Misc Hacks

4194 Articles

Finding A Way To Produce Powerful Motors Without Rare Earths

January 13, 2026 by 23 Comments

The electric vehicle revolution has created market forces to drive all sorts of innovations. Battery technology has progressed at a rapid pace, and engineers have developed ways to charge vehicles at ever more breakneck rates. Similarly, electric motors have become more powerful and more compact, delivering greater performance than ever before.

In the latter case, while modern EV motors are very capable things, they’re also reliant on materials that are increasingly hard to come by. Most specifically, it’s the rare earth materials that make their magnets so good. The vast majority of these minerals come from China, with trade woes and geopolitics making it difficult to get them at any sort of reasonable price. Thus has sprung up a new market force, pushing engineers to search for new ways to make their motors compact, efficient, and powerful.

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The best-practice wind tunnel (above) vs a compact version (below)

Optimizing A Desktop, 3D Printed Wind Tunnel

January 12, 2026 by 2 Comments

You’ve heard of wind tunnels– get some airflow going over a thingy, put some some smoke on, and voila! Flow visualization. How hard could it be? Well, as always, the devil is in the details and [toast] is down in there with him with this Hot-Wheels sized wind tunnel video.

To get good, laminar flow inside of a wind tunnel, there are important ratios to be followed– the inlet and outlet diameters must relate to the interior size to get the correct slope on the contraction and exhaust cones. You need a flow straightener on both ends. All of it can be easily 3D printed, as [toast] shows, but you have to know those design rules and pay attention to, which [toast] does… this time. One of his “don’t do this” examples in this video is previous build of his where he did not follow all the rules, and the difference is clear.

Now, unless you’re hooked on flow visualizations —guilty— or are a Hot-Wheels aficionado, since that’s what this wind tunnel is sized for, you probably won’t rush to gumroad to buy [toast]’s STLs. On the other hand, if you pay attention to the lessons [toast] has learned in this video you can apply them to wind tunnels of whatever size and construction technique you need, be it cardboard or junk box plastic and get a more stable result.

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A man is shown standing in a wooded area, in front of a stone wall, facing toward the camera. To the left of him, on a rock, are a selection of compasses. Further to the left, another scene is shown, of two compasses. One has a brass-colored metal ring around it, and a timer above it reads 00:04:19. A timer above the other reads 01:47:02.

A New Kind Of Inductively-damped Compass

January 11, 2026 by 36 Comments

At some point during our primary school careers, most of us probably constructed a simple compass, often by floating a magnetized needle on a cork in a cup of water. The water in such a configuration not only lets the needle spin without friction, but also dampens out (so to speak) the needle’s tendency to swing back and forth across the north-south line. Liquid-filled compasses use the same principle, but even well-made compasses can develop bubbles when exposed to temperature or pressure variations. Rather than accept this unsightly state of affairs, [The Map Reading Company] designed a new kind of liquid-free, inductively-damped compass.

It’s hard to design a compass that settles quickly, even if it uses a strong magnet, because the Earth’s own magnetic field is just so weak, and the stronger the internal magnet is, the more likely it is to be thrown off by nearby magnetic objects. As a result, they tend to swing, overshoot, and oscillate around their final orientation for some time. Most compasses use liquid to damp this, but a few, mostly military compasses, use a conductive baseplate instead: as the magnet moves, it induces eddy currents in the baseplate, which create a weak magnetic field opposing its motion, slowing the magnet down. Inductively-damped compasses don’t get bubbles, but they don’t let you see a map through the baseplate. [The Map Reading Company] dealt with this by making the baseplate transparent and surrounding the compass needle with a ring of high-conductivity copper alloy. This gave him a clear baseplate compass for easy map reading which would never develop bubbles. It’s a simple hack, and should be easy to replicate, but it still seems to be a new design. In fact, [The Map Reading Company] is releasing most of the design to the public domain. Anyone can build this design.

If this prompts your interest in compasses, check out the Earth inductor compass. We’ve also seen a visualization of the eddy currents that damp these oscillations, and even seen them used to drive a bike.

Thanks to [Mel] for the tip!

The blower and a smaller motor than what's actually driving it.

Electric Snowblower Clears The Way With Hobby Parts

January 8, 2026 by 26 Comments

If you live in snow country and own a home, you either have a snowblower or wish you did. The alternatives are either an expensive and potentially unreliable plow service, or back-breaking (and heart-attack inducing) shoveling. [RCLifeOn] was one of those people in the second category, until he decided to do something about it: electrifying a scrap snowblower with a blown engine. 

The usual brushless DC motors and electronic speed controllers [RCLifeOn] has on hand to get his R/C life on with don’t quite have enough oomph to handle both functions of a snowblower. For those of you cursed to live in warmer climes, the modern snowblower is both self-propelled via its twin wheels, and generally has a two-stage powered snow-removal “blower” consisting of an auger to break up the snow and an impeller to blast it out of the machine and many meters off the driveway. On the traditional gas-powered models, these are both powered via belts off the same motor, but that wasn’t going to work.

He kept the belts, and simply used a pair of motors, each with their own ESCs that are controlled via oversized thumb wheels on the handles. The belts couple to the motors with 3D printed pulleys. Belt tension is achieved in the case of the wheels through a simple and sensible shimming arrangement. In the case of the blower motor, he uses a 3D printed adjustable mount to get the appropriate tension. To help it hold long-term (given the issues with creep in 3D prints) he’s got a bearing on a second mount opposite the motor.  It holds up for his demo, which consists of clearing a driveway of 10cm of snow and then plowing through a pile larger than the mouth of the machine. In other words: it works.

The build, as unfortunately common on YouTube, is shy on specific details– but in this case that’s fine. Even if he’d open-sourced everything and posted STEP or STL files, it wouldn’t save much time since you’d pretty well have to re-engineer the build to fit your own snowblower, if you were so inclined. As with many hacks of this nature, the point of sharing it is to show how easy it is and provide the inspiration. As the cartoons used to say, “knowing is half the battle.”

If one was to re-implement this hack, we could not encourage you strongly enough to put in the standard dead-man’s switch, a feature commercial snowblowers share with things like lawnmowers. As annoying as it is to hang onto with frozen fingers, that safety feature is there for a reason.

If your driveway is short, you can save on gas and fuel costs with an extension cord. Or you could just stay inside and do the job by remote control, but that comes with its own pitfalls.

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Old FM Radio Upcycled Into Classy Bluetooth Speaker

December 23, 2025 by 26 Comments

[Distracted by Design] loves gear from the 1980s, though some of it isn’t as useful as it used to be. He happened across a cheap old FM radio with a great look, but wanted to repurpose it into something more modern. Thus, he set about turning this cheap piece of old electronics into a stylish Bluetooth speaker.

All of the original electronics were stripped out, while the original speaker was kept since it neatly fit the case. Electronically, the build relies on a Bluetooth module harvested from an existing speaker. 3D-printed bracketry was used to fasten it neatly into place inside the radio housing, with the buttons neatly presented where the original radio had its tone and volume controls. Power is via an internal lithium-ion battery, charged over USB-C thanks to an off-the-shelf charging module.

Where the build really shines, though, is the detailing. The original cheap plastic handle was replaced with a CNC-machined wooden piece, bolted on with machined aluminium side plates. Similarly, the original clear plastic tuning window was replaced with another tasteful piece of wood that dropped perfectly into place. At the back, the charge port is nicely integrated. Where the radio formerly had a removable door for the power cable storage, it now has a machined aluminium plate hosting the USB-C charge port. Little 3D-printed button actuators were also used to integrate the Bluetooth module’s controls into the case.

It’s a very stylish build, overall. Perhaps the one area it’s a let down is in the sound quality. The ancient speaker simply doesn’t sound great compared to modern Bluetooth speakers and their finely-tuned, bassy audio. However, this isn’t necessarily a bad thing—sometimes it’s nice to have an audio source with a limited frequency response. It can be nice for use in an area where you may want to be able to easily speak over the music.

If you want to build a Bluetooth speaker of your own, you might like to whip up an open-source design from scratch. Video after the break.

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Shoot Instax Film In A Polaroid Camera With The Aid Of Tape

December 21, 2025 by 5 Comments

Polaroid cameras have been very popular for a very long time and are especially hot gifts this year. Fresh film is easy to find but relatively expensive. In contrast, Fuji’s Instax line of instant film and cameras aren’t as well established, but the film is easy to find and cheap. You might like to shoot cheap Instax film in your Polaroid camera. Thankfully, [Nick LoPresti] figured out how to do just that.

You can’t just slam an Instax cassette in an old Polaroid camera and expect it to work. The films are completely different sizes, and there’s no way they will feed properly through the camera’s mechanisms at all. Instead, you have to get manual about things. [Nick] starts by explaining the process of removing Instax film sheets from a cassette, which must be done without exposure to light if you want the film to remain useful. Then, if you know what you’re doing, you can tape it in place behind the lens of an old-school Polaroid camera, and expose it as you would any other shot. The chemistry is close enough that you’ll have a fair chance of getting something with passable exposure.

Once exposed, you have to develop the film. Normally, a Polaroid camera achieves this by squeezing the film sheet out through rollers to release the developer and start the process. Without being able to rely on the camera’s autofeed system, you need to find an alternative way to squeeze out the chemicals and get the image to develop. [Nick] recommends a simple kitchen rolling pin, while noting that you might struggle with some uneven chemical spread across the sheet. Ultimately, it’s a fussy hack, but it does work. It might only be worthwhile if you’ve got lots of Instax film kicking around and no other way to shoot it.

Instant cameras can seem a little arcane, but they’re actually quite simple to understand once you know how they’re built. You can even 3D print one from scratch if you’re so inclined. Video after the break.

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Nostalgic Camera Is A Mashup Of Analog Video Gear

December 18, 2025 by 3 Comments

These days, you get a fantastic camera with the purchase of just about any modern smartphone. [Abe] missed some of the charm of earlier, lower-quality digital cameras, though, and wanted to recreate that experience. The way forward was obvious. He built a nostalgic digital video camera from scratch!

[Abe] figured he could build the entire project around analog gear, and then simply find a way to store the video digitally, thus creating the effect he was looking for. To that end, the build is based around a small analog video camera that’s intended for use with FPV drones. It runs on 5 to 20 volts and outputs a simple composite video signal. This makes it easy to display its output on a small LCD screen, originally intended to be used with an automotive reversing camera. These were both paired with a mini video recorder module from RunCam, which can capture composite video and store it on a microSD card in 640 x 480 resolution.

These parts were quickly lashed together, with the camera sending its output to the RunCam video recorder module, which then passed it on to the screen. Everything worked as expected, so [Abe] moved on to implementing an on-screen display using the MAX7456 chip, which is built specifically for this purpose. It overlays text on the video feed to the screen as commanded by an RP2040 microcontroller. Once that was all working, [Abe] just had to provide a battery power supply and wrap everything up in a nice retro-styled case. Then, at the last minute, the separate camera and recorder modules were replaced by a TurboWing module that combined both into one.

The result is a nifty-looking camera that produces grainy, slurry, old-school digital video. If you love 640 x 480 as a resolution, you’ll dig this. It’s got strong 90s camcorder vibes, and that’s a very good thing.

We love a good custom camera around these parts, especially those that offer deliciously high resolution. If you’re building your own, be sure to let us know. Video after the break.

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