2022 Hackaday Prize: Make Your World More Disaster Resistant, More Engaged

July 25, 2022 by 10 Comments

Following along with the 2022 Hackaday Prize theme on building a better world by doing what we all do best – hacking together solutions – the fourth round of the Prize focuses on making our local communities more resilient against and sensitive to severe weather and environmental disasters. Whether it’s an early warning system for wildfires or a distributed communication network that will keep working even when the cell phone service goes down, we’re challenging you to help make your world safer by reacting sooner and better. Get your project entered now!

Sensing

We love systems that help us monitor our environments, and not just for idle curiosity or citizen science. Sometimes it’s critical. We’ve seen monitors aimed at giving you a personal particulate air quality indicator, especially helpful for people with respiratory problems when downstream of a forest fire.

But even better is networking these together to generate an air quality map, or to log long-run trends over time and space. CanAirIO, for instance, has both a fixed and mobile unit that can help map out CO2 and particulate matter quality. Or maybe it’s not wildfires that invade your airspace, but rather pollution from car use. We’ve seen projects like that before too, and anything along these lines would make a great entry into this challenge round. Could you predict local air quality? Continue reading “2022 Hackaday Prize: Make Your World More Disaster Resistant, More Engaged” →

50-Year-Old 8-Track Changer Repair And Hack

July 25, 2022 by 28 Comments

For reasons still unclear, [Techmoan] has procured an RCA 8-track changer that holds five tape cartridges in a custom carrier. It somewhat works, but had a bit of mechanical issues here and there which needed some maintenance. Additionally, the player is designed for the US market and 60 Hz mains, but [Techmoan] is in the UK with 50 Hz.

Although electronics are used for the basic tape player portion, everything else is operated by mechanical gears, levers, and motors. The system plays both sides of each tape cartridge through to completion, and then switches automatically to the next one in the stack. Cartridges could be up to 90 minutes each, making for over seven hours of playing time. Oddly, the system does not repeat automatically after the fifth tape ends –operator intervention is required. It’s not entirely clear whether these carousels were primarily intended to play background music inside businesses, or built for niche consumer applications.

After discovering there was no setting to adjust the tape’s speed for 50/60 Hz operation, [Techmoan] could have ordered or fabricated a larger-diameter pulley for the motor drive shaft. But in true hacker style, he instead solves the problem with cellophane packing tape. By trial and error, he builds up the pulley diameter by winding lengths of tape until the music sounds just “good enough” to his ear. Then he pulls out the wow and flutter meter to really zero in — and gets it bang on. He says that this changer is needed for a future video, so we’re looking forward to see how it will be employed.

If you like these old mechanical logic controls, check out the video below the break. If you want dig into the workings of an 8-track player, check out Jenny List’s retro teardown from 2017.  Does anyone still use 8-track tapes any more?

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How Does The James Webb Telescope Phone Home?

July 25, 2022 by 31 Comments

When it comes to an engineering marvel like the James Webb Space Telescope, the technology involved is so specialized that there’s precious little the average person can truly relate to. We’re talking about an infrared observatory that cost $10 billion to build and operates at a temperature of 50 K (−223 °C; −370 °F), 1.5 million kilometers (930,000 mi) from Earth — you wouldn’t exactly expect it to share any parts with your run-of-the-mill laptop.

But it would be a lot easier for the public to understand if it did. So it’s really no surprise that this week we saw several tech sites running headlines about the “tiny solid state drive” inside the James Webb Space Telescope. They marveled at the observatory’s ability to deliver such incredible images with only 68 gigabytes of onboard storage, a figure below what you’d expect to see on a mid-tier smartphone these days. Focusing on the solid state drive (SSD) and its relatively meager capacity gave these articles a touchstone that was easy to grasp by a mainstream audience. Even if it was a flawed comparison, readers came away with a fun fact for the water cooler — “My computer’s got a bigger drive than the James Webb.”

Of course, we know that NASA didn’t hit up eBay for an outdated Samsung EVO SSD to slap into their next-generation space observatory. The reality is that the solid state drive, known officially as the Solid State Recorder (SSR), was custom built to meet the exact requirements of the JWST’s mission; just like every other component on the spacecraft. Likewise, its somewhat unusual 68 GB capacity isn’t just some arbitrary number, it was precisely calculated given the needs of the scientific instruments onboard.

With so much buzz about the James Webb Space Telescope’s storage capacity, or lack thereof, in the news, it seemed like an excellent time to dive a bit deeper into this particular subsystem of the observatory. How is the SSR utilized, how did engineers land on that specific capacity, and how does its design compare to previous space telescopes such as the Hubble?

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Custom Raspberry Pi Case Shows The Whole Workflow

July 25, 2022 by 29 Comments

If you are a process junkie and love seeing the end-to-end of how a thing is made and with what tools, then watch [Michael Klements] show off his Raspberry Pi case design. His case has quite a few cool-looking elements to it, and incorporates 3D printing as well as laser-cut and clear bent acrylic for a gorgeous three-quarter view.

[Michael]’s write-up (and accompanying video, embedded below) are partly a review of his Creality 3D printer, and partly a showcase of his Raspberry Pi case design (for which he sells the design files for a small fee on his Etsy store.) But the great part is seeing the creation of every piece that goes into the end product. Not everyone is familiar with the way these tools work, or what they can create, so it’s nice to see attention paid to that side of things.

Both the blog post and the video nicely show off what goes into every part. The video opens with unpacking and setting up the 3D printer (skip ahead to 4:58 if you aren’t interested), followed by printing the parts, laser-cutting the acrylic on a K40 laser cutter, bending the acrylic using a small hand tool, and finally, assembling everything. For the curious, there are also links to the exact parts and equipment he uses.

Like we said, it’s part 3D printer review and part showcase of a design he sells, but it’s great to see each of the parts get created, watch the tools get used, and see the results come together in the final product. And should you wish to go in the opposite direction? A one-piece minimalist case for your Raspberry Pi is only a 3D printer away.

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A Tiny Forest Of Resistors Makes For Quick And Dirty Adaptive Optics

July 25, 2022 by 16 Comments

The term “adaptive optics” sounds like something that should be really complicated and really expensive. And in general, the ability to control the properties of optical elements is sufficiently difficult enough that it’s reserved for big-science stuff like billion-dollar space telescopes.

But that doesn’t mean there aren’t quick and dirty adaptive optics that are suitable for the budget-minded experimenter, like this thermally deformable mirror. As [Zachary Tong] explains, this project, which started quite some time ago, is dead simple — a 4 by 4 array of through-hole resistors stand on end, and these are attached to a glass coverslip that has been aluminized on one side. An Arduino and a couple of shift registers make it possible to individually address each of the 16 resistors in the array. Passing a current through a resistor heats it up a bit, leading to thermal expansion and a slight deflection of the mirror sitting on top of the array. Controlling which resistors heat up and by how much should lead to deformation of the mirror surface in a predictable way.

The video below shows some of [Zach]’s experiments with the setup. Unfortunately, he wasn’t able to fully demonstrate its potential — the low-quality mirror didn’t cooperate with his homebrew interferometer. He was, however, able to use a dial indicator to show deflection of the mirror in the 2- to 3-micron range by heating the array. That alone is pretty cool, especially given the dirt cheap nature of the build.

As for practical uses, don’t get too excited. As [Zach] points out, thermal systems like this will probably never be as fast as MEMS or piezoelectric actuators, and many use cases for adaptive optics really don’t react well to added heat. But changing the shape of a mirror with air pressure is another thing.

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Complex Movements From Simple Inflatables, Thanks To Physics

July 24, 2022 by 5 Comments

Inflatable actuators that change shape based on injected pressure can be strong, but their big limitation is that they always deform in the same way.

The Kresling pattern, which inspired the actuator design.

But by taking structural inspiration from origami, researchers created 3D-printed actuators that show it is possible to get complex movements from actuators fed by only a single source of pressure. How is this done? By making the actuators physically bi-stable, in a way that doesn’t require additional sources of pressure.

The key is a modified design based on the Kresling pattern, with each actuator having a specially-designed section (the colored triangles in the image above) that are designed to pop out under a certain amount of positive pressure, and remain stable after it has done so. This section holds its shape until a certain amount of negative pressure is applied, and the section pops back in.

Whether or not this section is popped out changes the actuator’s shape, therefore changing the way it deforms. This makes a simple actuator bi-stable and capable of different movements, using only a single pressure source. Stack up a bunch of these actuators, and with careful pressure control, complex movements become possible. See it in action in two short videos, embedded just below the page break.

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Automated Hotend Swapping For Less Wasteful Multicolor Printing

July 24, 2022 by 16 Comments

Multicolor printing on FDM machines can be tricky to get working flawlessly, and purging hotends when changing colors can end up wasting a lot of filament and material. To solve this problem for the popular Prusa i3 and Ender 3 printers, [BigBrain3D] developed the Swapper3D, an automated system that swaps the entire hotend when the material is changed, eliminating the need for purging almost entirely. Video after the break.

The Swapper3D works very similarly to the tool-changing systems on CNC machines, and is just as satisfying to watch. A large circular carousel on the side of the machine holds up to 25 hotends, and in practice, a pair of robotic arms pop out the previous hotend, cut the filament, and load up the specified hotend from the carousel. This means you can have a separate hotend for each color or type of filament. Since most existing hotends also integrate the heating element, [BigBrain3D] created a special hotend assembly that can be robotically removed/inserted into the heater block.

The Swapper3D is designed to be used with existing filament changers like the Prusa MMU and the Mosaic Palette. Using these systems involves a lot of purging, to the point where you sometimes end up using more filament during purging than you need for the actual part. On one five-color demo print, the Swapper3D reduced the print time by 45% and the filament used by a massive 86%. It also helps to eliminate problems like stringing and color fading in multicolor prints. With those advantages, it looks like the Swapper3D might be a worthwhile upgrade if you do a lot of multi-color printing, even though it adds quite a bit of complexity to the printer.

For larger, more expensive machines, swapping the entire toolhead is becoming more popular, with even E3D stepping into the fray.

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