Two men in black shirts stand between a white and a blue exercise bike sitting on a table in front of them. The exercise bikes have black drums slightly larger than a coffee can affixed to the front of the bike which houses the shredding mechanism. In the background is a "Precious Plastics Torino" circular logo.

Getting Shredded Plastic…and Legs

September 23, 2023 by 10 Comments

While electric motors have taken the drudgery out of many tasks, human power has its advantages. [Precious Plastic Torino] has developed a human-powered plastic shredder for those times when an electric motor just won’t do.

Designed primarily for educational purposes at venues where electricity can be difficult to source, but also useful for off-grid environments, this exercise bike-based shredder can take small pieces of plastic and shred them into tiny pieces suitable for use with any of the other machines in the Precious Plastics ecosystem like their injection molding machine. As with all [Precious Plastics] projects, the files are will be open source; however, there is a six month exclusivity period for Patreon subscribers to help fund development efforts.

The build is relatively simple: take an old exercise bike, remove the unnecessary bits, and run the chain up to drive a shredding mechanism mounted on the front of the bike. We think they should’ve kept the flywheel to help keep the momentum going while shredding but can’t fault them for wanting to keep the prototype as simple as possible. Maybe the next step is getting these in spin classes around the country so people can get their exercise and help recycle in their community at the same time!

If this shredder doesn’t suit your fancy, maybe recycle your plastic with SHREDII or this other DIY effort. If you’d rather generate electricity on your exercise bike, then try building this bike generator.

Continue reading “Getting Shredded Plastic…and Legs” →

Decker Is The Cozy Retro Creative Engine You Didn’t Know You Needed

September 22, 2023 by 9 Comments

[John Earnest]’s passion project Decker is creative software with a classic MacOS look (it’s not limited to running on Macs, however) for easily making and sharing interactive documents with sound, images, hypertext, scripted behavior, and more to allow making just about anything in a WYSIWYG manner.

Decker creates decks, which can be thought of as a stack of digital cards that link to one another. Each card in a deck can contain cozy 1-bit art, sound, interactive elements, scripted behavior, and a surprisingly large amount of other features.

Curious? Check out the Decker guided tour to get a peek at just what Decker is capable of. Then download it and prototype an idea, create a presentation, make a game, or just doodle some 1-bit art with nice tools. Continue reading “Decker Is The Cozy Retro Creative Engine You Didn’t Know You Needed” →

Bending Light To Fit Technology

September 22, 2023 by 3 Comments

Solar power is an excellent way of generating electricity, whether that’s for an off-grid home or for the power grid. With no moving parts maintenance is relatively low, and the downsides of burning fuel are eliminated as well. But as much as it’s revolutionized power generation over the last few decades, there’s still some performance gains to be made when it comes to the solar cells themselves. A team at Stanford recently made strides in improving cell efficiency by bending the properties of sunlight itself.

In order to generate electricity directly from sunlight, a photon with a specific amount of energy needs to strike the semiconductor material. Any photons with higher energy will waste some of that energy as heat, and any with lower energy won’t generate electricity. Previous methods to solve this problem involve using something similar to a prism to separate the light out into colors (or energies) that correlate to specific types of cells calibrated specifically for those colors. This method does the opposite: it changes the light itself to an color that fits the semiconductor material. In short, a specialized material converts the energy from two lower-energy photons into a single higher-energy photon, which then strikes the solar panel to create energy.

By adding these color-changing materials as a layer to a photovoltaic solar panel, the panel can generate more energy with a given amount of light than a traditional panel. The major hurdle, as with any research, is whether or not this will be viable when produced at scale, and this shows promise in that regard as well. There are other applications for these materials beyond photovoltaics as well, and the researchers provide an excellent demonstration in 3D printing. By adding these color-change materials to resin, red lasers can be used instead of blue or ultraviolet lasers to cure resin in extremely specific locations, leading to stronger and more accurate prints.

DIY Repair Brings An X-Ray Microscope Back Into Focus

September 22, 2023 by 6 Comments

Aside from idle curiosity, very few of us need to see inside chips and components to diagnose a circuit. But reverse engineering is another story; being able to see what lies beneath the inscrutable epoxy blobs that protect the silicon within is a vital capability, one that might justify the expense involved in procuring an X-ray imager.  But what’s to be done when such an exotic and expensive — not to mention potentially deadly — machine breaks down? Obviously, you fix it yourself!

To be fair, [Shahriar]’s Faxitron MX-20 digital X-ray microscope was only a little wonky. It still generally worked, but just took a while to snap into the kind of sharp focus that he needs to really delve into the guts of a chip. This one problem was more than enough to justify tearing into the machine, but not without first reviewing the essentials of X-ray production — a subject that we’ve given a detailed look, too — to better understand the potential hazards of a DIY repair.

With that out of the way and with the machine completely powered down, [Shahriar] got down to the repair. The engineering of the instrument is pretty impressive, as it should be for something dealing with high voltage, heavy thermal loads, and ionizing radiation. The power supply board was an obvious place to start, since electrostatically focusing an X-ray beam depends on controlling the high voltage on the cathode cup. After confirming the high-voltage module was still working, [Shahriar] homed in on a potential culprit — a DIP reed relay.

Replacing that did the trick, enough so that he was able to image the bad component with the X-ray imager. The images are amazing; you can clearly see the dual magnetic reed switches, and the focus is so sharp you can make out the wire of the coil. There are a couple of other X-ray treats, so make sure you check them out in the video below.

Continue reading “DIY Repair Brings An X-Ray Microscope Back Into Focus” →

That’s Not A Junker… That’s My Generator

September 22, 2023 by 104 Comments

If you live somewhere prone to power outages, you might have thought about buying a generator. The problem is that small generators are cheap but — well — small. Big generators are expensive. [Jake von Slatt] had an idea. He has a “yard car” which we thought might be a junk car but, instead, it is an old car he uses to drive around his yard doing tasks. It has a winch and a welder. Now it has a big generator, too. You can follow the project in the three videos found below.

The project started with a scrap generator with a blown motor. Of course, the car has a motor so — in theory — pretty simple. Remove the generator from the motor and graft it to the car’s motor. But the details are what will kill you.

Continue reading “That’s Not A Junker… That’s My Generator” →

RP2040 Emulator Brings The Voice Of The 80s Back To Life

September 22, 2023 by 24 Comments

You may not have heard, but there’s a chip shortage out there. And it’s not just the fancy new chips that are in short supply; the chips that were fancy and new back when you could still buy them from Radio Shack are getting hard to come by, too. For different reasons, of course, but it does pose a problem that requires a little hacking to fix.

The chip in question here is the General Instrument SP0256, a 1980s-era speech synthesizer chip that [Andrew Menadue] relies on. The LSI chip stored 59 unique allophones, or basic sounds the vocal tract is capable of, and synthesized speech by rapidly concatenating these sounds. The chip and its descendants made regular appearances in computers and games throughout the 80s, so chances are good you’ve heard it. If not, think WarGames (yes, we know that wasn’t actually a computerized voice) or [Stephen Hawking] and you’ll be pretty close.

[Andrew]’s need for such a chip stems from his attempts to give voice to his collection of Psion Organisers, another 80s relic that was one of the first pocket computers. Some time ago he built a speech board for the Psion based on the SP0256-AL2, but had to resort to building an emulator for the chip since none were to be had. The emulator uses an RP2040 and lives on a PCB that has the same footprint as the original chip, so it can just plug right in. He dug up WAV files of the allophones and translated those to sequences of bytes, allowing the RP2040 to output the correct sounds as they’re called for. Speaker problems notwithstanding, it sounds pretty good in the video below.

We’ve featured a fair number of SP0256 projects before, on everything from Amstrad to Z80. We’ve also shown off a few of [Andrew]’s builds before, including this exploration of the voltage tolerance of the RP2040.

Continue reading “RP2040 Emulator Brings The Voice Of The 80s Back To Life” →

Ham Radio Mini Beam

September 22, 2023 by 6 Comments

Years ago, ham radio operators more often than not had land, and usually there weren’t any restrictions on what kind of antenna they could erect on that land. These days you are more likely to live with less or no land, and even if you do own property, you might have restrictions that prevent you from putting up any kind of visible antenna.

But even if that’s not the case, you might not have room for an old-fashioned “tri-bander” or “cubical quad” that the hams of old preferred. [Waters & Stanton] has a 65-year-old design for a miniature beam that he explains, and it produces a good beam antenna in a reduced amount of space. You can watch a video about the antenna below.

The design uses a doublet — a dipole fed with a balanced line and tuned at the feed point. A 22-foot doublet can cover 20 meters down to 10 meters without traps. Adding a director and reflector element provides directionality and gain. A unique arrangement allowed a 12-foot boom to support multiple elements on some bands by introducing a central coil on some elements. For example, the director is tuned to 15 meters using a center coil. But the coil is shorted with a 10 meter quarter stub that acts as a short on that band. You can see a complete explanation in the video.

We were hoping to see a build and some on-the-air testing, but, apparently, that is left as an exercise for the viewer. We imagine that 65 years ago, you’d use a grid dip oscillator to tune the stubs. Today, an antenna analyzer would do the job easily.

Continue reading “Ham Radio Mini Beam” →