We’re replacing “holy moley” in our vocabulary. Levitating globs of molten aluminum are that much more amazing. It’s not that we couldn’t believe it would work — we understand the physics after the fact. It’s just that we never would have thought to build an induction forge that can simultaneously melt and levitate a chunk of aluminum. (Video embedded below.)
[imsmoother] has had plans for 3 kW and 10 kW induction heaters online since at least 2011, and we’re wondering how we haven’t covered it before. Anyway, in the video, he’s using the smaller of the two to melt a chunk of aluminum. Continue reading “Flying Balls of Molten Aluminum!”
Finally our childhood dreams of a working tractor beam are coming to fruition! It’s called acoustic levitation and it actually uses highly concentrated sound waves to float small objects by essentially creating an acoustic force field.
The concept is nothing new, in fact we first covered it back in 2014 — but since then they’ve made leaps and bounds in their research. Back then they could just levitate dust. Now we’re moving onto small objects, like googly-eyes! It’s perceivable that with powerful enough speakers, larger objects will soon be harnessed…
Continue reading “Even if I could take off, I could never get past the tractor beam!”
Let’s face it, levitating anything is pretty fascinating — especially when you think there should be wires. This project puts a new spin on magnetic levitation by using a PID controller to levitate a speaker while it plays music!
It uses the standard levitation setup — an electromagnet, a permanent magnet, and a hall effect sensor. A microcontroller implements the PID system, varying the current supplied to the electromagnet to keep the speaker floating at just the right height. Music is wirelessly transmitted to the speaker via Bluetooth, but unfortunately the speaker’s power is not. It features a small lithium ion battery which has a run-time of around 5 hours before it has to be recharged manually.
As you’ll notice in the following video, having a floating speaker has a pretty interesting effect — especially when it starts spinning.
Continue reading “Levitating Speaker Plays Back Eerie Recordings”
[Jacob] has put a slightly new twist on the levitating ball trick with his ping-pong ball levitation machine. We’ve all seen magnetic levitation systems before. Here on Hackaday, [Caleb] built a Portal gun which levitated a Companion Cube. Rather than go the magnetic route, [Jacob] levitated a ping-pong ball on a cushion of air.
Now, it would be possible to cheat here, anyone who’s seen a demonstration of Bernoulli’s principle knows that the ball will remain stable in a stream of air. [Jacob] proves that his system is actually working by levitating ping-pong balls with different weights.
A Parallax Ping style ultrasonic sensor measures the distance between the top of the rig and the levitating ball. If the ball gets above a set distance, [Jacob’s] chipKit based processor throttles down his fans. If the ball gets too low, the fans are throttled up. A software based Proportional Integral Derivative (PID) loop keeps the system under control. A graph of the ball distance vs fan speed is displayed on an Android tablet connected to the controller via USB.
When [Jacob] switches a heavy ball for a light one, the lighter ball is pushed beyond the pre-programmed height. The controller responds by reducing the fan speed and the ball falls back. Who said you can’t do anything good with a box of corn dogs?
Continue reading “The Old Ping-Pong Ball Levitation Trick”
Wow. [Yoichi Ochiai], [Takayuki Hoshi] and [Jun Rekimoto] are researchers from the University of Tokyo and the Nagoya Institute of Technology, and they have just learned how to airbend.
Using a series of standing ultrasound waves, it is possible to suspend small particles at the sound pressure nodes. The acoustic axis of the ultrasound beam is parallel to gravity, which also allows the objects to be manipulated along the fixed axis by varying the phase or frequencies of the sound. By adding a second ultrasound beam perpendicular to the first it is possible to localize the pressure node, or focal point, and levitate small objects around a 2D plane.
In their demonstrations they float foam particles, a resistor, an LED, they show off the waves using a piece of dry ice, and even manage to float a small screw.
Sound like crazy talk? Just watch the video.
Continue reading “3D Acoustic Manipulation: Seemingly-Unreal Levitation Using Soundwaves”
These water droplets are not falling; they’re actually stuck in place. What we’re seeing is the effects of an acoustic levitator. The device was initially developed by NASA to simulate microgravity. Now it’s being used by the pharmaceutical industry do develop better drugs.
The two parts of the apparatus seen in the image above are both speakers. They put out a sound at about 22 kHz, which is beyond the human range of hearing. When precisely aligned they interfere with each other and create a standing wave. The droplets are trapped in the nodes of that wave.
So are these guys just playing around with the fancy lab equipment? Nope. The levitation is being used to evaporate water from a drug without the substance touching the sides of a container. This prevents the formation of crystals in the solution. But we like it for the novelty and would love to see someone put one of these together in their home workshop.
Don’t miss the mystical demo in the clip after the break.
Continue reading “Acoustic levitation of water droplets”
It would be really fun to do an entire hallway of these levitating wireless lights. This a project on which [Chris Rieger] has been working for about six months. It uses magnetic levitation and wireless power transfer to create a really neat LED oddity.
Levitation is managed by a permanent magnet on the light assembly and an electromagnetic coil hidden on the other side of the top panel for the enclosure. That coil uses 300 meters of 20 AWG wire. A hall effect sensor is used to provide feedback on the location of the light unit, allowing the current going to the coil to be adjusted in order to keep the light unit stationary. When working correctly this draws about 0.25A at 12V.
Wireless power transfer is facilitated by a single large hoop of wire driven with alternating current at 1 MHz. This part of the system pulls 0.5A at 12V, bringing the whole of the consumption in at around 9 Watts. Not too bad. Check out [Chris’] demo video embedded after the break.
A similar method of coupling levitation with power transfer was used to make this floating globe rotate.
Continue reading “Levitating lightbulb does it all with no wires”