Sunday, 13 September 2009

poor's man CNC hot wire cutter - Updated!

This time I built a computer controlled device that will allow you to cut out shapes from styrofoam boards with great precision.

To make it more fun I tried to build the whole thing by re-purposing scrap parts I found here and there, so I used a couple of scanners, a hanger and a hot wire. The scanners I found them on the trash (officially I will deny that I pick stuff from the trash), the hanger I got it from my cleaning service and the hot wire was 3 euros.

This is the way it works, draw a shape using your favourite drawing software or download one from the internet, just make sure the file is a SVG, because that is what my system understands.

I found myself this nice eagle, which is quite a complex shape as you can see:
And this what you get:

Here is the promised video so you can see the system in action...

Here are some pictures showing details of the CNC


mike said...

Hello Raul,

I write for I'd like to do a feature on your hot-wire foam cutter. Can you send me a bit more information on it? Specifically, what is the hardware you are using and how did you build it? I'd love to see any pictures or schematics and hear any description of your experiences in getting everything working. I hope to hear from you!

-Mike Szczys

PaulBo said...

I'd love to see more details on the build as well! I'm very tempted to try this myself; it looks great.

sMiles said...

Nice project. I have a very similar cnc, scanner parts, but I used php to process the svg files. mega16, usb interface, 3 axis. Maybe we can compare our php and pearl code

Amundsen said...

very nice.
Is possible to have your project?
(my mail is:

nomasteryoda said...

Don't be afraid to say you recycled something!! I love to dumpster dive and have gotten many, many good things from dumpsters. Most recent pull was 3 SMC N routers, new in the box sans their power supplies, which were replaced by the Mfg. free of charge.

conundrum said...

very cool :)

i also salvage parts from trash, my most recent "scrapuisition" was a dead epson all in one printer, complete with working internal scanner, steppers and driver board.

Interestingly, the optical reader assembly can be repurposed on some printers (the sort using the cheap PM motor) as a fine positioner using some Polymorph/Shapelock.
Mount the read unit on the scan arm and run the optical tape along the scanner's long axis securing at each end and run the driver off the existing ribbon.

I also repurposed Zip drive ribbons as laser driver lines for my UV etcher..

Amir said...

Great project.

I would love to try it myself.
Would you share the code for it?


SAUL said...

Hello Raul

It is a very interesting project and the result is great looking with what you did, I would love to build, you can
give more information.
My email is
Thank you.


Harsha said...

what is the software you are using?

Raul said...

I wrote a silly python program to drive the CNC

Lozza1950 said...

I have found everything except the board with the 2h bridges and shift register. Can I buy on of the shelf ? Or can you provide part names and circuit .
Laurie australia

Lozza1950 said...

My e - mail is lauriemattila59@ Perhaps you sell me the board ?

Raul said...

Hi Lozza, thanks for your interest!

You dont really need those hbridges I build I just used them because I had them around.

Any arduino shield that helps you move 2 stepper motors will do, this would be the easiest way to build it. You can also use stepper motor drivers that you can buy for $11 from pololu for example, probably that would be easier

Does this help?

Mike said...

This is really a well laid out website. I like how you have presented your information in excellent detail. The best things is you described everything in very easy & clear language.
best business card scanner

The Good Life said...


I was hoping you could help me.

I am looking to cut spray foam off my vaulted ceiling.
The rafters are 16" apart.
They sell tools for this but I cannot afford $300 now, I spent it on foam!

I found a guy that made a hot wire cutter on Youtube with a flashlight and a wire with a coathanger frame.

I dont know alot but it seems to me that the coat hanger would also conduct electricity and heat up.

Any suggestions on what materials I could use that wouldnt heat too much and melt my flashlight?
So far, I have a $3 flashlight that came with 2 D batteries, a plain coat hanger and an old E string from a guitar

Raul said...

Hi TheGoodLife,

The coat hunger has to be isolated from the steel wire otherwise the current will flow through the hanger and not through the steel wire.

I would try googling a bit i'm sure there has to be great tutorials out there on how to build such a thing.

Good Luck!