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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Invasion of the Tiny Magnetic PCB Vises

[Proto G] recently wrote in to share a very slick way of keeping tabs on all the tiny PCBs and devices that litter the modern electronics workbench. Rather than a big bulky PCB vise for each little board, he shows how to make tiny grippers with magnetic bases for only a couple bucks each. Combined with a sheet metal plate under an ESD mat, it allows him to securely position multiple PCBs all over his workspace.

The key to this hack is the little standoffs that are usually used to mount signs to walls. These already have a clamping action …read more

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Absolute 3D Tracking With EM Fields

[Chris Gunawardena] is still holding his breath on Valve and Facebook surprising everyone by open sourcing their top secret VR prototypes. They have some really clever ways to track the exact location and orientation of the big black box they want people to strap to their faces. Until then, though, he decided to take his own stab at the 3D tracking problems they had to solve. 

While they used light to perform the localization, he wanted to experiment with using electromagnetic fields to perform the same function. Every phone these days has a magnetometer built in. It’s used to figure …read more

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A Tech That Didn’t Make It: Sound On Stainless Steel Wire

For a brief period in the 1940’s it might have been possible for a young enamored soul to hand his hopeful a romantic mix-spool of wire. This was right before the magnetic tape recorder and its derivatives came into full swing and dominated the industry thoroughly until the advent of the compact disk and under a hundred kilogram hard disk drives. [Techmoan] tells us all about it in this video.

The device works as one would expect, but it still sounds a little crazy. Take a ridiculously long spool of steel wire the size of a human hair(a 1 hour …read more

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