-laser-engraving-and-cutting-machine-p_010830114190


Maybe not sufficient for my overall end design (when I get there) but a cheap way to get my foot in the door.


I'll search for forums specific to the build and do a lot of reading and hopefully learn from the mistakes (and accomplishments) of others.

[iborg]

Hi Leo


I second Neville's comment about the laser power. For this and your main power supply, I would not try too much to skimp on price or quality.


Too often, the specs for cheap units are over hyped. Personally, I use Meanwell power supplies when I can.



Philip

[LonelySpoon]

Leo,
I have to admit that the unit I have is a 100W full industrial system.

By that I mean it came with a humongous fume extraction system that I vent to the outside, a proper refrigeration system to cool the tube water, and a small blower to push air over the lens area to keep it clean.

(This was my big retirement present to myself)

I'd suggest something at least to the standard of welding fume removal, with filters as appropriate. I believe there are also systems for use by nail salons-they're quit fum-ey.

I'd also suggest the refrigeration pathway. Some people simply use a bucket of cold water and feed the pump lines through that, but it quickly warms up and efficiency drops off.

Finally, the tube you linked to is peak rated at 50W. If you use it at that power, it probably won't last long. My branded '100W laser' has a 120W tube, with the instruction to only use as much power as you need.

It is more likely that the 50W will give about 40-45, and the 40W about 30-35.

Not wanting to dissuade you at all, it's a great project. I've made a CNC metal milling machine, a CNC foam cutter (for wings) and a CNC router myself.

Gives you a great sense of achievement when they produce something!

Cheers,

Neville

[Leo.G]

Thanks again Philip and Neville!
I'd love a system like yours Neville but don't have the money. Ideally, I will only be using it for cutting acrylic up to 4-6mm maximum and messing with burning little dots in the back (light guide plate). Cutting and polishing the edges I can already do without the laser (varying stages of wet and dry and a good application of Silvo does wonders, Brasso for finer scratches).
I already bought the tube, saw it cheap and decided I could afford that as a start and build something around it.
I'm quite familiar with welding fume extraction, in my late 30s I studied fabrication engineering (welding). I've also looked into the water chillers (also used in welding machines), that came up while chatting with my son last night, he'd seen them recommended.
While basically cheaping out and doing this on a very restrictive budget (disability pension) time isn't an issue, I'm in no rush.
I have a milling machine at my disposal (when I finally get to welding a stand for it) and a lathe, the milling machine isn't CNC but that is in the planning stages too.


I'm also familiar with the concept of purchasing decent power supplies for projects like this, I originally had a background in electronics but added electrical, welding, machining, hydraulics and pneumatics, IT and few other bits and pieces with a former desire to get into mechatronics. My health doesn't particularly lend itself to a lot of what I'd like to do.

[iborg]

Hi Leo


Sounds like you have more than enough background to be able to deal with all this, and then some.


Enjoy


Philip

[LonelySpoon]

Making sure you get to enjoy what you want to do is too easily put aside, Leo!

Don't forget to share some pikkies when you've made progress.

Cheers,

Neville
LSO

[Leo.G]

I'll definitely take photos of my build when I get to it.
I've done a little research and everyone seems to use V slot for every bit of the frame. It really seemed to make little sense when they then screw a linear rail on top for the movement of any axis. V Slot 2020 is far from cheap purchased in one metre lengths.
My son suggested I fire up the TIG welder and re-learn how to use the thing for aluminium and use aluminium box section for the bulk of the frame (I can use steel and can MIG or stick weld it). I can basically buy a 6.5 metre length of aluminium square hollow section for the price of a one metre length of V Slot.
I guess I better buy the 4030 filler rods, the things I purchased locally don't stick to any alloy I have here (mostly 6061) but that's probably a more "I can't see the weld pool with my vision" problem than filler rod problem. Even with an expensive auto helmet and glasses on I struggle to see a weld pool with any welder.
There's always rivnuts.....

[LonelySpoon]

Leo,
I find the v-slot too expensive as well.

Have a look for "Root 3 CNC Mill". It uses square section steel set a 45deg.

This is the way I'll be updating my big CNC mill, and I can't see why it wouldn't work for a laser.

Cheers,

Neville
LSO

[Leo.G]

Thanks again Neville!
Yes, if funds are limitless V-slot would be the go, easy to work with but I can weld steel (I used to be considered an excellent TIG capable welder with aluminium over 20 years ago when I had better sight).
I can get the 25mm square hollow section in alloy cheap enough new in 6.5 metre lengths from memory, I have a cylinder full of pure Argon and a near new AC/DC TIG welder I can't remember how to use.
If I can get my eye in I should be fine and I have plenty of scrap to practice on if the weather fines up again.
Otherwise it's steel box section and the MIG or arc welder. Steel isn't an issue weight wise because it will be on good castors (likely) but won't be something I'd be moving, just sitting in one corner for use.


As mentioned, I have a lathe and mill at my fingertips but the mill needs a stand. I purchased a separate compound table for the unit and lost the lay out I drew to make a stand to suite while I had the table at an engineers to be drilled and tapped. I play with anything but cast iron, I hate the stuff with a passion, whether welding or drilling and tapping it. It was easier to get a friend with all of the equipment and a lot of experience to do it and throw him some dollars for his time.


What really confused me with all of the V-slot material I saw used in various home projects, the people didn't use it with a carriage as intended, they secured slides with a separate bearing roller unit.
It seems like it was all for show for the project list but using linear rails to carry the load instead.

[Leo.G]

This is a BIG rabbit hole I'm finding.
I'm trying to figure out mirror diameters, lens thicknesses/profiles WOW.
If only I'd bothered learning to read when I was a kid, probably too late nearing mid 60s I guess......


To the mention of decent power supplies and Meanwell units, I have this beautiful Meanwell 24 volt 21A power supply I'd purchased from RS online when I grabbed one or two 12 volt units for other peoples equipment, fixing one friends (sort of/was) business security system, wiring up a massive supply for Christmas lighting at another former associates house. I had no need for the 12 volt units at the time but grabbed a bargain 24V unit for later use, then around $150 odd. Now the same 24V power supply on RS components is $470+
I have no idea what happened.


BUT, searching for suitable stepper motors for this project and another of my sons projects we came across Stepperonline on AliExpress.
We liked this particular seller because every stepper has a torque curve graph. Now we've gone to their own site where it's cheaper for me to purchase 3 NEMA 17 steppers with controllers (once I make up my mind) and found they have a HUGE range of not only stepper motors but also a lot of related equipment including the Meanwell power supplies.


Their prices are AMAZING and I'd strongly recommend anyone chasing a particular power supply to check their prices first.


https://www.omc-stepperonline.com/switching-power-supply


Absolutely no affiliation but prices like these I've not seen in Aus anywhere for some time.
Pity they aren't called laseronline, I'd get that power supply too (they don't carry laser power supplies)....

[Leo.G]

I've ordered the laser power supply, mirrors and a laser head/lens, all from AliExpress while they have a sale on (anniversary sale I believe). I saved a considerable sum of money and just hoping everything is right for my intended purposes.
Once it gets here I'll start designing a cabinet. Though my son showed me a video yesterday of a vertical unit and I'm thinking a design like that would definitely have a smaller footprint in my limited space.


https://www.youtube.com/watch?v=136HqrXOMpw

[bojan]

For quite some time I have laser cutter in my plans for.. whenever.
Laser is 2W (violet-blue) unit (so, perhaps adequate for engraving plastic and/or paper)...
I plan to use GRBL code (https://github.com/grbl/grbl) (running on Arduino CNC3 h/w) or Repetier (for Arduino MEGA + RAMPS14).
The mechanics on picture was designed for coordinate drill (that is why Z-axis is there) so it will be universal contraption..

One day.. :shrug:

[Leo.G]

That looks neat!
I'm not sure whether the laser diodes themselves cut plastics or engrave them well, I know they are good on glass.

That's why I went with the CO2 unit, only a 50 watt unit to start because it was affordable. I've purchased a power supply capable of powering a 100 watt laser should I decide to upgrade in the future if I need more power.
My son suggested the same bed for my plasma cutter, CNC controlled but the plasma cutter creates a lot of splatter, I don't think I'd want it where mirrors and other optics are. I'll figure it out later, I don't use it much and am happy to hand cut when I do. I do need a set of guide rollers for the plasma though, my free hand is not what it used to be.


I like the Arduino, I don't play with them but my son has spent many hours with them and has several. I have a new Raspberry Pi 4 here I don't use, hopefully my son will. I get confused, I studied PLC's and am familiar with ladder logic and control but writing libraries escapes my abilities. Though PLC's are far out of my price range just to play, the little PIC's are a huge advancement for home users and cost efficient in comparison.

[LonelySpoon]

>I'm not sure whether the laser diodes themselves cut plastics or engrave them well, I know they are good on glass.<

For what it's worth, my little 7W diode laser only just marks colored Perspex.

100w will cut it though :D

Neville
LSO

[Leo.G]

I could be wrong but I thought I'd read somewhere CO2 lasers were required for acrylic. Then again I read so much stuff that vacates the building the moment I scratch my nose.......
I used to have better than a photographic memory, I don't miss my teeth (well, sometimes), I don't miss my hair (it's only thin on top where I can't see it) but I do really miss my photographic recall.

[bojan]

The worst part is, I relied on it so often.. and because I always could recall images (even text from books), I didn't develop "normal" practices, like writing down notes.. Now I my PM is gone and I still don't make notes :sadeyes:.


BTW, acrylic is not transparent to IR, so CO2 laser can deliver energy into material, to melt or even evaporate it.

[Leo.G]

My initial purpose is to make light guide plates to light up some images I've had printed on canvas, only where I want it lit up so just small recesses in one side.
Yes, memory, I did many years of study at TAFE across a range of fields suitable for mechatronics and went through everything and got distinctions across the board, read it once, in there for life or at least till 55. Maybe it was the double fives that messed me up, lol.

[LonelySpoon]

Didn't some old rocker (Ozzie Osmond?) once say "Of all the things I've lost over the years, I miss my mind the most"?

Neville
LSO

[Leo.G]

I don't miss my mind, just my memory recall.
I still remember all of the stuff I'd rather forget though.......

[Leo.G]

I got some bits and pieces today from AliExpress. It all appears to be of a very high quality. I also got a set of good (I think) mirrors and primary lens (the good type) but have chosen to leave those packages sealed until the build progresses to a point where I need them. Build hasn't started and judging by this rain won't for a while.
Plus I have the 50 watt tube already. The power supply appears to be well built and will handle a 100 watt tube should I eventually decide to upgrade.


Funny, I purchased an extra connector set (white plastic/something twist together 2 piece thing) and 5 metres of the good 5mm high voltage cable. I didn't realise the PSU came with it, it wasn't shown in the listing. Along with glasses suitable to the 10,600 nanometer tube (it sounds so much better than the pathetic 10.6um things, LOL). I've also ordered a good quality current control panel (all purchased when AliExpress recently had a sale and I've saved well over $100 off current prices) still somewhere in Aus posts system, hopefully.........

[LonelySpoon]

the mounts, etc certainly seem on a par with my commercially obtained unit, Leo.

I must admit I'm a bit paranoid about getting a 10kV whack from mine, as the connectors to the tube are simply alligator clips!

Neville
LSO

[Leo.G]

I'm going with something more secure than alligator clips.
In saying that, despite this PSU having two EHT (line output) transformers, the output of one going straight to the input of the other and I'm guessing it would be a NASTY nip but I've been stung before, too many times to count.
Part of my job building and repairing TV's at National and Rank had me looking at the screen directly and reaching around inside to adjust stuff, blind. Back then they'd switch out to live chassis models and if you weren't paying attention... Then the EHT transformers, grabbing the wrong thing there.....
And NEVER touch a picture tube lead until you prod the input and short it to ground.
What's a picture tube? :Haha:

[Leo.G]

Neville is your system running belt drive or ball screws?
I've seen mention ball screws are better for accuracy than belt and the other screw type thingies ah, lead screws.
I've not slept and my brain is mushier than usual.
Any mushier and it will be seeping out of my ears.......

[LonelySpoon]

My laser uses belts, but my CNC router uses leadscrews.

I think my focussing introduces more error than the belts might...

Neville
LSO

[LonelySpoon]

Come to think of it, my focussing is always the problem with my astro-photos too.
:D:P

Neville

[Leo.G]

I have the same issue, I think it's something to do with age, or I've stared at too many pretty ladies (not that that's even remotely possible in my town, there's an obesity endemic).
Size 46 (women's size) lycra gym shorts (that's a slim lady in Lithgow) and a sports bra that could launch two space shuttles at once seem to be classic "I'm going to the shops" wear.
I don't remember any such problem when I was young.


End of rant!


In all seriousness my employment from leaving school for the first 5+ years of my working life did involve my face 2 inches from a CRT TV screen while my hand was blindly making adjustments inside the cabinet (you soon remember where not to touch, especially with live chassis models ). CRT picture tubes emit X-Ray radiation and I'm sure that's had a bearing on my vision

[Leo.G]

Now I want a beam combiner and another laser tube and PSU after my son doing research.

[LonelySpoon]

Welcome to my world, Leo!

Currently printing parts that take 10 hours / piece for the CNC router rebuild.

Having to decide "CNC or astro?" with the spending is a hard choice...

Guess I can't spend it when I'm dead...

Neville
LSO

[Leo.G]

My choice is food and bills or toys I want to build, I've been on disability for a lot of years.

[Leo.G]

I've looked into acrylic sheet sizes. I'm not in a position to drag a trailer down to Sydney to pick up standard 1200 x 2400 sheets but a standard cut size is 4 off 900 x 600 and from memory 2 off 600 x 600 pieces. The 900 x 600 I will cut down in half to 450 x 600 which will fit what I primarily want to do with only minimal scrap.
My primary use will be making light guide boards to light up canvas prints from behind. I'll also be selling various prints once I'm done with the machine and have enough experience.


Therefore I've decided I need to make a machine capable of taking 900 x 600 sheets. I'll also be building a little redundancy into the machine with the capacity to add a second laser tube, power supply and beam combiner to increase capacity (along with necessary electronics).
I have no intentions of cutting/engraving timber, it doesn't interest me though I guess if I have the capacity to do so I never know what I could end up doing.


Now I have to look into linear rails and I'm guessing I need them a little larger than my total sheet capacity. I'm thinking 1 metre for the laser head movement and a 700 odd linear rail either side to give the other rail (on whichever axis is which) smooth, even travel in and out.


Neville what do you use for air assist?


Is it a stand alone compressor built into the machine (small air pump)?


I need to look into air assist and cooling too. I recently gave away a portable air conditioner I could have used to chill the water and knocked back a water chiller which takes the big bottles. I had no need of either then (spare air con unit I was given just after I'd bought one and never used).

[LonelySpoon]

That's why I never throw anything away! (It's also the reason my 150sq. m. shed and its' mezzanine are full...)

I have a smallish pump sending air to the head. It's a bit awkward to get at under the body but looks like a tyre inflator on steroids, or an industrial fish tank aerator maybe.
Fumes as mentioned are removed by a cycloidal extractor to the outside.

For the frame/bed, if I was building your set up, I wouldn't go past this one:

https://youtu.be/24RslguGy58?si=iXhwFQHRCttM8T6N

It is what I'm making to upgrade my cnc router and will take around 1000 x 850 mm.

I've been 3D printing for days to make all the connectors, etc.
If you don't have a printer already, mine cost $360 on Amazon.

If you prefer belts to leadscrews, his version3 has them. I had all the bits already so went with V2.

Neville
LSO

[iborg]

Hi Leo

Unless you know you need chilled water, something like this (https://www.pccasegear.com/products/51768/corsair-hydro-x-series-xr5-120mm-water-cooling-radiator), with a fan and pump may well do the job for you.


Similar units on Fleabay are cheaper.

Simple and not expensive.

Philip

[Leo.G]

Thanks gentlemen!
I don't have 3D printer capabilities and am not a fan of plastics for making stuff and was looking at some nice linear rails for a reasonable cost from an Aussie online place. If I wasn't so lazy and got outside while the sun is out today I could start welding up the stand for the milling machine I bought my son and that gives us the capacity to mill bits and pieces we'll want or need. It's not CNC but that will eventually be in the works. I ran out of argon shield gas, still have straight argon for the TIG I forgot how to weld with but I have a gasless spool here somewhere for the MIG, I can also use the arc welder, I bought 40x40 square hollow section with 4mm wall thickness for the stand. I have to get to the doc's in a couple of hours, no point in starting anything now and by the time I get home it will be too late to start I'm guessing.
Tomorrow.......


Cooling I have a nice rear refrigerator coil and smaller radiator (possibly out a a stripped chest freezer) here. Winter just running straight water through the big unit from the old fridge hanging externally on the wall of the shed would probably be sufficient but I will invest in a chiller of some description or strip the still new chest freezer I bought for an emergency (to freeze water bottles) when my old Kelvinator gave up the ghost until I got the cash for a new fridge. We don't use it for anything.

I also have a lot of Peltier coolers we play with and can mill a block (see comment about stand).

[Leo.G]

Neville you mentioned your machine is running belts. What type of linear rails does it use?
I'm stuck between the round bar type and the flat runner. I know the round bars are better for vertical but I won't need vertical slides.
I'll have to make a decision soon to get started on a frame before winter hits. I don't like welding in my back yard in winter, especially not if I have to use the MIG or TIG with gas (I'm out of gas for the MIG and TIG gas straight Argon isn't suitable), probably go gas-less but I'm not sure how that is in the wind. I should imagine it's fine since shielding gas isn't getting blown away. I haven't used gas-less wire much in the past.
Until I get the rails I can't design the frame.