The Magic that Goes into Magnets

Every person who reads these pages is likely to have encountered a neodymium magnet. Most of us interact with them on a daily basis, so it is easy to assume that the process for their manufacture must be simple since they are everywhere. That is not the case, and there is value in knowing how the magnets are manufactured so that the next time you pick one up or put a reminder on the fridge you can appreciate the labor that goes into one.

[Michael Brand] writes the Super Magnet Man blog and he walks us through the high-level steps …read more

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Dollar Store PCB Holder System

As you get into electronic fabrication and repair, one of the first things you realize is how hard it can be to hold a PCB still while you work on it. Securing them is difficult due to their very nature: they’re often weird shapes, quite fragile, and of course need to be electrically isolated. If you don’t mind spending the money, and have the time to wait on it getting delivered, you can order some nice purpose-built systems for holding PCBs online. But what if you need something fast and cheap?

[Paul Bryson] might have the solution for you. On …read more

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Coming Back to Curving Bullets

What do you do when you have time, thousands of dollars worth of magnets, and you love Mythbusters? Science. At least, science with a flair for the dramatics. The myth that a magnetic wristwatch with today’s technology can stop, or even redirect, a bullet is firmly busted. The crew at [K&J Magnetics] wanted to take their own stab at the myth and they took liberties.

Despite the results of the show, a single magnet was able to measurably alter the path of a projectile. This won’t evolve into any life-saving technology because the gun is replaced with an underpowered BB …read more

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Magnetic Spheres Line Up for Rotary Encoder Duty

When it comes to rotary encoders, there are plenty of options. Most of them involve putting a credit card number into an online vendor’s website, though, and that’s sometimes just not in the cards. In that case building your own, like this encoder using magnetic spheres, is a pretty cool way to go too.

If he’d had less time to spare, we imagine [Antonio Ospite] would have gone for a commercial solution rather than building an encoder from scratch. Then again, he says his application had noise considerations, so maybe this was the best solution overall. He had some latching …read more

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DIY Magnetic Actuator, Illustrated And Demonstrated

Electromagnetic actuators exert small amounts of force, but are simple and definitely have their niche. [SeanHodgins] took a design that’s common in flip-dot displays as well as the lightweight RC aircraft world and decided to make his own version. He does a good job of explaining and demonstrating the basic principles behind how one of these actuators works, although the “robotic” application claimed is less clear.

It’s a small, 3D printed lever with an embedded magnet that flips one way or another depending on the direction of current flowing through a nearby coil. Actuators of this design are capable of …read more

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3D-Printer Gets Hot-Swappable Hot-Ends

3D printers can be hacked into a multitude of useful machines, simply by replacing the filament extruder with a new attachment such as a laser engraver or plotter.

However, [geggo] was fed up with re-wiring and mounting the printhead/tool every time he wanted to try something new, and set out to design a modular printhead system for next-level convenience. The result? A magnetic base-plate, allowing a 3D printer to become a laser engraver within a matter of seconds. This new base-plate mounts onto the existing ball bearings and provides a sturdy place for attachments to snap to – with room …read more

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You’ve Never Seen A Flipping Eyeball Like This One!

Inspired by some impressive work on textile flip-bit displays, and with creative steampunk outfits to create for Christmas, [Richard Sewell] had the idea for a flippable magnetic eye in the manner of a flip-dot display. These devices are bistable mechanical displays in which a magnet is suspended above a coil of wire, and “flipped” in orientation under the influence of a magnetic field from the coil.

In [Richard]’s case the eyeball was provided by a magnetic bead with a suitable paint job, and the coil was a hand-wound affair with some extremely neat lacing to keep it all in place. …read more

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Keeping Magnetized Marbles from Stopping the Music

Take a couple of thousand steel balls, add a large wooden gear with neodymium magnets embedded in it, and what do you get? Either the beginnings of a wonderful kinetic music machine, or a mess of balls all stuck together and clogging up the works.

The latter was the case for [Martin], and he needed to find a way to demagnetize steel balls in a continuous process if his “Marble Machine X” were to see the light of day. You may recall [Martin] as a member of the band Wintergatan and the inventor of the original Marble Machine, a remarkable …read more

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Keeping Magnetized Marbles from Stopping the Music

Take a couple of thousand steel balls, add a large wooden gear with neodymium magnets embedded in it, and what do you get? Either the beginnings of a wonderful kinetic music machine, or a mess of balls all stuck together and clogging up the works.

The latter was the case for [Martin], and he needed to find a way to demagnetize steel balls in a continuous process if his “Marble Machine X” were to see the light of day. You may recall [Martin] as a member of the band Wintergatan and the inventor of the original Marble Machine, a remarkable …read more

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Flying the Friendly Skies with A Hall Effect Joystick

There are plenty of PC joysticks out there, but that didn’t stop [dizekat] from building his own. Most joysticks mechanically potentiometers or encoders to measure position. Only a few high-end models use Hall effect sensors. That’s the route [dizekat] took.

Hall effect sensors are non-contact devices which measure magnetic fields. They can be used to measure the position and orientation of a magnet. That’s exactly how [dizekat] is using a trio of sensors in his design. The core of the joystick is a universal joint from an old R/C car. The center section of the joint (called a spider) has …read more

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