Hackaday regular [Mikey Sklar] is no stranger to body modifications. He enjoys tweaking his body in ways that help him with day to day tasks, including a ruler tattoo on his arm and an RFID chip embedded in the web of his hand. Lately, he has been toying around with a less invasive means of getting a better feel for magnetic fields in his surroundings.

Turned on to magnetic rings by a friend, he now wears an epoxy-coated rare earth ring every day, changing the way he interacts with the world. He says that besides the obvious ability to tell when he’s near iron-heavy material, he can also feel cell phone calls, as the speaker draws the ring closer while producing sound.

He says that holding the electric cord of his tea kettle gave him the biggest start, making him feel as if he had been electrocuted, minus the actual shock.

While it’s not the most high-tech hack, [Mikey] is quite happy with the “sixth sense” this reasonably price ring has been able to provide – we just might have to try it out ourselves.

[Andrey Mikhalchuk] built his own magnetic levitation device and you can too… if you have the patience. He’s not using electromagnets, like the Arduino levitator or the floating globe. Instead, a pair of ceramic ring magnets and a few hours are all it takes.

The base of his device is a couple of very large ring magnets that would most often be used in speakers. It’s hard to see them in the image above because there’s an inverted plastic container obscuring them. A second (or third depending on how you’re counting) ring magnet is selected because it is smaller than the circular void in the magnetic base. It’s impossible to simply balance the magnet in the air, but spinning it is a different story. By creating a perfectly balance magnetic top, then spinning it inside the magnetic field of the base, you can leave it floating in mid-air.

Check out the video after the break. It’s a neat effect, but you really do have to have a perfect setup for it to work. [Andrey] mentions that it takes a couple of hours to fine-tune. And if the ambient conditions change slightly, it throws the whole thing off.

When working in hard to reach areas, magnetized tools can mean the difference between wrapping things up quickly and spending way too much time blindly grasping for dropped screws. [Damir] wrote in to share a handy little contraption he built which allows him to magnetize and demagnetize his tools as needed.

While rubbing a magnet against the tip of a screwdriver will impart a weak and temporary magnetic field, he felt that a stronger more permanently magnetized tool was far more useful. It is pretty well known that subjecting metal to a direct current magnetic field will magnetize the item, and an alternating magnetic field will demagnetize the same object. [Damir’s] wand will perform either task with the simple flip of a switch.

He salvaged the motor coil from a broken washing machine and mounted it in a project box, along with a single-pole changeover switch. A small diode is used to perform rectification on the AC input, providing the DC current required for magnetizing his tools.

Every once in awhile we find the need for magnetized tools, so we think this would be great to have around the workshop.

Check out a quick video demo of the magnetizing wand after the jump.

You can get class credit for the coolest things these days. Take for instance, this Automatic Chessboard that [Brian] and [James] built for the final project in one of their classes this spring. We just looked at a robotic chess setup on Monday that used a gripper mounted on a gantry to move the pieces. This one’s a lot more user-friendly and borders on magical. That’s because the moving parts are all located below the board and could be hidden from view if a proper case were built around the edges.

There are two main components to this build. The first is a grid of reed switches that detect the moves made by a human. This works because each piece the human player uses has a weak magnet glued to the bottom which is just strong enough to actuate the reed switch and let the computer sense what move was just made. On the robotic side of things this works like a plotter. Each of the computer’s pieces has a metallic disc glued to the base. What basically amounts to a plotter under the board uses rare-earth magnets to grab the computer’s piece and drag it to the next playing position.

The use of two separate magnetic systems provides some interesting design challenges. You can see the device in action in the video after the break, and a full writeup and source code package is available at the blog linked at the top of this feature. But for your convenience we’ve also mirrored the PDF whitepaper after the break which lays bare all of the juicy details.

[Final_Project]

The theory behind speaker operation is pretty simple. There’s a coil that is attached to some type of diaphragm and a permanent magnet. When electrical signals pass through the coil a magnetic field is generated, and that field’s interaction with the permanent magnet causes the diaphragm to vibrate and create sound. But we’ve always assumed that the vibrating material must be stretched tight for this to work. [Hannah Perner-Wilson] proved us wrong by making this speaker out of fabric. It uses conductive tape as the coil on a heavy piece of canvas. The permanent magnet is resting on a table and for the demonstration the fabric is just laid on top.

Check out the video after the break to hear the sounds generated by this device as well as a design that uses conductive thread instead of tape. This gets us wondering if what we’re hearing is the result of the magnet vibrating against the tabletop? Let us know your thoughts, and if you’ve got any information about the paper-backed circuit (seen at 0:04 into the video) driving the speakers we’d love to hear about that too.

[Thanks Mowcius]

This collection of gauss weapons use rare earth magnets to accelerate projectiles to damaging speeds. They work using the same concepts as a coil gun, but instead of just one projectile travelling along a length of guide track, there are many projectiles that work in a chain reaction. A series of magnets are placed at equal distances along the track. Each has a couple of large ball bearings on the muzzle side of the magnet. The first ball bearing is fired using mechanical force – like a spring mechanism – and accelerates as it approaches the magnet due to the attractive force of that magnetic field. When it impacts the magnet it sends one of the ball bearings on the opposite side down the track where it will accelerate when it nears the next magnet in the chain. The weapon above achieves a final projectile speed of about 68 miles per hour, breaking six fluorescent tubes in a row on at the right side of the apparatus.

Still prefer rail guns that use electromagnets? Check out this gauss pistol kit that is about as powerful as a BB gun.

Above you see a solenoid being used as a digital scale. The magnetic field from the coil in the base levitates the platform above, where a load to be measured is place. This floating platform has a permanent magnet in it, hovering above a hall effect sensor in the base. As the distance between that magnet and the sensor changes, the measurable magnetic field changes as well. The hall effect sensor is linear so the measured value can easily be correlated with a weight. In the video after the break [Vsergeev] demonstrates the device using test weights to show off its 0.5 gram resolution. He thinks that with a few hardware improvements he could easily achieve 0.1g accuracy.

This hack’s old as dirt to be sure, but new to us and a great accomplishment. The plane above, which is meant to fly without an operator, has been given RC control thanks to parts from that little car. The transmitter and receiver pair are the obvious transplant, but how do you add steering to a $7 plane that wasn’t manufactured to have that feature? The tail was cut and reconnected with mylar hinges to turn it into a rudder. A rare earth magnet and a coil are also thrown into the mix to provide movement. Basically this is a simple solenoid where the coil pushes against the magnet when energized, actuating the rudder. This in combination with an upgraded motor allows for both speed control and yaw. It doesn’t look like you can control roll and pitch but what more can you really expect?

This would be a nice first step on that path to building an epic flying camera rig.

[Thanks Rob]

It has been recently discovered that all of the snap decisions that your brain makes on which hand to use to do simple tasks, such as picking up an object from a table, can now be automatically decided for you.  This is done using magnetic stimulation that is applied using transcranial magnetic stimulation or TMS.  This TMS will affect the brains ability to process motor movements and reduces the chances that the right hand will be chosen over the left.  This major discovery was found by PNAS (Proceedings of the National Academy of Sciences of the United States of America) who hopes to use this later on for rehabilitating stroke victims, making them using the limbs that may suffer from the event.  Here is to hoping that an in home product will be released in the future so children can become ambidextrous in everything they do.   It seems like that is a way off but it does seem more natural than most hacks to your body.

Via [iO9]

If you’re in need of eye surgery you might just find yourself strapped into this contraption. It’s a magnetic field generator used to manipulate a tiny, untethered probe. It’s called OctoMag and the idea is that a robot less than half a millimeter in size is injected into your vascular system and, through the use of those coils, it busts up blood clots in the small passages inside of the eye.

Once you’ve seen the clip after the break we’re sure you’ll agree that this is amazing technology. Nonetheless it makes us cringe to think of the procedure done on a living organism but we’re sure that fear will subside given time. For now this seems more like a treatment from A Clockwork Orange.

[Alexy Sha] has done this fantastic hack, where he modified a magnetic floating globe to be motorized and spin on a tilted axis. The original globe was simply levitating via a magnet mounted inside. Though you could spin it by hand, it wasn’t motorized, and actually floated completely vertically instead of being tilted.

[Alexy] wanted to take this idea further and make it automatically spin on a rotated axes. He built a rotation assembly that was basically a motor, hung off-center, attached at the center of the globe. He had to power it via a coil hidden in the base unit, so that it could remain light enough to float. He did a fantastic job and the final product seems like it is the true way it should have been sold.

Check out a video of it in action after the break. We actually like the spinning ring, when he’s testing it, just as much as the final spinning globe.

[Craig Carmichael] has been hard at work on his electric hub motor for cars. Unlike typical electrical vehicles the plan is to bypass the transmission, differential, and everything else all together by connecting directly to the hub of the wheel. The goal of giving greater thrust and still allowing the use of a gas engine if need be.

There’s really too much detail for us to even begin to try to explain the entire project in a short recap, but [Craig] builds the entire motor (from magnets to coil windings) and wires his own controller (from schematic to finished PCB), all while documenting the process thoroughly for those wishing to make their own.

This installation by artist [Nils Goudagnin] is a recreation of the hoverboard from Back to the Future II. We would like to see inside that plinth. We’ve seen levitating magnets before, but this is particularly stable. He says he is using lasers and a control system of some kind to stabilize it. Just to guess, we’d say that the lasers determine the distance of the board and an array of electromagnets below is adjusted to keep it level. Then again, we might be over thinking this. Even though it can’t be ridden, we’d love to have one around the office just to look at.

[Freeload] sent us his custom MagSafe adapter build for laptops. MagSafe for those unaware is Apples (patented) power adapters that prevent damage to laptops when the cord is accidentally yanked from the socket. While we’ve seen some custom versions before of MagSafes they were usually bulky, ugly, and used a ton of unremovable glue. We really like [Freeload's] because its quick, good looking, and the best part – completely removable without marks or damage. In short, an easy weekend project that could one day save your laptop.

Ah the beauty of watching molten solder pull SMD components into place. Yeah, we’ve seen it before, but for some reason it never gets old.

The glory days of wardriving are certainly behind us but if you’re still hunting in certain areas for access points you can leave the laptop at home. A homebrew program called Road Dog can turn your PSP into a WiFi search device. You must be able to run custom code to use this app.

Ferrofluid is our friend. But having grown up watching the Terminator and Hellraiser movies we can’t help being a little creeped out by the effects seen in this movie.

Follow along with the NASA astronauts in this 20 minute HD tour of the international space station. It’s a cramped place to live but we can’t help thinking that it looks incredibly clean. After all, where would the dirt come from?

How are your woodworking skills?  Can you take a wooden block and turn it on a lathe until you have a lampshade 1/32″ thick? We’d love to see how these are made, but imagine the artist’s reaction when hours of labor are ruined by a minuscule amount of misplaced pressure on a carving tool. Patience, we’ll learn it some day!

This video from the past that is about the future of  travel does leave us wondering why our cars don’t have built-in radar for poor visibility? We’ve already realized the rear-view-mirror-tv-picture, but we’re going to need your help before the flying police/fire/ambulance-mobile is a common sight. Oh, the fun of seeing a high-tech push-button selector 3:30 into the video. Perhaps the touch-screen was a bit beyond the vision of the time.

Sometimes you have so many servants you need to find creative things for them to do. Only the most discriminating of the super-rich employ a person whose sole responsibility is to erase and redraw the hands of a clock each minute. This video is obviously a result of the global recession as the live time-keeper has been let go; a looping recording took his job!

Last time we checked in with [Marco Tempest] he was syncing video over multiple iPhones. Now he’s at it again with an augmented reality setup. A camera picks up some IR LEDs in a canvas and translates that into information for a video projector. We’d call this a trick, but it’s certainly not magic.