Can you really catch lightning with Mjolnir, the mythical hammer of Thor? If you’re [James Hobson] you can get pretty darn close. He’s a long time writer at Hackaday who’s been building an epic following on his YouTube channel by making the digital effects of blockbuster movies into practical effects. Today he released a video showing how he channeled a jolt of lightning with hammer held high.
The lightning source for this hack is a huge Tesla coil held overhead by a telescoping lift. Humans and high voltage mix poorly, which is why you can’t actually tell this is [James]. He’s wearing a full body suit of grounded chainmail which serves as a Faraday cage, safely directing the current around him to avoid a literally heart-stopping moment. Check out the antics in the video after the break.
Longtime readers will remember [Caleb Kraft’s] take on Mjolnir, a build that placed the Tesla coil in the hammer itself. [James]’ version is undeniably more impressive, with the tradeoff that it’s wholly unportable. While we’re on the topic of mythical hammers, our other most favorite build is the delightful prank build which makes the hammer unliftable except by the recognized owner.
Instructables user [birdycrazy] built a winding rig from a PVC pipe and a bunch of K’Nex. He had recently started a Tesla coil project and needed an efficient way to wind the secondary coil. All of the designs for DIY winding rigs he found on the Internet required parts he didn’t have or simply cost a bunch of money. Then he realized he’d been building with K’nex a lot, and why not build a tool to help him?
He ended up investing only his K’nex elements and a length of 4” PVC pipe for the project. He used a K’nex 12V motor because it plugs in rather than requiring batteries. After the coil had been completely wound he set it to rotate the assembly over a period of several days while the varnish coating dried.
Like so many of the projects we feature, this one started with a cheap eBay module purchase. In this case, it was a little Tesla coil that made decent sized arcs but wasn’t quite good enough. The result was a super-sized solid state Tesla coil with better results and room to grow.
As [GreatScott!] discovered, the little eBay Tesla coil has a pretty neat design. The exciter is a Slayer circuit, a super simple one-transistor design. His reverse engineering revealed that the primary coil is simply a loop trace on the PCB under the secondary coil. Sadly, his attempt to replace the primary and reproduce the Slayer exciter resulted in anemic performance. What’s a hacker to do in that case except build a bigger coil? Much bigger — like “build your own winding jig” bigger. Twelve hundred secondary turns and an appropriately menacing-looking primary later, the results were — still anemic. It turns out the Slayer is just not up to the task. He turned to an inverter circuit that was previously used in a wireless energy transfer circuit, and we finally get to see a little of the Tesla coil magic. But wait! There’s more to come, as future videos will tweak the circuit and optimize the coil for better performance.
It’s no surprise that Tesla coils are a popular project around here, especially the musical kinds, from the tiny to the large. Music doesn’t seem to be on [GreatScott!]’s mind, though, and we’ll be watching with interest to see where he takes this build.
[Electroboom] always has some entertaining videos. He recently tried to run his Tesla coil in a vacuum. The video shows some interesting results, along with his usual bleeped out expletives as he drills into his hand and suffers other indignities in the name of electronics.
Unfortunately, a bit of extra bolt caused the coil to arc internally, eventually leading to the impressive device shuffling off its mortal… um, well, let’s just say its untimely demise. Along the way, though, you get to see some interesting techniques for building a silicone seal for the vacuum chamber, and some neat Tesla coil tricks with a closed off syringe.
What do you get when you combine a Tesla coil, 315 film canisters and a fortune wheel? The answer is of course a film canister Gatling gun. [ScienceBob] has taken the simple film canister cannon hack to a whole new level. The idea is simple, the film canister has a lid that fits tight and allows pressure to build up, so if you fill it with alcohol vapor and ignite it with a spark gap, you get a small explosion that sends the can flying away.
[ScienceBob] uses 21 rows of fifteen canisters each around the wheel. There is a spark gap for each canister, and all the spark gaps in the same row are in series. You need a lot of volts to turn on fifteen spark gaps, and that is why the Tesla coil is part of the game. When the outer end of the wire in one row passes near the Tesla coil, a spark jumps and fires all the spark gaps, igniting the alcohol vapor and fifteen cans are expelled from the wheel. The wheel rotates until all rows are fired.
Last weekend was Sparklecon, the premier meetup in Southern California of dorks dorking around, fire, electricity, welding, and general mischief. Just imagine a party of a hundred or so like-minded individuals at a hackerspace. Now imagine the entire party is the after party. That’s a pretty good idea of what happened.
The event was held at the 23b shop in Fullerton, a true hackerspace tucked away in a small industrial park. The people at 23b are using their location to their advantage: no one in the neighborhood really cares what happens after 5pm on a Friday. This allows for some very loud, very bright, and very dangerous hijinks.
There was something for everyone at Sparklecon, including:
Electric Pickle. Take a stick welder, and put a few hundred amps through a pickle. First, the pickle turns into a sodium light. Then, it turns into a carbon arc light. Best done after dark.
FPV drone racing. Flying around and crashing into trees in an abandoned lot. FPV from a few quads were projected onto the side of a building
Live music! Analog synths and Game Boys!
Tesla coils! This was a 300 amp monster, and completely analog. The spark gap was impressive by itself, but it gets really cool when you steal a fluorescent light from a fixture and stand 20 feet away from the Tesla coil.
Hammer Jenga! Cut some 2x4s up and make a tower of Jenga. Get a hammer, some colorful commentators, a dozen people, and make some competition brackets. Hackaday’s own [Jasmine] was the first champion of the night.
Sparklebot Death Battle! It’s like BattleBots, only things break more often and we don’t have [Bil Dwyer].
Hebocon! Battling robots, but much crappier than the Sparklebot Death Battle. These robots broke more often.
Analog synths provided the tunes
The Sparklebot Death Battle ring
Tesla Coils and Spark Gaps
A Hebocon bot, using a mouse trap as a weapon
A lady tribble, vibrating her way across the Hebocon ring
The basic premise of Hammer Jenga
Art was made out of the spare parts left over from the Hebocon build-off. This robot is named Art
The main event was, of course, Sparklecon’s own version of Battlebots. There were only four competitors the entire night, but the competition was fierce.
Three of the bots were wedge designs, in keeping with the ramp-ification of battling robots. The lone exception to this was [Charlie]’s Slow Bot, a cube design equipped with a spinning steel blade. The blade moves fast, but Slow Bot doesn’t. It’s a purely defensive design, meant to destroy bots trying for an easy kill. The test video of Slow Bot can be seen here:
The first fight of Slow Bot did not live up to the hype, unfortunately. After Slow Bot’s primary weapon got up to speed, the opposing bot moved in for the kill. The bolts on Slow Bot‘s blade sheared, ending the match, and leaving five or six people looking around the 23b shop for M5 bolts, or some larger bolts and a tap.
Is it all hilarously unsafe? Well, there were some plexiglas shields in front of the crowd, and most people viewed the fights on the projector beaming against the wall, anyway.
Is it worth it to go to Sparklecon? If you like dangerous experiments, soldering wires directly onto AA batteries, fire, electricity, electromagnetic fields, broken robots, and hanging out by a fire, yes. It’s a party at a proper hackerspace, making it the best kind of party ever. If history repeats itself, there will also be an afterparty at 23b following the LayerOne conference in May.