Pulp-Molding: A Use For Cardboard Confetti

November 5, 2021 by Kristina Panos 21 Comments

We’re pretty sure that we don’t have to tell you how great cardboard is. You probably sing the praises yourself and use it for everything from a work surface protective layer to a prototype of your next amazing build. But if you still find yourself flush with cardboard even after all that, here’s one thing you can do with all those pieces that are too small to use for anything else– chuck them in an old blender, whip up some cardboard pulp, and press that gunk into some 3D-printed molds.

In addition to a step-by-step of the process, [flowalistik] offers a mold set of STL files for various useful items like a pencil holder, a box with a lid, a tray, and a coaster, as well as the Fusion 360 files in case you want to change them around. You might want to seal the coaster with something protective so that it doesn’t mold/disintegrate/bloom from condensation.

Each part consists of the walls, the wall clip that keeps them closed, but allows for de-molding and reuse, the bottom lid, and the top lid. All these prints need to be pretty high-res so that they can withstand the pressure of the clamp holding it all together. [flowalistik] recommends a layer height no larger than .03mm and a 20% infill.

The process of making the pulp itself is fairly simple, and the recipe only calls for water and some kind of binder. To start, remove all tape, coatings, staples, and anything else non-soluble from the cardboard. Cut it into bite-sized pieces your blender will enjoy, and add water and PVA glue or rice paste. Mix it up, remove the excess water by squeezing your pulp inside of a piece of cloth, and then use it to fill up your mold. You’ll want to press out the water as you go and fill it further, then finally apply the clamp. You can start de-molding parts on a schedule, starting with the clamp after about six hours. Once it’s fully dried in about two days, you can treat it like MDF and sand, cut, or even drill it. We think some of these would look pretty good with a coat of paint.

Need your objects to be more sturdy? Keep that printer warmed up — you can use prints to cast concrete, too.

The Metabolizer Is Turning Trash Into Treasure Even Faster Now

November 5, 2021 by Kristina Panos 5 Comments

Do you remember [Sam Smith]’s Metabolizer from a few years back? In case you’ve forgotten, this baby takes trash and turns it into printed plastic objects, and it’s solar-powered to boot. Although the Metabolizer didn’t win the 2018 Hackaday Prize, [Sam] and his machine won many achievements that year, including the Open Hardware Challenge. It’s fantastic to see the project still improving.

To recap, the sun hits the solar panels and charge up the battery bank. Once there’s enough power to start the reaction, it gets dumped into a heating element that turns biomass into biochar. This smoke is cooled, collected, refined, and fed into a small gas generator, which produces DC power to run a 3/4-horsepower shredder and the trash printer.

[Sam] likens this beast to a Rube Goldberg machine in that it performs an overly-complicated chain reaction to do a simple task. We certainly see his point, but we think that this machine is worth so much more than those classic machines, which tend to do nothing useful at all and tend to consume many resources in the process. On the contrary, the Metabolizer’s chain reaction starts with sunshine and ends with useful objects that keep plastic out of landfills. Honestly, it’s more akin to a compost heap with a PhD in Biology and a handful of steroids and a 3D printer attached.

Unfortunately, [Sam] couldn’t get a prototype working in time for the Prize, and he turned to Patreon to gain support after the $1,000 ran out. Three years and a ton of improvements later, [Sam] has a working prototype that’s cheaper, more efficient, and easier to build. But can it be built relatively easily by someone other than [Sam]? Consider the gauntlet thrown down.

Not happy with your standard-style compost pile? You need a DIY trommel to sift out the bad stuff.

Prepare For Wildfire Season With An Air Quality Monitor

November 4, 2021 by Bryan Cockfield 12 Comments

For some reason, wildfire seasons in Australia, North America, and other places around the world seem to happen more and more frequently and with greater and greater fervor. Living in these areas requires special precautions, even for those who live far away from the fires. If you’re not sure if the wildfires are impacting your area or not, one of the tools you can build on your own is an air quality meter like [Costas Vav] shows us in this latest build.

The air quality indicator is based around an Adafruit Feather RP2040 which is in turn based on the 32-bit Cortex M0+ dual core processor. This makes for a quite capable processor in a small package, and helps accomplish one of the design goals of a rapid startup time. Another design goal was to use off-the-shelf components so that anyone could easily build one for themselves, so while the Feather is easily obtained the PMS5003 PM2.5 air quality sensor needed to be as well. From there, all of the components are wrapped up in an easily-printed enclosure and given a small (and also readily-available) OLED screen.

[Costas Vav] has made all of the files needed to build one of these available, from the bill of materials to the software running on the Pi-compatible board to the case designs. It’s a valuable piece of technology to have around even if you don’t live in fire-prone areas. Not only can wildfire smoke travel across entire continents but simple household activities such as cooking (especially with natural gas or propane) can decimate indoor air quality. You can see that for yourself with an army of ESP32-based air quality sensors.

Soil Sensor Shows Flip-Dots Aren’t Just For Signs

October 28, 2021 by Donald Papp 13 Comments

Soil sensors are handy things, but while sensing moisture is what they do, how they handle that data is what makes them useful. Ensuring usefulness is what led [Maakbaas] to design and create an ESP32-based soil moisture sensor with wireless connectivity, deep sleep, data logging, and the ability to indicate that the host plant needs watering both visually, and with a push notification to a mobile phone.

A small flip-dot indicator makes a nifty one-dot display that requires no power when idle.

The visual notification part is pretty nifty, because [Maakbaas] uses a small flip-dot indicator made by Alfa-Zeta. This electromechanical indicator works by using two small coils to flip a colored disk between red or green. It uses no power when idle, which is a useful feature for a device that spends most of its time in a power-saving deep sleep. When all is well the indicator is green, but when the plant needs water, the indicator flips to red.

The sensor itself wakes itself up once per hour to take a sensor measurement, which it then stores in a local buffer for uploading to a database every 24 measurements. This reduces the number of times the device needs to power up and connect via WiFi, but if the sensor ever determines that the plant requires water, that gets handled immediately.

The sensor looks great, and a 3D-printed enclosure helps keep it clean while giving the device a bit of personality. Interested in rolling your own sensor? The project also has a page on Hackaday.io and we’ve previously covered in-depth details about how these devices work. Whether you are designing your own solution or using existing hardware, just remember to stay away from cheap probes that aren’t worth their weight in potting soil.

Being Green, It’s A Rich Man’s Game

October 26, 2021 by Jenny List 245 Comments

It’s an old saying with an apocryphal origin: “May you live in interesting times“. We Brits are certainly living in interesting times at the moment, as a perfect storm of the pandemic, rising energy prices, global supply chain issues, and arguably the post-Brexit departure of EU-national truck drivers has given us shortages of everything from fresh vegetables in the supermarket to carbon dioxide for the food industry. Of particular concern is a shortage of automotive fuels at the filling station, and amid sometimes-aggressive queues for the pumps it’s reported that there’s a record uptick in Brits searching online for information about electric cars.

Nothing Like A Crisis To Make You Green

My VW Polo loaded for EMF 2018 — How I miss my little car, here loaded for EMF 2018.

This sudden interest in lower-carbon motoring may be driven by the queues rather than a concern for the planet, but it’s certainly true that as a culture we should be making this move if we are to have a hope of reducing our CO2 production and meeting our climate goals. A whole slew of lifestyle changes will have to be made over the coming years of which our car choices are only a part. Back to those beleaguered Brits again, a series of environmental protests have caused major disruption on the motorway network round London, not protesting against the traffic but campaigning for better home insulation.

For reasons of personal circumstance rather than principle, earlier this year I gave my trusty VW Polo to an old-Volks-nut friend and now rely on a bicycle. Living where I do within reach of everything I need it hasn’t been as challenging as I expected it to be, and aside from saving a bit of cash I know my general fitness level has gone up. Though I have less need for a car now than I used to, I intend to find myself another vehicle in due course so that I can do silly things such as throwing a Hackaday village in the back and driving halfway across Europe to a hacker camp. With an awareness that whatever I choose should be as good for the planet as I can make it then, I’ve been cruising the used-car websites to see what I can find.

Continue reading “Being Green, It’s A Rich Man’s Game” →

Going Forward To The Land: Technology For Permaculture

October 21, 2021 by Jenny List 34 Comments

It’s usual for a Hackaday scribe to read hundreds of web pages over a typical week as we traverse the world in search of the good stuff to bring you. Sometimes they’re obvious Hackaday stories but as you’ll all no doubt understand we often end up on wild tangents learning about stuff we never expected to be excited about. Thus it was last week that I happened upon a GQ piece charting the dwindling remains of the communes set up in rural California by hippies during the counterculture years.

With only a few ageing residents who truly embraced the back-to-the-land dream remaining, these adventurously-designed home-made houses are gently decaying into the forest. It’s a disappearing world, but it’s also close to home for me as someone who crew up on a self-sufficiency smallholding in the 1970s. My parents may not have been hippies in the way those of everyone else in that scene at the time seemed to be, but I learned all my curiosity and hacking skills in the many opportunities presented to a small child by an unruly combination of small farm and metalworking business. There’s part of me that would build a hippy home in a Californian forest in a heartbeat, and throw myself with gusto into subsistence vegetable growing to get me through each winter.

Continue reading “Going Forward To The Land: Technology For Permaculture” →

Turning Old Masks Into 3D Printer Filament

October 19, 2021 by Tom Nardi 23 Comments

Disposable masks have been a necessity during the COVID-19 pandemic, but for all the good they’ve done, their disposal represents a monumental ecological challenge that has largely been ignored in favor of more immediate concerns. What exactly are we supposed to do with the hundreds of billions of masks that are used once or twice and then thrown away?

If the research being conducted at the University of Bristol’s Design and Manufacturing Futures Lab is any indication, at least some of those masks might get a second chance at life as a 3D printed object. Noting that the ubiquitous blue disposable mask is made up largely of polypropylene and not paper as most of us would assume, the team set out to determine if they could process the masks in such a way that they would end up with a filament that could be run through a standard 3D printer. While there’s still some fine tuning to be done, the results so far are exceptionally impressive; especially as it seems the technique is well within the means of the hobbyist.

The first step in the process, beyond removing the elastic ear straps and any metal strip that might be in the nose, is to heat a stack of masks between two pieces of non-stick paper with a conventional iron. This causes the masks to melt together, and turn into a solid mass that’s much easier to work with. These congealed masks were then put through a consumer-grade blender to produce the fine polypropylene granules that’re suitable for extrusion.

Mounted vertically, the open source Filastruder takes a hopper-full of polypropylene and extrudes it into a 1.75 mm filament. Or at least, that’s the idea. The team notes that the first test run of filament only had an average diameter of 1.5 mm, so they’re modifying the nozzle and developing a more powerful feed mechanism to get closer to the goal diameter. Even still, by cranking up the extrusion multiplier in the slicing software, the team was able to successfully print objects using the thin polypropylene filament.

This is only-during-a-pandemic recycling, and we’re very excited to see this concept developed further. The team notes that the extrusion temperature of 260 °C (500 °F) is far beyond what’s necessary to kill the COVID-19 virus, though if you planned on attempting this with used masks, we’d imagine they would need to be washed regardless. If the hacker and maker community were able to use their 3D printers to churn out personal protective equipment (PPE) in the early days of the pandemic, it seems only fitting that some of it could now be ground up and printed into something new.