Everyone’s seen the Diet Coke and Mentos “experiment” that ends in a brown eruption. But have you seen the Coke and Propane
experiment insanity that results in a rocket launch? As [Itay] pointed out when he sent us the tip, this doesn’t need to be lit. The simple act of turning the bottle upside down starts a powerful reaction without any ignition.
Of course it’s the how of this that tickles our brains, but let’s finish the setup. This starts with a bottle of Coke which is about 3/4 full. The head space is displaced by spraying propane into the bottle; propane is heavier than air. All that’s left is to turn the bottle upside down and pray it doesn’t smack anyone in the noggin as it takes off.
In trying to find an explanation for this phenomenon we came across a plausible answer on the Chemistry StackExchange. It points to the Mentos phenomenon combined with the temperature differential caused by the very cold propane. The answering user theorizes that tiny ice crystals form and when the bottle is turned upside down the cold propane and micro crystals rise through the warmer soda acting as a much more rapid catalyst than Mentos alone. Of course this is just a theory so please share your own ideas below.
We thought the folks who microwave stuff outside of a microwave enclosure had their fill of danger but this videos is also one of theirs. It should be no surprise that they also tried the experiment with an ignition source. That video is found after the break and should immediately convince you to never try any of this yourself.
Continue reading “Coke-Propane Rocket Blasts Off Without Ignition”
When [JZSlenker] was challenged to find a creative way to destroy a bunch of compact discs that were burned incorrectly, he did not disappoint. He came up with a rather simple but fun contraption that launches the CD’s at high speeds and with a fast rate of fire. He doesn’t share many details about how this machine was built, but the 18 second video makes it pretty obvious how it works.
The CD gun is built mainly from a piece of plywood. This provides a flat base with which to mount the other components. A stack of compact discs is held in place by what appears to be a metal cage that was welded together. An inexpensive angle grinder is used as the propulsion mechanism. The grinding wheel is mounted just in front of the stack of CD’s in a vertical orientation. The wheel must be placed just high enough above the plywood base for a CD to fit in between the wheel and the base. This design is remarkably similar to the Sticker Gun which our own [Brian Benchoff] is building.
Some type of linear actuator is used as the firing mechanism. The actuator is hooked up to a thin piece of metal, cut into an L shape. It almost looks like a reaper tool. When a button is pressed, the actuator fires instantly. This pushes the metal hammer into the CD on the bottom of the stack. The CD is pressed forward into the grinder wheel which then shoots the CD into the air. Based on the below video, it looks like [JZSlenker] is able to fire at a rate of about three CD’s per second with this rig.
This has got to be a super-villain weapon for an upcoming movie, right? Maybe AOL-man?
Continue reading “Fully-Automatic CD Launcher Looks Dangerously Fun”
Prepare to learn. [Grenadier] has put together a collection of information about AC electricity that can safely be called a super-post. In 62 parts he covers a myriad of topics, some of them safe, many of them not so much. You may want to spend time reading through everything that he has to offer, but just in case you don’t, step one is a table of contents. In it you’ll find a listing of major points including transformers of every kind imaginable; from microwave ovens, neon signs, bug zappers, x-rays, and televisions. [Grenadier] covers the type of transformers that these items use, where to find them, and how to set up your own experiments. There’s plenty of pictures and several videos where the high-powered sparks fly. We feel like there’s enough here that we can be satisfied with vicarious AC interactions while safely in front of our monitor and far away from the heart-stopping action.
What do you get when you mix a simple X/Y plotter, a Flyback transformer, and an unhealthy disregard for safety? Possibly the worlds most dangerous jumbo Etch a Sketch! [Kalboon] started off by making an imprecise X/Y movement device, similar to a CNC machine setup, but with less emphasis on precision. This rig is powered by some commonly salvagable materials, including an old scanner, a remote control car, and some hobby servos. We like this approach because most of these materials could be scrounged from a parts bin, surplus sale, or craigslist for little to no actual cost. The flyback transformer comes from an old TV or monitor, though if you have
common sense safety concerns, we would recommend just mounting a dry erase marker and a dry erase board to substitute out the high voltage bits. For people wanting a low cost introduction project to making a CNC or Makerbot style build, this isn’t a bad place to start.
Dabbling in alternative heating technology, [Rob Steves] built a wood stove to dispose of his scrap wood while negating his home’s fire insurance at the same time. As the leftover bits from his wood projects started to stack up he wondered how he would dispose of them. Burning the bits for heat means he’s using every last bit of the lumber. The internal tank from an electric water heater was repurposed as a combustion chamber, with exhaust gases escaping through some high-temperature flexible tubing. The glass panes were removed from one of the fireplace doors to give the off-gases a place to go. The result is a rocket stove that burns very hot and does a great job of warming his house.
It’s not the safest way to heat a home, and there may be coding issues with your municipality. But this might go well in a remote location, like that cabin where you have to generate your own electricity.
Here’s one that brings back that giddy feeling we got when the original episodes of thebroken were posted all those years ago. The lunatics over at Waterloo Labs have altered a beat-up Oldsmobile for remote control via laptop, iPhone, and…. wait for it… Power Wheels.
Brake and gas pedals are actuated using a wrench connected to a motor bolted to the floorboards of the car. The steering wheel has been replaced with a gear and connected to a motor using a motorcycle chain. Much like the van we saw last month, an iPhone app has been written to wirelessly control the car of doom. This leads to some car surfing and ghost riding the whip in the video after the break.
To our delight, they’ve also implement the most unorthodox automotive interface yet, Power Wheels. A chain has been added to measure the orientation of the toy steering wheel, and an optical encoder is used to measure the speed of the tiny electric vehicle. It looks like it doesn’t do the best job of translating to a full size vehicle, but it maxes out their style points.
Continue reading “Remotely Control Your Crappy Car (dangerously)”