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.
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.
Your hamster lives to good life, with food delivery and a maid service that cleans up after him. [DanF] helped to brighten up this hamster’s life even more by improving its exercise equipment and giving it a small night-light as well. This project adds a low RPM alternator to the hamster wheel.
The first part of the process was to reduce energy lost to friction by fitting the wheel with a bearing. From there a ring of permanent magnets was added which will pass by a stationary coil and induce a current. It works, but unfortunately there’s not enough power generated to charge a battery. That means the light is only on when the hamster is running. But maybe you can figure out a way to use a super-capacitor like we saw in that exercise bike hack.
One nice finishing touch to the setup is a bicycle computer to track how much time was sent on the wheel, and the distance traveled.
Slow day at the office? Here’s a trick that’ll make your coworkers smile. Dangerously Fun has a guide to build a homopolar motor from a battery, copper wire, and magnet. A homopolor motor doesn’t rely on electromagnets in an armature changing their polarity to force a rotation movement compared to stationary magnets. Instead, they use an electrical current’s orientation to a magnetic field to provide a repulsive or rotational force. In this implementation, the current moves through a loops of copper wire from one pole of a battery to the other. A rare-earth magnet on one pole of the battery provides the magnetic field.
After the break we’ve embedded video of this simple example as well as a few more complex homopolar examples such as a five speed version. The motor in action certainly brings a smile to our faces and places this firmly in the useless machines family of hacks.
Continue reading “Homopolar motor”