If the current Administration of the United States has their way, humans will return to the surface of the Moon far sooner than many had expected. But even if NASA can’t meet the aggressive timeline they’ve been given by the White House, it seems inevitable that there will be fresh boot prints on the lunar surface within the coming decades. Between commercial operators and international competition, we’re seeing the dawn of a New Space Race, with the ultimate goal being the long-term habitation of our nearest celestial neighbor.
But even with modern technology, it won’t be easy, and it certainly won’t be cheap. While commercial companies such as SpaceX have significantly reduced the cost of delivering payloads to the Moon, we’ll still need every advantage to ensure the economical viability of a lunar outpost. One approach is in situ resource utilization, where instead of transporting everything from Earth, locally sourced materials are used wherever possible. This technique would not only be useful on the Moon, but many believe it will be absolutely necessary if we’re to have any chance of sending a human mission to Mars.
One of the most interesting applications of this concept is the creation of a building material from the lunar regolith. Roughly analogous to soil here on Earth, regolith is a powdery substance made up of grains of rock and micrometeoroid fragments, and contains silicon, calcium, and iron. Mixed with water, or in some proposals sulfur, it’s believed the resulting concrete-like material could be used in much the same way it is here on Earth. Building dwellings in-place with this “lunarcrete” would be faster, cheaper, and easier than building a comparable structure on Earth and transporting it to the lunar surface.
Now, thanks to recent research performed aboard the International Space Station, we have a much better idea of what to expect when those first batches of locally-sourced concrete are mixed up on the Moon or Mars. Of course, like most things related to spaceflight, the reality has proved to be a bit more complex than expected.
Today, it can feel like you’re always connected to the grid. We’re constantly alerted to notifications from smart phones, smart watches, and our houses have begun to swell with all manner of internet-enabled devices. [Jake P] wanted a less connected lifestyle, and built a shelf to help realise that goal.
The idea of [Jake]’s Analog Smart Shelf is to serve as a digital check point in his home. It’s a name that more reflects the ethos of the shelf rather than the components. The shelf contains a Qi wireless charging platform, so smartphones can be placed on the shelf when entering the house and left to charge. The shelf also conceals an Amazon Fire tablet behind woodgrain veneer, which displays the time, weather, and basic notification data. This enables [Jake] to see relevant digital information at a glance, while being able to switch off from the online world by simply walking away.
In a lot of fields – motorsport, space exploration, wearables – lighter is better. But it’s not always the case. When you want to damp vibration, stop things moving around, and give things a nice weighty feel, heavier is the way to go. This is the case for things like machine tools, anvils, and yes – speakers. Using this philosophy, [SoundBlab] built a set of concrete speakers. (Youtube link, embedded below)
The concrete speaker enclsosures are sized for 3″ drivers, and were cast using two measuring jugs as the mold. This gave the final product a smooth and glossy surface finish, thanks to the surface of the plastic used. The concrete was also agitated during the casting process to minimise the presence of air bubbles in the mixture.
Once cast, the enclosures are fitted with plywood end caps which mount the Fountek FE85 speaker drivers. These are a full-range driver, meaning no cross-overs or other drivers are required. The speakers are then mounted on stands constructed from wood edging, which are stained in a contrasting colour for a nice aesthetic touch. Felt pads are placed on the base, and polyfill inside the enclosure to further minimise any unwanted vibrations.
This furnace is the work of [Ahmed Ghr], and is as simple a build as they come. The idea is to produce a mold in which to cast concrete to create the furnace. A steel bucket is cut up and used as the outside of the mold, with a pipe inserted in the base to act as a feeder for air and gas. A plastic bucket is then inserted within the steel bucket and held in place with spacers, to create the inner combustion cavity. Concrete is poured in and allowed to set. Once finished, the steel bucket is cut away, and a fire is built over the furnace to melt away the plastic inside. Similar techniques are used to produce the lid, and the furnace is completed.
It’s a build that is executed with the most basic of tools, and should serve as a capable furnace for lower melting point metals at the very least. We’ve seen a lot of cement projects lately, as it turns out. Video after the break.
When designing furniture, material choice has a huge effect on the character and style of the finished product. Wood is a classic option, while more modern designs may use metal, plastic or even cardboard. Less popular, but no less worthy, is concrete. It’s heavy, cheap, and you can easily cast it into a wide variety of forms. [KagedCreations] thought this would be ideal, and whipped up this nifty piece of furniture with an integrated USB hub.
A pair of melamine shelves were scrapped to build the form, in which the concrete table is cast. Melamine is a popular choice, as it’s cheap, readily available, and releases easily from the finished concrete. Along with the USB hub, a wooden board is cast into the base of the concrete table top. This serves as an easy attachment point for the pre-made hairpin-style legs, which can be installed with wood screws.
Some of us are able to get by in life with somewhere between 0 and 1 USB ports. We typically refer to these people as “Mac users”. For the rest of us, too much is never enough, and we find ourselves seeking out expansion cards and hubs and all manner of perverse adapters and dongles. [JackmanWorks] was a man who found himself in need of more connectivity, so he built this beautiful shelf with an integrated 12-port hub.
Material choice is key here, with this build looking resplendent in mahogany and cement. As the core of the build, the USB hub is first disassembled and sealed up to prevent damage from the cement. Hot glue is used to protect the PCB, while electrical tape helps cover the individual ports. The cement is then poured into a form which creates the overarching structure for the shelf, with the USB hub being cast in place. With the cement cured, mahogany boards are then cut and waxed, before installation into the structure. These form the individual shelves which hold phones, hard drives and other USB accessories.
The shelf was designed so that the entire structure is supported through the bottom shelf, which then sits on top of the desktop computer case. It’s an attractive piece, and the weight of the cement construction makes it pleasantly stable in use. It’s rare, but we do occasionally see shelf hacks around these parts. Video after the break.
When starting a new project, the choice of material can have a big effect on the character of the finished product. Wood is stylish and has a certain elegance to it, while polished or brushed aluminium is great for a more futuristic feel. Sometimes though, you just want big, cheap and heavy – in which case, concrete is your friend!
[BALES] was short on USB ports, and needed a hub with plenty of connectivity. Concrete had the benefits of being solid and heavy, and also impervious to beverages. Thus, a melamine form was produced, chosen as its surface doesn’t give the concrete anything to grab on to. A foam skull was cut out and added to create an inlay for decoration, and the 7-port octopus-style hub was placed inside.
With careful attention paid to the mixture consistency, the concrete was poured into the mold and allowed to set. Care was taken to avoid air bubbles and to ensure the mixture flowed completely into the mold, without leaving air pockets behind the inserted components. After allowing it to set for a few days, the part was demolded, with care taken to minimise edge crumbling. The foam skull was removed, and infilled with black epoxy, with a little more used to coat the top and sides of the hub. As a finishing touch, a foam pad was fitted to the base to allow it to sit on a desk without scratching everything up.
In the end, [BALES] has ended up with a hefty hub that won’t skitter around when plugging and unplugging devices. It should also serve admirably as a sturdy drink coaster on those cold winter nights. If you’re trying a similar project yourself, note that sometimes concrete can be surprisingly conductive. Video after the break.