[colah2]

I bought the DC motor for the second one I'm making at active surplus for $1.95. The cloth was under hacklabs sink in a package of 10 that cost ~ $5, and I didn't use a full cloth. The tape was sitting around, but probably cost about $2 (the one I used this time was taken out of an old vacuum cleaner, ironically enough). The power supply was a fancy one and would cost >$100 but I could have bought a cheap converter for $5. And I used a dollar or two of plastic.

So, even if I'd had to buy everything from scratch, it only would have cost me ~ $15. Since that wasn't the case, it only cost me my time and some negligible expenses. Meanwhile, the cheapest portable vacuum cleaner I could find at the stores I went to was $39.99 + tax...

Also, we're not that far from printing motors. Fab@home has printed metal by dissolving it into a thick paste and others have printed grooves and run solder through them. Once I can print metal coils, I can print a motor... (Some motors don't need an internal magnet -- see http://en.wikipedia.org/wiki/Induction_motor)