Many decades ago, a much younger version of me was in the car with my dad and my brother, cruising down the highway on some errand or another. We were probably all in the front seat, and none of us were wearing seatbelts; those were simpler times. As we passed under an overpass, my dad said, “Do you know why the overpasses on these roads are so high?” Six-year-old me certainly didn’t, but it was clear dad did and had something to say about it, so we just shook our heads and waited for the lesson. “Because that’s how big nuclear missiles are.” He then went into an explanation of how the Interstate Highway System in the USA, then still in its infancy, was designed to make sure the armed forces could move around the country, so overpasses needed to allow trucks with big loads to pass.
It was an interesting lesson at the time, and over the years I’ve continued to be impressed with the foresight and engineering that went into the Interstate system here in the US. It’s far from perfect, of course, and it’s only recently that the specifications for the system have started to put a pinch on things that seem totally unrelated to overpass dimensions — namely, the size and efficiency of wind turbines.
After two years of dreaming, designing, and doing, [Andrey Rudenko] has finally finished 3D printing his concrete castle. We’re sure a few readers will race to the comments to criticize the use of “castle” as an acceptable descriptor, but they’d be missing the point. It’s been only three months since he was testing the thing out in his garage, and now there’s a beautiful, freestanding structure in his yard, custom-printed.
There are no action shots of the printer setup as it lays down fat beads of concrete, only close-ups of the nozzle, but the castle was printed on-site outdoors. It wasn’t, however, printed in one piece. [Andrey] churned out the turrets separately and attached them later. He won’t be doing that again, though, because moving them in place was quite the burden. On his webpage, [Andrey] shares some insight in a wrap-up of the construction process. After much experimentation, he settled on a layer height of 10mm with a 30mm width for best results. He also discovered that he could print much more than his original estimation of 50cm of vertical height a day (fearing the lower layers would buckle).
With the castle a success, [Andrey] plans to expand his website to include a “posting wall for new ideas and findings.” We’re not sure whether that statement suggests that he would provide open-source access to everything or just feature updates of his future projects.
We hope the former. You can check out its current format as the Architecture Forum, where he explains some of the construction capabilities and tricks used to build the castle.
His next project, a full-scale livable structure, will attempt to print 24/7 (weather permitting) rather than the stop-start routine used for the castle, which turned out to be the culprit behind imperfections in the print. He’ll have to hurry, though. [Andrey] lives in Minnesota, and the climate will soon cause construction to take a 6-month hiatus until warm weather returns. Be sure to check out his website for more photos and a retrospective on the castle project, as well as contact information—[Andrey] is reaching out to interested parties with the appropriate skills (and investors) who may want to help with the new project.