DIY Trommel Sifts Compost In Style

Composting is a great idea that helps you and the planet at the same time. But all that stuff is going to break down at different rates, and depending on what you put in there and how soon you want to use the compost, you’ll probably have to sift out some unwanted stuff first.

[Minnear Knives] had a bunch of apricot stones in his compost pile, and it was the pits. He did some research and decided to build his own rotary trommel to tumble out the trash. As you will see in the video after the break, it works really well. All he has to do is turn on the motor and shovel raw compost or dirt into one end. Bad stuff tumbles out the other end into a wheelbarrow, while the good stuff is sifted down into a pile under the cylinder. Just look at that rich, fluffy compost.

The best part is that he was able to make it mostly from stuff he had lying around, though he did trade some beer for the v-belt pulley. The cylinder is essentially made from mesh that’s zip-tied to bicycle rims. A 1/4 horsepower motor mounted up top uses that v-belt pulley to spin the cylinder’s rims against casters that are mounted to the frame. Thanks to the pair of bike wheels on the back, he can cart it around the ranch unassisted.

Composting doesn’t have to be any more difficult than a pile in the backyard. But if you don’t have a backyard, why not build a rotating bin that you can monitor from your phone?

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Reducing The Risk Of Flying With Hydrogen Fuels

Flight shaming is the hot new thing where people who take more than a handful of trips on an airplane per year are ridiculed for the environmental impact of their travels. It’s one strategy for making flying more sustainable, but it’s simply not viable for ultimately reducing the carbon impact that the airline industries have on the environment.

Electric planes are an interesting place to look for answers. Though carbon-free long haul travel is possible, it’s not a reality for most situations in which people travel today. Current battery technology can’t get anywhere near the energy density of fossil fuels and larger batteries aren’t an option since every pound matters when designing aircraft.

Even with land travel and electric grids improving in their use of renewables and electric power, aviation tends to be difficult to power with anything other than hydrocarbons. Student engineers in the AeroDelft program in the Netherlands have created Project Phoenix to develop an aircraft powered by a liquid hydrogen fuel cell, producing a primary emission of water vapor. So it is an electric plane, but leverages the energy density of hydrocarbons to get around the battery weight problem.

While the project may seem like an enormous reach peppered with potential safety hazards, redundant safety features are used such as sensors and vents in case of a hydrogen leakage, as well as an electric battery in case of failure. Hydrogen produced three times more energy per unit than kerosene, but is six times the volume in gas form and requires cumbersome compression tanks.

Even though hydrogen fuel only produces water vapor as a byproduct, it can still cause greenhouse effects if it is released too high and creates clouds. The team is exploring storage tanks for slow release of the water vapor at more optimal altitudes. On top of that, most hydrogen is produced using steam methane reforming (SMR), creating up to 150g of greenhouse gases per kWh, and electrolysis tends to be more costly and rarely carbon neutral. Alternatives such as solar power, biofuels, and electric power are looking to make headwind as well, but the technology is still far from perfected.

While it’s difficult to predict the success of the project so early on, the idea of reducing risk in hydrogen fuels may not be limited to a handful of companies for very long.

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The Hornsdale Power Reserve And What It Means For Grid Battery Storage

Renewable energy has long been touted as a major requirement in the fight to stave off the world’s growing climate emergency. Governments have been slow to act, but prices continue to come down and the case for renewables grows stronger by the day.

However, renewables have always struggled around the issue of availability. Solar power only works when the sun is shining, and wind generators only when the wind is blowing. The obvious solution is to create some kind of large, grid-connected battery to store excess energy in off-peak periods, and use it to prop up the grid when renewable outputs are low. These days, that’s actually a viable idea, as South Australia proved in 2017.

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Can You Piezo A Peugeot?

Car manufacturers have a problem when it comes to climate change. Among the variety of sources for extra atmospheric CO2 their products are perhaps those most in the public eye, and consequently their marketing departments are resorting to ever more desperate measures to sanctify them with a green aura. Among these are the French marque Peugeot, whose new electric version of their 208 model features in a slick video alongside a futuristic energy-harvesting billboard.

This is no ordinary billboard, nor is it a conventional wind turbine or solar array, instead it harvests ambient noise in one of the busiest parts of Paris, and turns it into electricity to charge the car with an array of piezoelectric energy capture units. This caught our eye here at Hackaday, because it seemed rather too good to be true. Is it a marketing stunt, or could you make a piezo billboard as a practical green energy device? Let’s take a closer look.

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From Fail To Wail: Guitar Picks Made From 3D Printed Waste

Between failed prints and iterative designs that need a few attempts before you nail them down, a certain amount of wasted material is essentially unavoidable when 3D printing. The good news is that PLA is a bioplastic and can be broken down via industrial composting, but even still, any method that allows you to reuse this material at home is worth taking a look at.

In a recent video, [Noah Zeck] details one potential use for your scrap plastic by turning his failed 3D prints into guitar picks. The idea here could really be applied to anything you can make out of thin plastic sheeting, but the fact that you can easily and cheaply produce picks with a commercially available punch makes this application particularly appealing.

The first step in this process is about as low-tech as it gets: wrap your scrap printed parts in rags, and beat them with a sledge hammer. This breaks them up into smaller and more manageable pieces, which is important for the next step. If the parts are small enough and you’ve got a decently powerful blender you don’t mind devoting to plastic recycling, we imagine that would make short work of this step as well.

Once suitably pulverized, [Noah] puts the plastic on a piece of glass and gets it warmed up with a heat gun. PLA has a fairly low glass transition temperature, so it shouldn’t take much time to soften. Then he puts a second piece of glass on top and squeezes them together to get a thin, flat sheet of plastic. Once cooled, he punches his guitar picks out of the sheet, with bonus points if the colors swirled around into interesting patterns. If you’re not musically inclined, we’ve seen a very similar method used to produce colorful floor tiles.

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Learn Water Purification Techniques With This STEM Learning Kit

We see a lot of great STEM education projects. These projects have a way of turning into something much larger. How many commercial devices and machines are built on Raspberry Pi’s and Arduinos? [Ryan Beltrán] is using common materials to teach people how to clean water. This particular kit demonstrates a water purification process called electro-coagulation.

When current is passed through two electrodes suspended in water it changes the surface charge on the suspended solids. This causes the solids, metals, and oils to clump together which makes them considerably easier to treat and clean.

The kit consists of a jar, electrodes, some 3D printed parts, and a pre-flashed Arduino. There’s also salts and filters to finalize the purification process. Students can start the experiment right away and if they’re inspired they’ll have all the tools to try more advanced techniques.

Often STEM kits lean heavily to robotics or computer science, but there are so many vast and interesting fields out there with problems that need to be solved.

Brussels Looks Towards Banning Fossil Fuel Transportation As Soon As 2035

Many cities around the world routinely struggle with smog. Apart from being unsightly, heavy air pollution has serious negative health effects, both in the short term and with regards to long-term life expectancy. Over the years, governments have tried to tackle the problem with varied tactics around the world.

When talking about smog, Brussels is not one of the cities that comes first to mind. Regardless, the local government has developed its new climate plan that seeks to abolish fossil fuel vehicles from its streets by 2035. The scheme has a variety of measures that will be staggered over the coming years. It’s part of a broadening trend in transportation, and something we’ll likely see more of around the world in coming years.

What’s The Go?

Brussels is in the process of reducing congestion by converting former roads into pedestrian-only spaces. REUTERS/Eric Vidal

Under the new plan, diesel vehicles will be banned from the city’s Low Emission Zone, or LEZ, by 2030. This will further extend to gasoline vehicles in 2035. Furthermore, special categories of higher polluting vehicles will have bans enforced even earlier. Motorcycles had previously been exempt from the LEZ, but moving forward, the most polluting models will be locked out of the city centre as soon as 2022. The aim is to reduce emissions, with a goal of cutting CO2 output by 40 percent by 2030, and becoming carbon neutral by 2050. The city is also exploring the concept of a Zero Emission Zone, or ZEZ, expanding upon earlier efforts which transformed the Boulevard Anspach from a heavily-trafficked road into a pedestrian-only plaza. Continue reading “Brussels Looks Towards Banning Fossil Fuel Transportation As Soon As 2035”