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.