December 2, 2021

I, Science

The science magazine of Imperial College

Ingenious homemade inventions with neither functional nor practical application - from cheese-controlled cars to machete-shooting slingshots ...

There’s no doubting the creative ingenuity and innovative resourcefulness that goes into Do-It-Yourself science projects. However, while many of the home-built technologies are designed with clear practical applications in mind, there are some innovators who prefer to let their creative sides run wild. Here are six of some of the more adventurous designs, crafted by individuals who refuse to be held back by such boring norms as ‘functionality’ or ‘practicality’.

Machete-shooting slingshot


Jörg Sprave is a slingshot enthusiast like no other, creating some of the deadliest-looking contraptions you never could have dreamed of. His masterpiece: a slingshot that fires machetes. Custom made in the shape of a rifle, it sports a trigger for firing the weapon, and an exceptionally strong rubber band to hold the modified machetes in place. Although this mega-weapon does indeed work – driving the machete up to its hilt in the target – short of a zombie apocalypse there isn’t much practical use for it. Not to mention its unwieldy ammunition makes it both slow to reload and very expensive. Unless you plan on retrieving a lot of machetes out of zombie corpses.


The cheese-controlled car

Conor O’Neill, a particularly resourceful father, was determined to give his children a memorable Christmas present. Starting with an i-Racer – a Bluetooth-equipped toy car that can be controlled by an Android phone – O’Neill toiled through some tricky coding to link up his Raspberr y Pi computer as a controller. Not stopping there, the determined dad incorporated a MaKey MaKey invention kit: a system that allows the user to convert everyday objects into inputs for a computing device. Thus the cheese-controlled car was born: five pieces of cheese acting as buttons, connected to a Raspberry Pi, controlling a car over Bluetooth. And as if cheese wasn’t enough, O’Neill was also able to use grapes and a Barbie doll as controlling mechanisms.


Tesla gun


By using mainly scavenged parts, Robert Flickenger managed to construct his own fully-functional 20,000-volt Tesla coil gun for only £500. He created the body of the gun by melting down aluminium scrap metal and pouring it into a mould of a plastic Nerf toy gun. The current, provided by a lithium ion battery from an electric screwdriver, is repeatedly doubled inside the gun using a transformer from an old television and additional circuitry, while a fan from an old computer server helps to cool the spark gap. He proudly debuted the lightning-blasting gun at his wedding reception.


Levitating bed

Reddit user ‘mememetatata’ built himself an incredible floating bed from a simple wooden frame, hockey pucksized neodymium super magnets and steel cables to hold the bed in place. Neodymium is a rare earth metal and the strongest permanent magnet known; apparently, the hardest part of the build was prying apart two magnets that had become stuck together during shipping. Although this is a fully functioning bed, it is made impractical by its maximum weight of 110 kg (so only enough for one person) and its obvious exclusivity to users devoid of any piercings.


Set Phaser to ‘Stun’


Yet another weapon makes our list. This time a handheld Star Trek phaser gun that shoots a continuous blue laser beam from the barrel, and even imitates the oscillating, futuristic noise when fired. To build it, the inventor picked up a PlayStation 3 laser assembly and wired it into a Star Trek plastic phaser toy. He had to exchange the AA battery holder with a 9-volt holder to deliver maximum charge to the Blu-ray diode. Although the sound comes from the in-built speakers of the original toy, the new beam can blast through the tough membrane of an inflated balloon at the distance of a garage length. Cardassians beware!


Power Pram

Father-to-be Colin Furze turned his attention to baby transportation as soon as he discovered his girlfriend was pregnant. The result was a petrol-powered, twin exhaust baby carriage that reached 53 mph at a local racetrack: the first world record of its kind. Built around a 125 cc motorbike engine, the pram comes with a built in wheeled platform and handlebar controls for the parent, and a steel roll cage cot for the child. But it’s only housed plastic dolls so far: Furze says his new-born son Jake won’t be included in any record-breaking baby rallying just yet.