An L-shaped orange mounting structure with two white reservoirs on top, a set of pumps on the outer bottom edges, and a membrane cell bolted together in the center. The parts are connected by a series of transparent tubes.

Open Source Residential Energy Storage

Battery news typically covers the latest, greatest laboratory or industry breakthroughs to push modern devices further and faster. Could you build your own flow battery stationary storage for home-built solar and wind rigs though?

Based on the concept of appropriate technology, the system from the Flow Battery Research Collective will be easy to construct, easy to maintain, and safe to operate in a residential environment. Current experiments are focusing on Zn/I chemistry, but other aqueous chemistries could be used in the future. Instead of an ion exchange membrane, the battery uses readily attainable photo paper and is already showing similar order of magnitude performance to lab-developed cells.

Any components that aren’t off-the-shelf have been designed in FreeCAD. While they can be 3D printed, the researchers have found traditional milling yields better results which isn’t too surprising when you need something water-tight. More work is needed, but it is promising work toward a practical, DIY-able energy storage solution.

If you’re looking to build your own open source wind turbine or solar cells to charge up a home battery system, then we’ve got you covered. You can also break the chains of the power grid with off-the-shelf parts.

A black device with a monochrome LCD sits on a wooden table. It's keyboard extends below the frame. On the screen is the "Level 29" BBS service login.

Internet Appliance To Portable Terminal

Few processors have found themselves in so many different devices as the venerable Z80. While it isn’t powerful by modern standards, you can still use devices like this Cidco MailStation as a terminal.

The MailStation was originally designed as an email machine for people who weren’t onboard with this whole computer fad, keeping things simple with just an adjustable monchrome LCD, a keyboard, and a few basic applications. [Joshua Stein] developed a terminal application, msTERM, for the MailStation thanks to work previously done on decoding this device and the wealth of documentation for Z80 assembly.

While [Stein] designed his program to access BBSes, we wonder if it might be a good way to do some distraction-free writing. If that wasn’t enough, he also designed the WiFiStation dongle which lets you communicate over a network without all that tedious mucking about with parallel ports.

If you’d like something designed specifically for writing, how about an AlphaSmart? Wanting to build your own Z80-based project? Why not start with an Altoids-sized Z80 SBC, but don’t wait forever since Z80 production finally ended in June.

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A black guitar with red rings on its body is held by a man in a black shirt. Text pointing to the red ring of guitar picks says, "This spins."

1000 Picks Make For A Weird Guitar

String instruments have a long history in civilization, helping humans make more complex and beautiful music. We wonder what our forebears would think of this guitar strummed with 1000 picks?

[Mattias Krantz] wondered what the best number of picks was to play guitar and took the experiment to its illogical extreme. Starting with zero picks and working up through various 3D printed multi-picks he tests all the feasible combinations of handheld picks.

After that, he switches gears to a fishing rod-actuated system of several picks in a ring. Not pleased with the initial acoustics of the picks in this system, he switched to printing his picks in a more flexible filament to better approximate the characteristics of the human thumb. Finally, he takes us to the undiscovered country of a spinning ring of 1000 picks strumming the underside of the strings and the… interesting acoustic result. As many pointed out in the comments, this blurs the line between a guitar and a hurdy gurdy.

If you want more melodic musical mischief, perhaps try this optical guitar pickup, a $30 guitar build, or get fancy with a 3D printed violin?

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A rough cut piece of wood sits on a workbench. A light and a tumbleweed are mounted on top so that the light shines through the tumbleweed. A woman in a ball cap and white tank top is crouched in the background smiling.

Cisco Ball Is The Tumbleweed Opposite Of A Disco Ball

Inspiration can strike a maker at any moment. For [Laura Kampf], it happened in the desert when she saw a tumbleweed.

Tumbleweeds roll through the western United States, hitting cars on the interstate and providing some background motion for westerns. [Kampf] found the plant’s intricate, prickly structure mesmerizing, and decided to turn it into a piece of contemplative kinetic art.

[Kampf] attached the tumbleweed to a piece of wood using epoxy and mounted it to what appears to be a worm drive motor nestled inside an interestingly-shaped piece of wood. As the tumbleweed turns, a light shines through it to project a changing shadow on the wall to “create silence, it creates calmness, it takes away from the noise that surrounds it.” While [Kampf] has some work to do to get the sculpture to its finished state, we can get behind her mantra, “The most important thing about the phase of execution is to get started.”

Are you looking for some projects of your own to help you find calm? How about some ambient lighting, a sand drawing table, or a music player that keeps things simple?

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Bright green shelving units suspended with silver hardware from a black frame. They are against a dark wooden wall.

Sliding Shelves Supersize Storage

Organizing things in your home or workshop is a constant battle for some of us. Until we have access to a Tardis or bag of holding, maybe the next best thing is a sliding shelf system.

[HAXMAN] found a great set of sliding shelves online, but after recovering from sticker shock decided he could build something similar for much less. The frame for the shelving was built from 4×4 posts, some 2x4s, and strut channel track welded to steel 2x6s. Aluminum plates bolted to strut trolleys support the weight of the shelving units he built from plywood.

Everything was painted with a multi-material paint formulated for covering both wood and metal so everything has a uniform appearance. We love the bright shelving offset by the more classic black appearance of the rack. Just because its storage, doesn’t mean it has to look boring!

Looking for more clever storage solutions? You might like your to make your own shadow boards, favor Gridfinity, or just wonder what other readers do to organize their electronic odds and ends.
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A circular concrete pond in a garden. A small round fountain jets water out in the center and a solar panel and control box are visible attached to the end of the pond opposite the camera. On the top left is the text, "3D printed, Solar powered, and Arduino controlled" in yellow

Solar Fountain Aerates Garden Pond

Sometimes off-the-shelf solutions to a problem don’t meet your expectations. That’s what led [TomGoff] to build his own solar pond fountain.

This build features a lot of creative reuse of materials [TomGoff] already had on hand, like the end of a cable reel for the platform and a wheelbarrow inner tube for flotation. A 3D printed nozzle in the center of this apparatus is attached to a 12 V water pump and the whole thing is controlled by an Arduino running 30 seconds on and 3 minutes off to conserve battery power.

A hand-built perfboard contains a light dependent resistor (LDR) to tell the Arduino not to run at night, the relay for the pump, and a battery charge monitor. Be sure to check out the full write-up to see the video of the Tinkercad electronics simulation as well as the code. A 20 W solar panel keeps the whole thing charged so you don’t have to run mains power out to your pond.

If you need more solar projects for your garden, how about this Charmander lamp or a solar powered irrigation system?

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An odd looking apparatus for cleaning floppy disks. A neon green disk tray is suspended on metal linear rails in a vertical orientation. It can move back and forth through a set of cleaning heads and a set of drying fans. There are some control buttons on the font as well as a string of addressable LEDs and two speakers.

Rube Goldberg Floppy Disk Cleaner

Floppies were once the standard method of information exchange, but decades of storage can render them unreadable, especially if mold sets in. [Rob Smith] wanted to clean some floppies in style and made a Disco Rube Goldberg-Style device for the job.

Starting with a disk caddy on linear rails, [Smith] has a track for the floppy to follow. First it goes through a set of pads with cleaning solution on them, and is then dried off with heating elements. To make it more fun, the device has LEDs and a set of speakers at the bottom to treat the disk to a more complete car wash-esque experience.

Cotton swabs and a cleaning solution are all you really need to do the job by hand, but if you have a lot of floppies, that can get tedious quickly. [Smith] compares his machine’s performance to doing it by hand with both IPA and a dish soap solution showing that his machine does indeed clean the disks and usually makes them more readable than they were before. He cautions that it might be best to make multiple copies of the disk during the cleaning process as it isn’t always constructive though.

Thinking about archiving that stack of floppies under your workbench? While Linux doesn’t support the drives anymore, we’ve covered a couple different methods in the past and the importance of reading the flux.

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