Easy Toy Hack Makes Floating Death Star

August 14, 2016 by Al Williams 2 Comments

It always seems odd to us that magnetic levitation seems to only find use in big projects (like trains) and in toys. Surely there’s a practical application that fits on our desktop. This isn’t it, but it is a cool way to turn a cheesy-looking levitating globe into a pretty cool Star Wars desk toy.

As projects go, this isn’t especially technically challenging, but it is a great example of taking something off the shelf and hacking it into something else. The globe covering came off, revealing two hemispheres. A circular hole cut out and inverted provides the main weapon. Some internal lighting and small holes provide light. Some fiber optic sanded and tinted green make the weapon fire. The rest is all in the painting.

There’s even a tiny imperial ship orbiting the killer man-made (or is that Sith-made) moon. If you want a bigger challenge, you might try bamboo. Or you can go minimalist and let your eyes and brain do most of the work.

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Mag Lev Without The Train (But With An FPGA)

June 26, 2016 by Al Williams 4 Comments

It always surprises us that magnetic levitation seems to have two main purposes: trains and toys. It is reasonably inexpensive to get floating Bluetooth speakers, globes, or just floating platforms for display. The idea is reasonably simple, especially if you only care about levitation in two dimensions. You let an electromagnet pull the levitating object (which is, of course, ferrous). A sensor detects when the object is at a certain height and shuts off the magnet. The object falls, which turns the magnet back on, repeating the process. If you do it right, the object will reach equilibrium and hover near the sensor.

Some students at Cornell University decided to implement the control loop to produce levitation using an Altera FPGA. An inductive sensor determined the position of an iron ball. The device uses a standard proportional integral derivative (PID) control loop. The control loop and PWM generation occur in the FPGA hardware. You can see a video of their result, below.

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Magnetic Levitation With Arduino

November 2, 2015 by Will Sweatman 7 Comments

Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was able to balance a high density neodymium magnet in midair. He pulled off this tricky project using a set of four coils he got off of Taobao (the Chinese version of eBay), a hall effect sensor, and a handful of current regulation ICs.

The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is straightforward. It appears he uses a potentiometer for a rough regulation of the current going to the coils, doing the fine tuning in the code which can be found here (.RAR direct download).

We’ve seen magnetic levitation here before, and this project adds to the list of successful techniques to accomplish this difficult project.

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Maglev, Submersibles, And More At Maker Faire Detroit

July 30, 2015 by Ethan Zonca 7 Comments

This past weekend the Maker Faire returned to the motor city. While it seemed a bit smaller than previous years, the event still brought in a ton of awesome makers from the metro Detroit area and beyond.

Although we don’t feature too many woodworking projects, there were quite a few woodworkers at the Faire with projects ranging from custom longboards pressed with a home built iron mold to DIY kayaks with elaborate wooden skeletons built by a local group of Michigan kayak builders. The kayaks were quite impressive: hand sewn nylon panels are wrapped around custom frames made from steamed white oak. It’s great to speak with the makers about the specialized skills needed for kayak building.

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Building A Magnetic Levitating Quadcopter

October 24, 2014 by Brian Benchoff 82 Comments

hover Three days ago on October 21, 2014 it was announced to the world the Back to the Future hoverboard was real. It’s a Kickstarter, of course, and it’s trending towards a $5 Million dollar payday for the creator. Surprisingly for a project with this much marketing genius, it’s a real, existing device and there’s even a patent. From the patent, we’re able to glean a few details of how this hoverboard/magnetic levitation device works, and in our post on the initial coverage, we said we’d be giving away some goodies to the first person who can clone this magnetic levitation device and put it up on hackaday.io.

[jellmeister] just won the prize. It’s somewhat cheating, as he’s had his prototype hoverboard working in July, and demoed a more advanced ‘upside-down quadcopter’ device at the Brighton Mini Maker Faire in September. Good on ‘ya [jelly]. You’re getting a gift card for the hackaday store.

hover Like the Kickstarter hoverboard, [jelly] is using an array of magnets rotating in a frame above a non-ferrous metal. For the initial test, eight neodymium magnets were arranged in a frame, suspended over 3/4″ aluminum plate, and spun up with a drill. With just this simple test, [jelly] was able to achieve 2kg of lift at 1cm and 1kg of lift at 1 inch of separation. This test also provided some valuable insight on what the magnets do to the aluminum or copper; the 3kg aluminum plate was nearly spinning, meaning if this device were to be used on small plates, counter-rotating pairs of magnetic lifters would need to be used.

The test rig then advanced to two pairs of rotors with standard hobby brushless motors, but stability was a problem; the magnetic rotors provided enough lift, but it would quickly fall over. To solve this problem, [jellmeister] took a standard quadcopter configuration, replaced the props with magnetic rotors, and successfully hovered it above a sheet of aluminum at the Brighton Maker Faire.

Since [jellmeister] has actually built one of these magnetically levitating hoverboards, he has a lot more data about how they work than an embargoed press release. The magnetic rotor hoverboard will work on aluminum as well as copper, but [jell] suspects the Kickstarter hoverboard may be operating right at the edge of its performance, necessitating the more efficient copper half pipe. The thickness of the non-ferrous plate also makes a difference, with better performance found using thicker plates. No, you bojo, hoverboards don’t work on salt water, even if you have pow-ah.

So there ‘ya go. That’s how you build a freakin’ hoverboard. [jellmeister]’s design is a little crude and using a Halbach array for the magnetic rotors should improve efficiency. Using a 3D printed rotor design is a stroke of genius, and we’ll expect a few more quad-magnetic-levitating-things to hit the tip line in short order.

Demos of [jellmeister]’s work below.

Oh. These things need a name. I humbly submit the term ‘Bojo’ to refer to any device that levitates though rotating magnets and eddy currents.

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The Hoverboard You Can Build At Home

October 21, 2014 by Brian Benchoff 160 Comments

Press embargoes lifted today, heralding the announcement of the world’s first hoverboard. Yes, the hovering skateboard from Back to the Future. It’s called the Hendo hoverboard, it’s apparently real, and you can buy one for $10,000. If that’s too rich for your blood, you can spend $900 for a ‘technology demonstrator’ – a remote-controlled hovering box powered by the same technology.

Of course the world’s first hoverboard is announced to the world as a crowd funding campaign, so before we get to how this thing is supposed to work, we’ll have to do our due diligence. The company behind this campaign, Arx Pax Labs, Inc, exists, as does the founder. All the relevant business registration, biographical information, and experience of the founder and employees of Arx Pax check out to my satisfaction. In fact, at least one employee has work experience with the innards of electric motors. At first glance, the company itself is actually legit.

The campaign is for a BttF-style hoverboard, but this is really only a marketing strategy for Arx Pax; the hoverboards themselves are admittedly loss leaders even at $10,000 – the main goal of this Kickstarter is simply to get media attention to the magnetic levitation technology found in the hoverboard. All of this was carefully orchestrated, with a ‘huge event’ to be held exactly one year from today demonstrating a real, working hoverboard. What’s so special about demoing a hoverboard on October 21, 2015?

I defy anyone to come up with a better marketing campaign than this.

The meat of the story comes from what has until now been a scientific curiosity. Everyone reading this has no doubt seen superconductors levitated off a bed of magnets, and demonstrations of eddy currents are really just something cool you can do with a rare earth magnet and a copper pipe. What [Greg Henderson] and Arx Pax have done is take these phenomena and turned them into a platform for magnetic levitation.

According to the patent, the magnetic levitation system found in the Hendo hoverboard works like this:

One or more electric motors spin a series of rotors consisting of an arrangement of strong permanent magnets.
The magnets are arranged in a Halbach array that enhances the magnetic field on one side of the array, and cancels it on the other.
By placing the rotors over a conductive, non-ferrous surface – a sheet of copper or aluminum, for example – eddy currents are induced in the conductive surface.
These eddy currents create a magnetic field that opposes the magnetic field that created it, causing the entire device to levitate.

That’s it. That’s how you create a real, working hoverboard. Arx Pax has also developed a method to control a vehicle equipped with a few of these hover disks; the $900 ‘Whitebox’ technology demonstrator includes a smart phone app as a remote control.

If you’re still sitting in a steaming pile of incredulity concerning this invention, you’re in good company. It’s a fine line between being blinded by brilliance and baffled by bullshit, so we’re leaving this one up to you: build one of these devices, put it up on hackaday.io, and we’ll make it worth your while. We’re giving away some gift cards to the Hackaday store for the first person to build one of these hoverboards, preferably with a cool body kit. The Star Wars landspeeder has already been done, but the snowspeeder hasn’t. Surprise us.

Levitating Speaker Plays Back Eerie Recordings

September 4, 2014 by James Hobson 50 Comments

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.

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