I built this in one afternoon at my parent’s place in Wisconsin–in a town that lacks good hardware stores. While building it, I was thinking of making something that was simple but awesome for a Women in Engineering outreach event we do at my day job. The total cost was about $16, but that included a full roll of electrical tape, a whole
box of toothpicks, and a large bag of thick rubber bands.
It generates nice thick sparks of about two inches that are visible in a lit room, beautiful thin fractal ones of about 6 to 8 inches in the dark, and it’s actually strong enough to generate a visible, bright blue corona around your finger tips if you turn the lights off.
He brought it to the Hack Factory last Wednesday, and we shut off the lights to check out the sparks and corona discharges. While the sparks weren’t crazy huge, we employed ancient electrostatic volt meter and were able to measure 6kV — not bad for a few bucks in parts.
As a derivative project, Hack Factory member Jon Barclay designed a 3D-printable enclosure as a substitute for the PVC — a printable VDG generator! He has entered the project into the Rubber Band Contest currently being held on Thingiverse.
(OK, so it’s a bit inaccurate to say the VDG costs only $5, but it’s really, really cheap.)