Video: CNC machine plays "Still Alive"

This man has configured his CNC router to play "Still Alive", from Portal. Hacksay says he "didn't just tell the motors to spin at the correct speeds directly though. he computer the 3d vectors necessary to produce the notes." I have no idea what that means, since the machine doesn't appear to be carving anything out, but just spinning its motors. Still, impressive. Who knew CNC machines had polyphony?

[#1 posted by rak0ribz, April 3, 2009 11:35 AM]

Lots of stepper motor/drive circuitry combinations produce noise when they're engaged; I think the guy "just" mapped MIDI to distance/rate vectors that ran his 3 axis motors at the correct speed and duration for the desired note. Hackaday doesn't mention this anywhere, but it would be interesting to see whether he did this programmatically or manually.

[#2 posted by Shannon, April 3, 2009 11:42 AM]

The C64 1541 floppy drive could be manipulated into singing as well --
http://www.youtube.com/watch?v=5gnMgmlKi_o

[#3 posted by Shannon, April 3, 2009 11:43 AM]

Scanners too--
http://www.youtube.com/watch?v=jcN9t-x5CDQ

[#4 posted by Anonymous, April 3, 2009 11:43 AM]

now that is fricken awesome!

[#5 posted by Zan, April 3, 2009 11:44 AM]

What you are actually hearing are the stepper motors. While more expensive CNC machines use large servomotors, cheaper CNC machines use stepper motors. Stepper motors only run at one speed, but slower rates are achieved by pulsing them . The pulsing is usually done in the 10Mhz-1.5Khz range, which corresponds quite nicely with the musical range.

In normal use, such a CNC machine makes random R2D2ish noises. By specifying a vector and feed rate, he can make the stepper motors "hum" at any given frequency. The polyphony comes from the X, Y, and Z axis stepper motors.

[#6 posted by Anonymous, April 3, 2009 11:56 AM]

I'm guessing the polyphony is achieved by using each axis to produce a tone

as for steppers running at one speed. I'm not sure where you heard that, it's not true. It would make for a pretty rubbish cnc machine that was unable to produce curves.
Steppers will run as fast as you step the pattern until you reach their slew rate

anyway this is awesome :p

[#7 posted by Agies, April 3, 2009 12:43 PM]

If you dig a little deeper than the Hack A Day page you'll find the blog entry where the guy explains just exactly how he did it. It's here.

[#8 posted by JoeKickass, April 3, 2009 12:50 PM]

When I saw C+C Music Factory I expected to hear "EVERYBODY DANCE NOW!"

...this was better.

[#9 posted by richardnixon, April 3, 2009 1:09 PM]

Here is another musical machine. A Renault Formula 1 motor playing "God Save the Queen" http://www.youtube.com/watch?v=7XR7OpM2Ufk

[#10 posted by Dillenger69, April 3, 2009 1:48 PM]

Wow, this is actually musical, unlike the tesla coil "music" that's been posted previously.

Most cool.

[#11 posted by Dean, April 3, 2009 3:05 PM]

What it means is that, although the CNC mill isn't cutting anything now, the 3D software has a representation of a shape that it's cutting out when it plays the music. In the write up for this project, the author suggests that a hint to his next project is that he can move the notes to different motors and still maintain the correct tone and melody. This implies that it is possible for him to make a shape that represents the playing of the song as played by the CNC mill.

[#12 posted by hypatia, April 3, 2009 4:03 PM]

One of the HackLabTO members did a similar thing with our CNC laser cutter:

http://hacklab.to/archives/another-musical-variation/

[#13 posted by PaulR, April 4, 2009 6:00 AM]

Wow!! The utter coolness of this just moved me to tears.

All we need to complete this is a video with a representation of the vectors being carved out in space.

[#14 posted by bex, April 4, 2009 1:13 PM]

sorry but i am going to call fake, seeing as it was posted on April 1