Introduction: Homebrew Laser Cutter Made by Zach Radding

Picture of Homebrew Laser Cutter Made by Zach Radding

Zach Radding and his daughter Taylor with some robots he built using his own CNC laser cutting machines.
Check out to see more of his projects and info on the classes he teaches.

He's built two laser cutters so far.
Click on the little numbered pictures above to learn more about them.

Note: These are not fully detailed plans.
Included are part numbers of all the major components. If you have already built a CNC machine of some sort,
this information would help you adapt it for doing laser cutting. You should build a CNC router table before attempting a laser cutter. The book "CNC Robotics" from Tab books has good plans. used to send you plans for two cnc machines with a subscription.
Zach recommends for homebrew cnc info. He likes Dancam cnc software.

Step 1: SAFETY

Picture of SAFETY

First some warnings.

The laser beam is invisible. It can blind you and your loved ones in an instant.

Here are the safety glasses Synrad supplies to work with this laser tube.

Read all the manuals that come with your laser tube and do exactly as they say.

The laser can start fires and generate poisonous gases if it shines on the wrong materials.

Step 2: Zach's First Lasercutter

Picture of Zach's First Lasercutter

This first version uses a Roland digital pen plotter to move the cutting lens, and incorporates a number of lasercut mechanical parts.

Zach used the following components. Prices have changed (fallen) since '94 when he bought his, and some
of these things are no longer manufactured. Similar components are available, or you can look for
these on the used market.

Here are the components he used:
CO2 laser tube: Synrad G48-2-285 25 watt laser cost approx $2000
Power supply: Power One Model SPM3E2K 28 volt 27 amp switching power supply. cost approx $300
Mirrors: Four high quality front surface mirrors ~$20 each.
Focusing lens: must be made specifically for the laser wavelength. It must be optically clear to this
color light or it will etch and melt. Zach's lens came as a unit with a 45 degree frontsurface mirror
from Synrad for ~$600

Step 3: The Second Lasercutter

Picture of The Second Lasercutter

Zach and Taylor show us the second version of the lasercutter.
Version one worked fine, but some movers used it as a box to ship a rabid coyote they thought was a pet of his.
The poor animal totally trashed the machine before it got out and bit Dick Cheney in the woods near D.C.
By then Zach had acquired a heavy x-y stage and thought he'd try a different design.
This version moves the workpiece rather than the laser beam. The major advantage of this scheme
are very simple optics. The optics consist of a single mirror that points the laser beam down through the focusing lens.

If Zach builds another machine he says he'll make it more like the first one. Let's look into the guts of this one first.

Step 4: Power Supply

Picture of Power Supply

Power One Model SPM3E2K 28 volt 27 amp switching power supply. cost approx $300

This is a regular switching power supply, nothing special except for capacity and good regulation. The laser tube calls for 30 volts plus or minus 2 volts and thirty amps worth of it. Any supply that will do that is fine.

Step 5: The Laser Tube

Picture of The Laser Tube

CO2 laser tube seen from above.
It's a Synrad G48-2-285 25 watt laser cost approx $2000
Fans in the blue enclosure (absent in this photo) blow air into the holes in this lucite enclosure around the laser. This cools the laser and keeps smoke and other dirt from getting on the front of the laser. This is a good way to keep the laser from burning a hole in itself.
This unit has a number of nice features. It takes a relatively low thirty volt supply. It steps it up to a bazillion volts internally. That's how many volts it takes to make the laser un-lazy. The unit also has a convenient DB9 connector
with a TTL level (five volt) input signal line to turn the laser beam on and off. You can connect a PWM (pulse width modulated) signal in here to turn the laser power down to any level you want. Zach's PWM is at a frequency of 20khz.

Step 6: Motion Controller

Picture of Motion Controller

Zach says: "The newer laser uses an old Galil-600 motion control card. It came with the XY table. I found
a utility (from Galil) that converts HPGL files to a format that its motor controller can
recognize. I wrote a VB app that allows me to preview the cut and send the motion control file
to the Galil card. I'd be happy to share that, but I don't really think it would help anyone."

Step 7: PWM Generator

Picture of PWM Generator

This tiny PIC16f675 microprocessor board runs the the control panel as well as pulse width modulating the beam (PWM varies the apparent laser power thus changing the depth of cut).
This processor looks at the step and direction signals going to the stepper motor controllers.
From this it deduces how fast the workpiece is moving and adjusts the laser power to match. Faster motion,
more power. Circles and other curves cause the machine to move slowly as it approximates the circle from a series of tiny line segments. Then the laser power needs to be turned down to match the slow speed. This is more important when etching images onto something than when cutting things out.

Step 8: Mirror and Lens

Picture of Mirror and Lens

That's it, the whole optical system.

In this photo Zach's fingers are twisting a lead screw that raises and lowers the focusing lens. This is necessary to deal with materials of different thickness. This brings the hottest part of the beam to bear on the surface of the workpiece. Commercial machines typically raise and lower the platform supporting the workpiece instead.

The black triangular dingus contains a front-surface mirror angled at 45 degrees. The thumbscrews push the mirror around to aim the laser beam in the right direction, which is straight down through the focusing lens.

The focusing lens is a single piece of glass housed in the aluminum block attached to the leadscrew mechanism by two 4-40 capscrews. The lens housing came as a unit with a 45degree mirror attached for ~$600. For this machine the mirror was in the wrong place so Zach cut it off.

Below that are some nylon wireties. They ordinarily hold a hose that sucks smoky air away from the lens.
This is important. Without air flow smoke prevents good cutting. Also it gets on the optics and they burn up which is a tragedy except to those people who sell expensive lenses.

Step 9: Airflow and Smoke Eater

Picture of Airflow and Smoke Eater

The hose that sucked smoke away from the lens used to go to a blower that blew it out of the building through a vent. The fumes from cutting plexiglass were so malodorous that the stink drifting back in from outside was unpleasant. So Zach bought this unit. It blows the rank fumes through a charcoal filter which soaks up all the nastiness. It's a RSU12-CCHR "Space Saver" model made by Electrocorp. He says it gives him better air quality than an exhaust fan.

I asked Zach about the possibility of a laser cutter that held the workpiece vertically to save floorspace, whether he thought convection would cause fires. He said no, every laser cutter has to have lots of airflow past the cut, so that problem wouldn't be any different.
In his opinion, the big problem with a vertical workpiece is that cut parts would fall out, shift around, slump, and possibly fall into the cut and glue themselves back together.

Step 10: Pen Plotter Based Laser Cutter

Picture of Pen Plotter Based Laser Cutter

Back to Version One. Zach ordered a new digital penplotter from Roland for about $800. It understood HPGL and its own plotter driver protocol. To cut a part, Zach drew the lines and hit the "plot" button in his cad program.
The plotter went to work, not knowing that Zach had attached his laser and mirrors as shown in this diagram. This is the most common arrangement in commercial laser cutters. Zach didn't have any problem with the mirrors and would
use this arrangement again if he makes another laser cutter.
The plotter had a pen change function for different line styles. Zach added buttons at the pen change stations to tell his laser controller what sort of cut was expected. The controller then sent a PWM signal to the laser to control the brightness of the laser. The pen-up and pen-down signal from the plotter was used to turn the laser on and off.

This diagram depicts the machine as seen from above. Mirror 4 points the beam straight down through the focusing lens onto the workpiece. Mirrors 1 and 2 are fixed. Mirror 3 is attached to the (blue) x-axis gantry and moves side-to-side with it. Mirror 4 and the focusing lens slide to-and-fro on the gantry.

Step 11: Roland Plotter X-y Mechanism Top View

Picture of Roland Plotter X-y Mechanism Top View

This is the mechanical portion of Zach's first lasercutter. The x-axis stepper motor turns a long shaft with two pulleys. Two timing belts move the gantry back and forth.

Step 12: Roland Plotter X-y Mechanism Bottom View

Picture of Roland Plotter X-y Mechanism Bottom View

A smaller steper motor on the gantry moves the pen carriage to-and-fro on the gantry. Zach replaced the pen holder with a bracket for mirror# 4 and the focusing lens. Over time Zach replaced frame elements with aluminum extrusions and various brackets with lasercut lucite parts.

Step 13: X Axis Driveshaft Detail

Picture of X Axis Driveshaft Detail

The stepper motor is attached to a driveshaft with a flex coupling. There is a timing pulley at each end of the driveshaft. The two belts are attached to the two ends of the gantry. Pulling on both ends of the gantry prevents it from racking and means it doesn't have to be nearly as stiff or well-supported.

Step 14: Gantry Underside

Picture of Gantry Underside

The gantry seen from below. The carriage has three wheels that ride on the gantry rail. The carriage is attached to a timing belt driven by the stepper motor seen to the left.

Step 15: Gantry Side

Picture of Gantry Side

Another view of the gantry. Notice the lasercut lucite bracket on the end.

Step 16: Final Bracket

Picture of Final Bracket

This lasercut lucite backet replaced the original pen holder. It supported mirror #4
and the focusing lens.


AnujB1 (author)2014-12-06

how to convert my cnc router to laser cutting

AnujB1 made it! (author)2014-12-06

hi all i have gerber cnc router cutting machine i wont it to convert as a laser and router 2in 1 in my machine

can u tel me how to convert and wht kind of part sued i change r put in my machine

JorgeV (author)2014-11-14

Hi Zach

I am trying to build another Laser Cutter with a Roland GRX 400. I've read that you used the pen selector of the plotter to tell the laser controller
what sort of cut was expected. Please could you send me a photo of the system ant explain me how did you get it.

Thank you very much. (Sorry for my English)

nivinp (author)2014-05-26

I am a newbie into this product. I am looking for a cutting tool. Wanted to know if it can be done through laser. For example, I need to cut a branch of a tree (lets say 3mm to 10mm) thickness. If so, can I use the laser cutter and which laser cutter would be best according to your opinion.

noelsgordon (author)2014-05-02

Very impressed Zach. Apologies if you've answered my question elsewhere. I need to cut 3mm opaque ABS sheet quite rapidly - maybe 4000mm/minute. What power laser would you suggest please ? Is there a viable alternative to CO2 laser for this. I've seen 30W blue & other diode lasers that claim to be focusable on Alibaba and elsewhere. What could these cut please ? I know nothing - less than Colonel Klink - about the cutting capacity of lasers. ps Absolutely gorgeous daughter. Enjoy her, our children are only 'on loan'.

Machine (author)2013-03-15

Thanks for those warnings. A lot of people (me included) don't really have experience with lasers and don't understand the full power they have.

smustafa (author)2011-03-23

the cutest lil baby on earth:)god bless her

askjerry (author)2010-02-25

I was reading your section on the blower... from experience I have learned to put the blower OUTSIDE in a weatherproof container. This way the entire line rom the laser to outside is negative pressure. If you have the blower inside... you may filter some of the smell... but the chemicals in the air can still reach levels to cause you harm in the long run.

I use something like this:$Ntt=deck%20storage$y=0$x=0

If the link doesn't work search for "Deck Storage" or "Deck Box"

I made a lexan plate for my window and have the blower vent at roof level. The air I intake is clean and odor free.

hintss (author)askjerry2010-12-02

aren't you supposed to have the line from the blower lead outside?

TheMadScientist (author)2008-06-29

not very well known, but you can get incredible mirrors by cutting them from harddrive platters. if you don't have a glass cutter, you could also use some of the aluminum ones. both are polished so that not a spec of dust is on them originally, i'd spray coat them as soon as you open the harddrive, or fingerprints will settle on them, but they're as perfect as you can get.

What would you use for a spray coat?

 good question... 

hintss (author)ThingEngineer2010-12-02

hard drives are shiny. also united nuclear sells tiny circular mirrors, less than on inch in diameter, and they're made for infrared lasers. they're in their death ray parts category...

njsoffice (author)2010-09-20

Any chance of getting a look at the head mechanism, like a $250, 150watt 1200mm long laser tube is probably mounted horizontally, secured to the gantry right?. mirrored to/through the head to the work piece. Otherwise, I guess I`ll have to raise the ceiling...ha,ha, vertical mounting (might get wonky when speed picks up), OR... has anyone got any ideas?

Cheers :)

hintss (author)njsoffice2010-12-02

on epilog/universal lasers, its mounted inside/behind the machine, then a mirror or 2 reflect it toward the front of the machine, along the left side, where it hits a mirror mounted to the gantry, making it go toward the right of the machine. then a mirror on the head reflects it downward, through a lens, onto the material

yatishkumar.n (author)2010-01-05

Hi, I'm interested in cutting metal sheets with the help of lase beam, I would like to know how does the CNC system (or) any servo system comes to know whether the metal sheet is cut  or not so that it can proceed for further cutting

 it does not "know". you input settings for power of the laser and speed of the movement, and it cuts however much it cuts. there are suggestions about settings for certain materials probably floating around on the internet, but much of it probably just comes from experience with the tool

Thanks for the info.

fade400 (author)2008-12-19

This question doesn't have anything to do with your project, but rather your experience with lasers.

Right now it's like a blizzard outside. annndd I was just imagining up a possible way to drive on snow covered roads by building a rig to melt the snow under the front of my car with a laser. what are your thoughts on this idea ? I saw some patents with similar ideas (not on a car) but havn't heard of any commercial products. Can lasers be powerful enough to rapidly melt or even vaporize snow ?

Thanks =)

danlab (author)fade4002010-03-27 just put two on the front of your car and you'll be riding in style (or arrested I don't know which)

blacktails (author)fade4002009-09-04

I DO belive that they can be powerful enough, and it sounds like a legit plan, but maybe you should clear it with the government first to see if its ok with them. it might be pretty damn hard to make a laser that strong though......

Rossiroller (author)blacktails2010-02-25

 haha i bet the government probably has that already, only they use it to kill people....

psymansays (author)fade4002009-08-09

To melt all of the snow in front of you at the speed of a car would take far more power than moving the car itself. You would need some kind of diesel generator as well as your car's engine to produce the wattage to feed something like that. Next, the snow crystals would diffuse high-energy laser light, permanently blinding everyone around for hundreds of feet in all directions.

led555 (author)2006-05-03

so this instructable is still in the works? I'm eager to see the source code for the PIC16C74. Will you publish that also? Are those lasers readily available? For how much can I buy one? -peace

led555 (author)led5552006-05-03

I found the price of the laser you're using... $2,000. Did you actually buy it, or was it a scrapped part? Can't you buy a simple laser cutter for $2,000? Just curious.

n6nz (author)led5552006-05-04

$2K? Ummm, not so far as I can tell. I did some web-searching on the subject a while back. For <$10K you seem to be able to get a 25W 8x10 inch, Windoze-only unit. Now, that isn't bad if you are willing to work within the power, size, and software limitations. These are targetted at engraving shops for trohpies and gifts and what-not. The sweet spot in terms of functionality of interest to a hacker seems to be sort of $15K-$20K, which should get you 18x24 inches and 100W in something you can drive with G-codes. 100W will cut a lot of interesting materials, but not shiney metals.

n6nz (author)n6nz2006-05-04

Well, that sucks. Most of my post got whacked off. Does the software not like "less-than" symbols? Better file a defect report. Back to my comment: For under $10K you can get a 25W or so 8x10 inch Windoze-only unit. These are targetted at engraving shops. Of more interest to hackers, in the $15K-$20K range you can get 18x24 inches and 100W in something you can drive with G-codes. This will cut a lot of interesting materials very nicely, but not shiney metals.

askjerry (author)n6nz2010-02-25

It probably thought the brackets were HTML code and removed them.

rivetgeek (author)n6nz2008-11-19

100W CO2 laser will easily cut sheet metal with a polarized filter

askjerry (author)led5552008-12-14

I have a 12x24 inch 35W unit... it cost me $16,400 so I can beleive that a 25W tube would be $2,000 with ease. I'll say this... if you are considering any laser engraver/cutter... don't settle for less than a 35W tube. If I were to do it over... I would have bought a 50W unit. The 35W isn't really enough to do metamark... and sometimes when I'm doing 1/4 inch plastic I need to either run at 1% speed, or make two passes. (I cut some parts that took 1.5 hours... it would have been about 1/2 hour with a 50W, likely 20 minutes with a 75W.) Great project though... at some time I want to build an X/Y table in the 4x4 foot range... and actually have the laser head on the gantry so the distance from the laser to the part remains constant. In my current Epilog unit, when the head is in the lower right corner the beam length is 3 feet, in the upper left corner it is 6 inches... so sometimes I have to adjust cut speed so the lower right corner cuts all the way. With a constant distance... you don't have those issues. Jerry

TimAnderson (author)askjerry2008-12-14

How heavy do you think the laser head would be - the way the head moves around a 50watt gantry might end up looking like a waterjet cutter. Maybe moving the laser with the "gantry axis" would be good. ( I don't know what to call it. on some machines it's the X, on some it's the Y. The motion axis that carries the other one)

askjerry (author)TimAnderson2008-12-14

I'm not sure. My thought was to mount the head and transmit the power via a fiber optic cable... moving the actual head would be option #2. It would likely be much slower... but considering that the laser is faster than a cutting head (mostly) it would be about the same as having a big plasma or drill head. Jerry

Rossiroller (author)askjerry2010-02-25

 ...... couldnt you just have the laser static and move the work piece around underneath it?

askjerry (author)Rossiroller2010-02-25

You could, it depends on what kind of speed limitations you are willing to deal with. On my Epilog unit in raster mode, it swings the head back and forth about 100 times a second to create raster art. Doing vector art it ouwld only need to move at up to about 20 IPM or so. Routing the laser energy via fiber or mirrors allows you to move a 4 oz head ves a 15 lb head.

~ Jerry

thepelton (author)TimAnderson2009-06-01

I have an Epilog laser. The laser itself is static, but mirrors direct the beam where you want it.

zachschi (author)2010-02-08

Where do you purchase one of these units? Directly from Synrad?

linuox (author)2007-12-19

great job, this is awesome, but if only i had the money and time to find all these parts!

winterfresh (author)linuox2009-05-28

Me too..... *Sigh*

matroska (author)2009-05-28

I'm planning to build a laser etcher out of a printer (rest assure, if it works out properly an instructable is to be expected).

However, I don't have a clue at all on making the laser part. What laser should I use? How can I supply it?

I've looked quickly and stumbled on this: ebay link

Is that the kind of thing I want?
Remember, I am starting from scratch. What I already have is the X and Y axis, all I need is the laser part of the laser etcher machine.

Thanks! I badly need help about this :)

TimAnderson (author)2008-12-14

Has anyone seen good plans for a homebrew CO2 laser? Made one? Had a job making them?

A website called Information Unlimited has plans to build CO 2 burning lasers.

shifty (author)TimAnderson2009-02-20

this site has all kinds of information, including kits and pictures and reviews of kits, design tables, safety advice, where to get supplies, everything. Except perhaps detailed info on the gas regulation.

and this site has a wonderful pdf on making a 35W CO2 laser. the pick of my late-night web surf:

Newblit (author)2008-11-05

This is great but change the name to people who have money home brew or something along those lines lol. I mean you spent a lot of money on this lol. But great post otherwise.

sadunpererarules (author)2008-04-25

i think ill make one tommorow.

rockthemfilas (author)2008-03-06

ummm MY head HURTS

The_pyrogeek (author)2008-02-10

Nice project! But kinda expensive...

Wannabmaker (author)2008-02-08

I get a warm fuzzy happy feeling inside everytime i see instructables for laser cutters that show me parts that i want to use but was affraid they would be in-adiquate. I really really want to build one of these within the next 2 primary target material is going to be Balsa Wood.some nice fast cuts would be good,im thinking somewhere in the range of a 40Watt laser should be good. I have a MM2001 interface for my CNC Foam cutter,it would be so cool if i could hook that up to some different software and use it on a laser cutter :P thanks Zach,you really made my day

BlueFusion (author)2008-01-31

is it just me or are most of the pictures missing?

neotom666 (author)2008-01-26

Johnny 5 and you make a pretty cute kid!

ivanirons (author)2007-12-16

Great Instructable Zach! The parts I loved were in the X,Y,Z portion. I like you take on machines/gantries for a project like this. I so far am a bit scared of lasers. I do like plasma though.
I also instruct others. I have made a number of tutorials on various CNC Projects. I like to walk people through each step during the CNC Process. I get great feedback from people just entering our cool CNC Hobby.

Here are the videos:

Then click on the link on the left.

Thanks for your contribution,
Ivan Irons

About This Instructable




Bio: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of, manufacturers of "3D Printer" output ... More »
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