STORY: Elsewhere on the Infernolab site, you'll see that I've got a thing for LEGO. Ever since I entered 2A in the 1999 LEGO Mindstorms RoboGladiators contest at the E3 trade show, I've been trying to figure out how to make a truly destructive LEGO weapon. While browsing my parts bins recently, I came across an interesting piece from the train sets. It's a connection wire that goes between the train speed controller and the metal rails of the train track. So, it has exposed wires. I figured this could make for a nifty sparking weapon, or at least a cool sparker show-off mechanism. I picked up the part on a whim while making my pilgrimage to the LEGOLand theme park in Billund, Denmark, during the Summer of '95.

Most of LEGO's electric items (battery boxes, wires, electrically conductive plates, motors, switches, etc.) are "idiot proof." That means, no matter how you hook things up, you won't cause any short circuits or blow anything up. Unless you're very crafty. For the trade show competition, we combat robot guys, who were used to running our machines above & beyond recommended specs, figured out (with no modification of any pieces) how to add voltage inputs in series to crank our motors at 18V (instead of the usual 9V), at least until the battery boxes' circuit breakers cut in (another of LEGO's clever fail-safes to prevent a meltdown or blowout). Dan documented his simple voltage adder, so I used his plans for this project, since I'd long forgotten how I came up with the same solution...except this time I kept adding and adding and adding...

SPECS: parts required for a LEGO sparker:

• battery box (each pack's 6 AA batteries adds 9V). I used 12 packs for 108V.
• lots & lots of AA batteries (6 per battery box). I used 72 batteries.
• n-1 voltage adders, where n is the # of battery boxes
  • 6 electric plates per adder (1 must be 2x1, 1 must be 2x4, 1 must be 2x8--sizes of the others are somewhat arbitrary). I used 66 electric plates.
  • 2 electric cables per adder--length does not matter. I used 22 cables.
  • 1 2x4 plastic plate (or perhaps smaller) per adder. I used 11.
• 1 train connection wire
• Miscellaneous plates for organizing & arranging all of these elements. A big baseplate comes in handy.

TECH DETAILS: It all boils down to how many battery boxes, AA batteries, electric plates, and eletric cables you have. And how keen you are on melting your train electric cable...

• 9V: no noticeable spark
• 18V: maybe a little spark, probably my imagination
• 36V: ok sparking action
• 72V: hey, nice spark
• 108V: it smells like burning plastic in here!

SPONSORS: LEGO parts were left over from various previous projects. Worldmachine Technologies helped with inspiration and encouragement.

WARNING: high voltage is dangerous and stuff!