Riding rockets and jets around the frozen wastes of Sweden

An attentive reader tipped us off to the guys at Mobacken Racing (translation), a group of Swedes dedicated to the art and craft of putting jet and rocket engines on go karts and snowmobiles.

One of the simpler builds is a pulse jet sled. Pulse jets are extremely simple devices – just a few stainless steel tubes … Read the rest

Piano Box is a digital synthesizer made of paper

We love the look of this papercraft piano which [Catarina] built along with some friends at NYC Resistor, a hackerspace in the big apple. It starts off as a cubic black box with a white top. But just lift that top as [Catarina] does in the video after the break and three of the sides fall flat to reveal a … Read the rest

Polish your understanding of capacitors by building this meter

Building a capacitance meter is a great exercise. If you’re feeling quite safe in your digital-circuit-only life, this will push just far enough out of the comfort zone for you to see there’s nothing to fear in adding analog circuits to your designs. Here, [Raj] compares a voltage divider and RC timer to calculate the value of a capacitor. … Read the rest

Resurrecting a cellphone with blown USB circuitry

[Script] is pretty lucky. One of the engineers who designed his cellphone included over-voltage protection in the circuit. Of course you probably wouldn’t know about this if there wasn’t a service schematic available. But a bit of searching around let him resurrect the fried USB segment of his Nokia N900.

Now [Script] has been experimenting with portable solar power … Read the rest

Collecting Radon data in the name of science and safety

radon-data-collector

When [Chris Nafis] built an addition onto his historical home he found that a Radon problem, previously mitigated with plenty of concrete, seemed to rear its ugly head yet again. He eventually resigned himself to installing a Radon fan and detector – the latter of which offered no way to store measurement data. He wanted to get a better feel Read the rest

Building an artificial heart with ferrofluids

Here’s something we thought we’d never see on Hackaday. [Chris Suprock] is developing an artificial heart he calls Steel Heart. It’s an artificial heart powered by electromagnets and ferrofluids.

The idea behind [Chris]‘ artificial heart is ingenious in its simplicity. An elastic membrane is stretched across a frame and a magnetic liquid (or ferrofluid, if you prefer) is poured … Read the rest

[Aaron] shows us what life would be like if [Bob Vila] started hacking headphones

construction-headphones

[Aaron Horeth] had a pair of headphones that had seen better days, and before he tossed them out, he realized that he could use them to build a set of custom cans. He had always wanted a pair of headphones with a detachable cord to prevent damage when tripped over, and thought that his old set would be the perfect … Read the rest