How A Hacker Jump Starts A Car

Here’s the Scenario: you need to get somewhere in a hurry. The problem is that your car has a dead battery and won’t turn over. The Obvious solution would be to call a friend for a jump. But is the friendless hacker out of luck in such a situation? Not if you can whip up a quick parts bin jump starter.

Clearly, [Kedar Nimbalkar]’s solution would be practical only under somewhat bizarre circumstances, so we’ll concentrate on what we can learn from it. A spare PC power supply provides the electrons – [Kedar]’s 250W supply pushes 15A at 12 volts, which is a pretty respectable amount of current. The voltage is a little anemic, though, so he pops it up to 14.2 volts with a 150W boost converter cooled with a PC fan. A dual panel meter reads out the voltage and current, but a VOM could substitute in a pinch. About the only thing you might not have on hand is a pair of  honking 10A diodes to keep current from creeping back into the boost converter. [Kedar] claims he got enough of a charge back in the battery in five minutes to start his car.

As jump-starting goes, this hack is a bit of a stretch. It’s not the first time we’ve seen a MacGyver’d jump starter, though, and you never know when the principles and hardware behind these hacks will come in handy.

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Super Slick, Super Portable Styrofoam Slicer

[The King of Random] always seems to have something fun going on in his shop, and his builds tend to be impressively complete. No exception to that rule is his recent hot-wire foam cutter that looks like a ton of fun both to build and to use.

Starting with a simple PVC tubing frame to form the bow of the cutter, the rig ends up looking a little like a scroll saw when [Random] is done with it. A generous work surface sits atop a wood frame, which houses the electrics. A light dimmer and step-down transformer control the cutting wire’s temperature, and the bow even pivots to allow the wire to make miter cuts. A nice final touch is that the frame holding the bow detaches from and store inside the base, making the whole thing portable. It even runs off solar or batteries if you need to work off-grid, which might be handy for quick repairs on the R/C flight line.

Speaking of R/C, check out these hot-wire cut foam airplane wings. And the completeness of this build gets us thinking about the potential for CNC foam cutters.

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Homemade Bulletproof Glass, Built And Tested

Hackers tend to stash away lots of stuff that seems useless, right up until it saves the day. This includes not just junk in our parts bin but brains full of tips and tricks for the shop. With that in mind, you might want to file away a few of the tips in [AvE]’s video of how he made bulletproof glass for a rainy day.

By his own admission, [AvE]’s video is a little disjointed, and the topic of the bulletproof glass is only covered at the beginning and again briefly at the end. Most of the video concerns the machining of a stout stand for the glass for testing on the range. There’s plenty to learn from the machining, though, and [AvE] is always good for a laugh, so the video is worth a watch. The bulletproof glass itself is part of a long-term project that [AvE] is releasing first to his Patreon patrons – a ridiculously over-built flashlight dubbed “The Midnight Sun”. His first two tries at laminating the Lexan discs were less that optimal, as both brands of cyanoacrylate glue clouded the polycarbonate. Stay tuned to the end of the video for the secret of welding Lexan together into an optically clear sandwich.

As for testing under fire, [AvE] sent the rig off to buddy [TAOFLEDERMAUS] for the hot lead treatment. The video after the break shows that the glass is indeed bulletproof, as long as the bullet in question is a .22LR. Not so much for the 9mm, though – that was a clear punch-through. Still, pretty impressive performance for homebrew.

If you want something that can stop an arrow, there’s a lot of materials science to be learned from the ancient Greeks.

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Old School Gauges Let You Know Which Way The Wind Blows

When your passion is a sport that depends on Mother Nature’s cooperation, you need to keep a close eye on weather conditions. With this in mind, and not one to let work distract him from an opportunity to play, [mechanicalsquid] decided to build a wind-monitoring gauge with an old-school look to let him know when the wind is right for kitesurfing.

old-school-meter-for-windBeing an aficionado of big engineering helped [mechanicalsquid] come up with a style for his gauge – big old dials and meters. We hesitate to apply the “steampunk” label to every project that retasks old technology, but it sure looks like a couple of the gauges he used could have been for steam, so the moniker probably fits here. Weather data for favorite kitesurfing and windsurfing locales is scraped from the web and applied to the gauges to indicates wind speed and direction. [mechanicalsquid] made a valiant effort to drive the voltmeter coil directly from the Raspberry Pi, but it was not to be. Servos proved inaccurate, so steppers do the job of moving the needles on both gauges. Check out the nicely detailed build log for this one, too.

For more weather station fun be sure to check out this meter-based weather station with a slightly more modern look. And for another build in the steampunk style, this vintage meter and Nixie power display is sure to impress.

Conductive Concrete Melts Snow And Ice

Winter sucks. Ice sucks. Shoveling sucks. What if roads, or your driveway, could get rid of snow and ice by themselves? (…with the help of our friend, the electron.)

A few days ago we shared a project about building an epic snow-melting system right into your driveway. But for obvious reasons, it’s not that easy to do — or cheap. But [Chris Tuan], an engineering professor at the University of Nebraska thinks he can change that.

He’s created his own special formula for conductive concrete. Which means you can turn the concrete into a resistive heat load. And this isn’t just a university research project that is going nowhere; it’s actually being trialed by the FAA for use in airports . There is a patch of it in Omaha undergoing testing right now.

And it’s actually not that complex. It consists of a mixture of 20% steel shavings and carbon particles, in a regular run-of-the-mill concrete. Apparently, this is enough to cause the entire patch of concrete to become conductive, meaning if you pump enough juice through it — it’d definitely melt some ice on top.

[Thanks Michael!]

Augmented Reality Becomes Useful, Real

The state of augmented reality is terrible. Despite everyone having handheld, portable computers with high-resolution cameras, no one has yet built ‘Minecraft with digital blocks in real life’, and the most exciting upcoming use for augmented reality is 3D Dungeons and Dragons. There are plenty of interesting things that can be done with augmented reality, the problem is someone needs to figure out what those things are. Lucky for us, the MIT Media Lab knocked it out of the park with the ability to program anything through augmented reality.

The Reality Editor is a simple idea, but one that is extraordinarily interesting. Objects all around you are marked with a design that can be easily read by a smartphone running a computer vision application. In augmented reality, these objects have buttons and dials that can be used to turn on a lamp, open a car’s window, or any other function that can be controlled over the Internet. It’s augmented reality buttons for everything.

This basic idea is simple, but by combining it by another oft-forgotten technology from the 90s, we get something really, really cool. The buttons on each of the objects can be connected together with a sort of graphical programming language. Scan a button, connect the button to a lamp, and you’re able to program the lamp with augmented reality.

The Reality Editor is already available on the Apple app store, and there are a number of examples available for people to start tinkering with this weird yet interesting means of interacting with the world. If you’ve ever wondered how we’re going to interact with the Internet of Things, there you have it. Video below.

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Bismuth Crystals Hold Magnet Suspended For 100 Years

[NightHawkInLight] has been playing around with the diamagnetic properties of bismuth. Diamagnetic materials get a lot of attention due to their strange ability to produce the opposite of the magnetic field going through them. In simpler terms, metals like iron are attracted to magnets; metals like bismuth repel them.

[NightHawkInLight] built his own interpretation of a common lab example used to demonstrate this remarkable property, a levitator. A levitator is made by sandwiching a magnet between two plates of diamagnetic material. One of the plates is given a magnetic field opposite of the magnet underneath it by a stronger magnet placed some distance away. When this is done, the magnet in between wants to repel away from the plate above, only to find that as it gets closer to the plate below it is equally repelled, creating a stable system.

Eventually the magnet above will need realignment, but [NightHawkInLight] assures us this is only once every 100 years. Video after the break. Continue reading “Bismuth Crystals Hold Magnet Suspended For 100 Years”