Beverage Holder of Science

The folks at [K&J Magnetics] have access to precise magnetometers, a wealth of knowledge from years of experience but when it comes to playing around with a silly project like a magnetic koozie, they go right to trial and error rather than simulations and calculations. Granted, this is the opposite of mission-critical.

Once the experimentation was over, they got down to explaining their results so we can learn more than just how to hold our beer on the side of a toolbox. They describe three factors related to magnetic holding in clear terms that are the meat and bones of …read more

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A Brushless Motor on a PCB, Made from PCB

At Hackaday, we really appreciate it when new projects build on projects we’ve featured in the past. It’s great to be able to track back and see what inspires people to pick up someone else’s work and bring it to the next level or take it down a totally new path.

This PCB brushless motor is a great example of the soft collaboration that makes the Hackaday community so powerful. [bobricius] says he was inspired by this tiny PCB BLDC when he came up with his design. His write-up is still sparse at this point, but it looks like his …read more

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Print a Sacrificial Magnet Square

Here’s your quick and dirty hack for the day. Sometimes you just need something that will work for what you’re trying to do, and you don’t want to go through the motions of doing what’s prescribed. When this happens, it’s a cheap, disposable tool that fits the bill. No, we’re not talking about Harbor Freight—we mean those need-driven tools you make yourself that get the job done without fuss. If you’re really lucky, you can use them a couple of times before they break.

This is one of those tools. [Jake’s Workshop] wanted to be able to quickly tack a …read more

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Electromagnet-Powered Pendulum

We’re always happy to see hackers inspired to try something different by what they see on Hackaday. To [SimpleTronic] has a project that will let you stretch your analog electronics skills in a really fun way. It’s an electromagnet pendulum analog circuit. Whether you’re building it, or just studying the schematics, this is a fun way to brush up on the non-digital side of the craft.

The pendulum is a neodymium magnet on the head of a bolt, dangling on a one foot aluminium chain. Below, a Hall Effect sensor rests atop an electromagnet — 1″ in diameter, with 6/8″ …read more

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Low-Power Motor Can Run for Years on a Coin Cell

Can you run an electric motor for two years on a single lithium coin cell? [IamWe] figured out how to do it, and even though his donut motor doesn’t look like any motor we’ve ever seen before, it’s a pretty solid lesson in low-current design.

The donut motor is really just a brushless DC motor with a sign-pole stator and a multi-pole rotor. The frame of the motor is built from a styrofoam donut, hence the motor’s name. The rotor is a styrofoam sphere with neodymium magnets embedded around its equator. A sharpened bicycle spoke serves as an axle, and …read more

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Over-Engineered Mailbox Flag machined using Under-Engineered Mini-Lathe

[Tim Nummy] used his cheap, Chinese, bench mini-lathe to make a non-terrible mailbox flag holder (YouTube video, embedded below). Tim posts videos on his channel about garage hobby projects, many of which are built using his mini-lathe, often based on suggestions from his followers. One such suggestion was to do something about his terrible mailbox flag – we’re guessing he receives a lot of old-school fan mail.

He starts off by planning the build around 1 ¼ inch aluminum bar stock, a 688 bearing, three neodymium magnets and some screws. The rest of it is a “think and plan as …read more

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Powerful, Professional Brushless Motor from 3D-Printed Parts

Not satisfied with the specs of off-the-shelf brushless DC motors? Looking to up the difficulty level on your next quadcopter build? Or perhaps you just define “DIY” as rigorously as possible? If any of those are true, you might want to check out this hand-wound, 3D-printed brushless DC motor.

There might be another reason behind [Christoph Laimer]’s build — moar power! The BLDC he created looks more like a ceiling fan motor than something you’d see on a quad, and clocks in at a respectable 600 watts and 80% efficiency. The motor uses 3D-printed parts for the rotor, stator, and …read more

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