There’s nothing more pleasing on a hot day than an ice-cold beverage. While the vast majority of us have a fridge in the kitchen, sometimes it’s desirable to have a further fridge in the lab, games room, or workshop. To that end, you may find value in this ultra-cheap, low-cost DIY fridge build from [Handy_Bear].
Like many tiny fridge builds, this design eschews complex gas-cycle refrigeration techniques for simple Peltier modules. These are devices that have one cold side and one hot side, because they move heat when electricity is applied. This build uses a Peltier module fitted with a fan to better shift away heat from the hot side, improving the module’s cooling ability.
The “fridge” itself is assembled out of thick XPS insulation foam. A hot wire cutter was used to cut several slabs which were then assembled using hot glue. The Peltier module is installed on the back, at the top of the fridge. Thus, air which is cooled in this area will then travel down through the rest of the fridge’s cavity. [Handy_Bear] also goes over how to produce a working hinge and a gasket for the door, which helps with ease-of-use and efficiency. As a nice touch, a set of 12V LED lights are also installed inside, which light when the door is open. Just like the real thing!
The final build is noisy, slow to cool down, and it uses 60 watts of power to cool down just two regulation-sized sodas. Notably, you could fit two standard NATO smoke grenades in the same space, as they’re almost-identically sized (ask us how we know). However, smoke grenades don’t usually need to be refrigerated.
None of that means it isn’t fun though! Plus, [Handy_Bear] notes that adding a second Peltier would greatly aid the fridge’s ability to quickly chill your
grenades sodas. You might even like to explore the use of special fan designs to make the fridge even quieter! Video after the break.
Continue reading “DIY Mini Fridge Is Pure Brilliance In Foam” →
[CarrotIndustries] wanted to add an audible warning for when the refrigerator door was left open. The result is a fridge buzzer that attaches to the inside of a fridge door and starts buzzing if the door is left ajar for too long.
The main components of the fridge buzzer consist of an MSP430G2232 low-power MCU connected to a SI7201 hall sensor switch, along with a CR2032 battery holder, push button and buzzer. The MSP430’s sleep mode is used here, consuming less than 3 µA of current which [CarrotIndustries] estimates lasting 9 years on a 235 mAh CR2032 battery.
A 3D printed housing is created so that the board slides into a flat bed, which can then be glued onto to the fridge door. The other mechanical component consists of a cylinder with a slot dug out for a magnet, where the cylinder sits in a mounting ring that’s affixed to the side of the fridge wall that the end of the door closes on. The cylinder can be finely positioned so that when the refrigerator is closed, the magnet sits right over the hall sensor of the board, allowing for sensitivity that can detect even a partial close of the fridge door.
All source code is available on [CarrotIndustries] GitHub page, including the Horizon EDA schematics and board files, the Solvespace mechanical files, and source code for the MSP430. We’ve featured an IoT fridge alarm in the past but [CarrotIndustries]’ addition is a nice, self contained, alternative.
We see a ton of clock projects around these parts, and being hackers, we love to feature them all. But every once in a while we stumble upon a great new way to display the time that really gets our attention and requires a closer look, such as this moving fridge magnet clock.
The fridge magnets [Craig Colvin] built this unique clock around are the colorful plastic kinds that have adorned the lower regions of refrigerators in toddler-filled households for ages. Instead of residing on a fridge, [Craig] laminated a sheet of white acrylic to a thin sheet of steel, to give the magnets something to hold onto. Moving the numbers is the job of a CoreXY-style mechanism. The belt-driven Cartesian movement maneuvers a head to to the right location to pick up a number; a servo in the head moves two powerful magnets into position under the number. The head then moves the number to the right spot, releases its magnets, and the number stays put on the board. You can see it in action in the video after the break.
While we love this as it is, it brings to mind some great mods. One can imagine the addition of letters to make a legit word clock, or to just add a calendar display. We’d also love to see these magnets in their natural habitat by building this into the door of a working fridge.
Continue reading “Moving Fridge Magnets Make For Unique Clock” →
We love writing about DRM here at Hackaday. Because when we do, it usually means someone found a way to circumvent the forced restrictions laid upon by a vendor, limiting the use of a device we thought is ours once we bought it. The device in question this time: the water filter built into GE’s fridges that would normally allow its “owner” to pour a refreshing glass of cold water. Except the filter is equipped with an RFID tag and an expiration, which will eventually deny you that little luxury. And if that’s already a feature, you can bet it won’t just let you insert any arbitrary filter as replacement either.
Enraged by every single aspect of that, [Anonymous] made a website to vent the frustration, and ended up tearing the culprit apart and circumvent the problem, with a little help from someone who was in the same situation before. As it turns out, the fridge comes with a “bypass filter” that is just a piece of plastic to fit in place of the actual filter, to pour unfiltered, but still cold water. That bypass filter is also equipped with an RFID tag, so the reader will recognize it as a special-case filter, which luckily enough doesn’t have an expiration counter.
The general idea is to take out that bypass filter’s RFID tag and place it on a generic, way cheaper filter to trick the fridge into thinking it simply doesn’t have a filter in the first place, while still enjoying the filters actual functionality. However, this might not be the most stable solution if the tag isn’t placed in the exact position. Also, retrieving the tag in the first place proved tricky, and [Anonymous] initially ended up with nothing but the antenna pad, while the tag itself remained sturdily glued into the plastic piece.
Continue reading “Defeating Fridge DRM With Duct Tape And A Dremel” →
Air compressors are often loud, raucous machines – but they don’t have to be. [Eric Strebel] built a remarkably quiet compressor using parts salvaged from an old fridge. After several years of use, it was due for an upgrade (Youtube link, embedded below}.
While performance of the original setup was good, [Eric] desired a compressor with more capacity for his resin casting activities. A 15 gallon air tank was sourced from a damaged Craftsman brand compressor, and pressed into service. The build involved plenty of sheet metal work to mount the various components, as well as an upgrade to the pressure regulator.
During the refit, [Eric] takes the time to answer questions from the audience about his original build. He notes that the fridge compressor has worked well without using any noticeable amount of oil, and that there was a problem with water build up in the original tank which has been solved in the new rig.
It’s a great example of building your own tools, which can provide years of service if done right. Check out our write up on [Eric]’s first build, or his work on photogrammetry. Video after the break.
Continue reading “Air Compressor From Fridge Parts Gets An Upgrade” →
Freezers are highly useful devices. You can preserve food, stop a dead animal from stinking out your apartment, and keep your vodka at the optimal drinking temperature. Of course, most of us bought ours from the local whitegoods store, but [Tech Ingredients] set out to build his own (YouTube, embedded below).
Unlike your freezer at home, this build doesn’t use the typical heat pump and refrigeration cycle with a compressor and expansion valve and so on. Instead, this freezer uses thermoelectric devices to pump heat, in combination with a glycol cooling circuit and fan-cooled radiators.
It’s not the most efficient or practical way to build a freezer, but it is functional and the device demonstrably works, making ice cubes over the course of a few hours. Performance can be further improved by moving the radiator assembly outdoors to make the most of the low ambient temperatures.
[Tech Ingredients] has further plans to experiment with a dessicant-based refrigeration system, and reports that initial results are promising. We’re eager to see how that goes; we’re fans of any rig that can cool a beer down in no time flat. Video after the break.
Continue reading “Build Your Own Freezer With Thermoelectric Coolers” →
There’s nothing like a true hack, where something useful is concocted from bits of scrap and bargain store finds. Builds like these are much more than the sum of their parts, especially when they result in a useful tool, like this DIY vacuum chamber that’s good for all sorts of jobs.
Everything [Black Beard Projects] used to accomplish this build is readily available almost everywhere in the world, although we have to note that appliance recycling efforts and refrigerant recovery programs have made it somewhat harder to lay hands on things like the old fridge compressor used here. The big steel cooking pot is an easy thrift store find, though, and while [Black Beard] used high-quality stainless fittings and valves to plumb the chamber, pretty much any cheap fittings will do.
The one sketchy area of the build is the plexiglass sheet used for the chamber top, which seems a little on the thin side to us. You can see it flexing in the video below as vacuum is pulled; it survived, but we can see it failing catastrophically at some point. We stand ready to be reassured in the comments. Still, it’s a tidy build with a few nice details, like wiring a switch into the old start capacitor box and using car door edge protector as a gasket on the chamber.
Fridge compressor hacks are standard fare, of course, being used to make everything from air compressors to two-stroke engines. Sometimes they’re even used to keep things cool too.
Continue reading “Hacked Vacuum Chamber Won’t Suck A Hole In Your Budget” →