Picture of Yet Another DIY Diode Laser Engraver

I always loved CNC machines! They are the future since they were first invented! I still believe that CADing and CNCing are miracles. When the first printer arrived to my home (I was about 10) I got really fascinated by the fact that I could print a paper about a hundred times by writing it just once!

Only recently I got comfortable with the parts and knowledge needed to built a CNC. I really needed a kind of plotter for my work. As you know a Commercial Laser Engraver is really pricey and a good one is simply out of reach...

To make a long story short I decided to build my own... The funny part is that when I started designing I didn't know Instructables so I reinvented the wheel in many cases...

So here we go: my Moving Gantry Arduino-Less Laser Engraver...


You can also use this machine to create PCBs. Here is my Instructable about it

Here is an Instructable with a better machine using the same parts: Repurposing my Laser CNC into a multi-mount CNC

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Step 1: The Design

I had NO experience on such machines. I just liked them a lot. The only CNCish machine I had built at the time was a (Arduino-based) coil winder, with auto-traverse winding and (of course) winding counter. No axis, no steppers or servos, no gantry precision issues, no G-Code, no anything! It was a clean start!

The first Design had to be changed in the process (that is utterly bad sometimes) but at least was working at first glance. The "gantry", for example, has changed about 3 times since then (pictures on next steps)...

As you can see in the pictures it is a really budget (to cheapish) project. Axis drivers are bought at 1.50€ for example. But lets be more precise:

Axis drivers (that white pipe - "απλή ντίζα" in greek - no english translation but I got it at a shop selling paint) 1.50€ per meter Needed 2 meters so 3 €

Copper pipe used for plumber jobs (12mm outter diameter) 2.90 € per meter

Needed just one meter and I really have enough for at least another one built!

MDF wood Base-Frame about 10 €

All screws and anything else needed (and shown in the pictures) are things an average hobbyist have lying around. In any other case they can be easily found at paint shops and plumber shops (this metallic tape "τσερκοταινια" in greek- for example -that I have no idea about its english name-).

So the Sum for the Frame is 15.90€. It could be cheaper if I had replaced the wood with foil or something, but being functional was an expectation...

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whamodyne2 months ago

Very sweet! I am also looking at the NDV4542 laser diode in a CNC engraver. Could you tell me what current you are running at? 100ma? 125ma? 200ma? Thanks!

john1a (author)  whamodyne2 months ago

Sure! It is about 125mA. I have run one at 180mA, but it died (LEDed is the laser enthusiast word) after 2 days.

All sellers have a "<200mA" or "<250mA" warning but the real datasheet (embedded here for you) has a different opinion about the subject: 130mA MAX current at Continuous Wave (that's what CW stands for). You can also PWM the diode with higher current. If you don't know what this is you probably don't need it. I always use CW though.

Be careful with the amperage and measure it using a "Laser diode Test Load circuit". Just google it if you don't know about it. It is an "under dollar" circuit to test the exact amperage of your supply at any possible voltage you will need using a Digital Multi-Meter.

Also use a Constant CURRENT (not voltage, because laser diode resistance isn't fixed - goes down with high temperature and ups current) supply. The lm317 IC does the trick for me (see schematic).

I have also uploaded my (variable current - you may want a different diode sometime) driver circuit with the on/off switch that goes straight to the parallel port (I use a TIP121 NPN transistor instead with a 1kΩ resistor at gate).

john1a (author)  john1a2 months ago

I also supply the LM317 circuit with 12V. But 9V is equally good.

halamka3 months ago

Make the laser cut silicon chips. Since the beginning wires had to be welded onto a substance stranger than glass. Using a match etc. fuse aluminum powder onto a siliocon wafer side. Then cut individual diodes.

halamka3 months ago

Does arduino make you an enslaved Microsoft user? Did paul allen think of arduino to stave off BASIC computers that simply bypass Microsoft? I have an Atari 2600 and a card that says BASIC on it. I will try it somtime. The ASCII code for return is 0000 1101. Now think of a flat surface with flow chart symbals. Think of a memory block that can hold BASIC program lines that you have just typed in.

samern4 months ago

OMG, I so miss Greek. I grew up in Athens and just love to hear it....even more so in an Instructable. Your απλή ντίζα (Axis Drivers), that white pipe, in the US and likely the UK is PVC pipe, which is also a plumbing supply and for us would be a Home Depot purchase. Having built a few things like this, you need to make sure there is no 'slop' in your carriage, and what I suggest is at the same store you bought your pipe you buy metal tube and metal rod. Where we are, you can go to Home Depot and buy 3ft (0.9m) of steel tube and 3ft of steel rod that fits exactly in the tube. This way you have no need to tension the x or y carriage and there is no 'give' in either direction. Now your engraver is not taking a load because it is a laser, but if you stiffened the structure, you would get the ability to replace the diode with a rotary tool or spindle and have a CNC machine as well.

Apithano δουλεια!

Poppy Ann samern4 months ago

home depot in UK is B&Q or as close as you can get and not steel the name as well, same racks same set up same items for sale but at much higher prices, i wish Home Depot would open up over here and keep the same prices as they have in USA.

samern Poppy Ann4 months ago

If shipping rates were reasonable I could make a killing sending parts from Home Depot here to all of you in 'Old Blighty' or anywhere else. Alas, this is one of the reasons I never built anything worth anything when I was living in the UK. Just couldn't afford it, let alone house it.

nmylonas4 months ago
Thanx a lot. I'll look into it. Thank you for the response.
Nate_Bro4 months ago

This is great!

I want to invest in a good CNC PCB mill, large CNC Router/Mill, and a 3D printer. but the problem is to build those items I need parts. I have almost all the parts you listed in this build waiting for me at home. I can build a cheap CNC mill (maybe 3D printer) using these parts, and build some crude parts so I can make some decent equipment. I can imagine this thing would be a bit slow, but its better then what I have now. and I could even print my own PCB for the electronics.

Even if I can get 0.06" tolerance on this version I could build something better then using a jig saw!

I must have missed something, how are we hooking up the motors to the computer?

You'll probably have to switch to a more powerful stepper for a CNC mill though, and a pretty good motor to rotate the cutting tool. FR-4 is a nasty material to cut that's pretty harsh on the processing equipment. We use an old guillotine for thick pieces of cardboard to cut PCBs at work, you do have to sharpen it once in a while. For more precise cuts a CO2 laser is always a good option.

john1a (author)  SolidRaven4 months ago

A CO2 laser needs half a room of space to set up. It needs serious ventilation, (water) cooling and more. It also needs optics to transfer the beam from the tube to the material. Expensive things... If you want to build one search for the "2.x laser CNC" open source, open design project. It even has the same LinuxCNC interface with mine.

It is a complete project of hardware (schematics, templates) and software (LinuxCNC plugin for rastering, Pulse per Inch...) and completely free. Many people have made it...

SolidRaven john1a4 months ago

Half a room is overkill, it really depends on what you're going for exactly. I think you're confusing the laser necessary to cut a PCB with the one you need to cut through thick steel sheets. And eitherway, using a Nd:YAG for FR-4 isn't the best of ideas.

john1a (author)  Nate_Bro4 months ago

It isn't slow. Not one bit. It can run with 30mm/sec. That's pretty fast...

You can design a CNC with changing gantry. This way you can build a PCB Mill and 3D printer while only creating 2 gantries and 1 CNC table...

The bigger builds need some Aluminium (and up) frame and *of course* greater motors(I believe 3 Amp motors will do the trick for 1m X 1m build).

I used the LPT port to connect the motors. The sparkfun easydrivers need step/dir signals that LinuxCNC provides automatically in the Parallel Port, given you have configured (via some nice GUI that lets you test everything) which pin goes to which signal.

good job
Sock Puppet4 months ago

Nice one. I hadn't heard of LinuxCNC but I'll be taking a look at it - thanks.

Granzeier4 months ago

Very nice - and well presented (although not too sure about the cat - then again, I am not a "cat person") ;-)

Thank you for this - I think that it is time for me to make one of these laser engraver/cutters.

john1a (author)  Granzeier4 months ago

Happy to hear that! Don't forget to return with an "I made it" answer and pictures...

Also check again the Step 2 as I have added a way to reduce the cost by about 15€ (link to another of my Instructables)

The cat, as you know, is an internet joke, but this particular one helped me with the motor adjusting. If the motor was moving really slow *that I couldn't realize) the cat would just stare at it so I knew that the step signal was slow. If it wasn't moving at all the cat wan;t interested... He is an engineer too!

padbravo john1a4 months ago

I wonder... why the cats are an internet joke?
I am a "cat person", but, did not know about that a cat was some sort of joke..

Not really an Internet joke - more like a YouTube meme. Over time, so many funny cat videos have been posted to YouTube that they make up a fair chunk of its content, and people just started including cats in their videos just for fun.

rafununu padbravo4 months ago

We miss a lot of details and pictures as well, can't you be more precise. About cats, they are the best mix of freedom and intelligence.

john1a (author)  rafununu4 months ago

You are right. It isn't *that* "step-by-step"... The reason is that I didn't know the instructables before I assembled the whole thing. So I haven't many photos and videos to show you with the machine half-assembled, axis tests, stepper driver circuit assembling, and such things...

Plus that if I restarted a similar project I would do everything in a much different way. So I believe some parts of the project aren't that good to actually show and teach how to do them, because they seem wrong to me now...

Either way, you can always ask me in the comments for everything you want and I will answer.

henrikas4 months ago
Where did you buy rack and pinions?
john1a (author)  henrikas4 months ago

Generally you can find racks buy writing "rack and pinion CNC" in ebay search textbox...

There you will find pricey stuff. They should work but they are expensive for a <100euros project... It is better to stick with lead screws (threaded rods) as they are easier to find and cheaper too...

Also search for 3D printer parts. There is an open "Reprap" project (read about reprap and bootstrapping, it is really great discovery) that uses 3D printers to print 3D printer parts. As all those motion mechanisms are needed to 3D printers too, you will be able to find many things this way (they are almost cheap too): motors, lead screws, axis rods, timing belts...

schmitta4 months ago

Yes it was a good instructable. Lots of useful information

Just Cool, but I cannot find where to get the rack and pinion how bout a heads up as to where to find or buy.


mist42nz4 months ago

Where do you get rack and pinion ? It's not something that my local plumbing shop stocks :)

john1a (author)  mist42nz4 months ago

Searched for hours in industrial places. If you can't find that you can absolutely use timing belts (you can find on ebay a bunch)...

baecker034 months ago
love this instructable project. I'm using low price steppers from mach machinery.. low torque isn't necessarily a problem as there are work a rounds such as gear reduction with a worm gear etc. might have to try this, although with a higher power laser.
john1a (author)  baecker034 months ago

Low torque isn't a problem if your gantry doesn't interact with the material you work on. I believe that making a CNC mill with those motors is nearly impossible (a CNC router is absolutely impossible).

But laser just points at the material show it works greatly!

Richi30s04 months ago

Great project! Just had a question, when you used the Arduino to test your motors, did you remove it from the circuit once you figured out the problem? I would like to make a build similar to this one but I do not want to use a pre-assembled board. Thanks.

john1a (author)  Richi30s04 months ago

You don't have to use such board! I didn't either!

Just breakout a Parallel Port Female plug with female headers (or even optoisolators if you are that picky!) and connect everything there...

Greetings from LPF! Special laser safety glasses should be worn during focusing and any time your head is near a focused laser dot. Survival Laser sells them. Don't get the cheap eBay glasses. They don't work. Keep cat babies far away from any laser over 1mW.

I've seen all kinds of things used as bearings. Some of the more igneous include drawer slides. When/if I ever get around to building something like this, that is probably the thing to use.

I really liked to read your instruct able. it is very interesting and partially funny.

I also bought some of those steppers looking for an solution to get the right laser, but in our country You can only deal with 5mW. Your solutions sounds very good and I'm looking forward to see some examples.

john1a (author)  realjohnnybravo4 months ago

forgot to mention that buying a laser DIODE isn't considered as laser. Lasers are banned because some happy hippos pointed with them at the sky. So the "laser" isn't banned as technology (that can be used to CNCs and *ahem* DVD players), but only for products like "high power laser pointers" (like those that sells).

Buying a laser diode (unless you are sneaky and make a pointer with it - absolutely possible, many people do it) is perfectly legal, because it can be used as a spare part/replacement for *lets say* your broken XBox or PS4. you can find Laser diodes on ebay, with free shipping - most of the time.

john1a (author)  realjohnnybravo4 months ago

Those steppers aren't that crappy after all! I have seen a hack where some guy made the bipolar by destroying the red wire coil-to-coil connection from inside the stepper. This way he added much more torque... They also seem to be more precise than the usual 200-step motors

corponramp4 months ago

efcharisto para poli!

great work!! would love to see some samples of it in action.

also would love to see your coil winer project if that is online somewhere.

john1a (author)  corponramp4 months ago

It isn't online. It is my first project and (even if it works flawlessly) it hasn't many things to show. Some TIP120 motor manipulation (already in a popular instructable), a reed switch counter, and a 7-seg display driving... The only reasonable thing about it is the little C++ish library I made for the motors and display. I can upload the library anytime though...

nmylonas4 months ago
Nicely done. I would like to see the end result on a piece of wood though.
I am totally inexperienced in building devices but good with my hands. Do you think I could start looking into it or do I have to have studies on something similar?
john1a (author)  nmylonas4 months ago

Take time with electronics first of all. Just learn some basics. Then start using microcontrollers. Use arduinos at first, then advance to generic AVR IC programming and learn some coding too.

This way you will learn how voltages, signals and such things work. Although you can't see those in the instructable they are the reason that this thing is moving...

I am sure that you could screw the main frame together and get the axis aligned without anyone telling you how. But the inner mechanisms are all electronics...

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