We didn’t notice [Nikita]’s post about building a concrete 3D printer, a few months ago, but the idea seems sound: build a basic CNC XY axis and then add a mortar pump and hose to deposit concrete. The video, below, shows the machine in operation.
While it looks interesting, there is essentially no real Z-axis, so this would be limited to some sort of relatively thin forms unless you, perhaps, did a few layers and then further lifted the machine. We also assume wet concrete won’t bridge at all. Still, this might be an interesting project, especially if you have a spare CNC XY axis floating around.
If you buy everything, though, you are looking at an estimated cost of around $7,000 USD. We presume there is enough weight in the concrete that a conventional 3D printer probably isn’t going to cut it. We did wonder, though, if there would be any merit to connecting a conventional plastic-extruding nozzle to be able to lay down support for the concrete.
This might be a good jumping-off point for a more sophisticated machine. In particular, [Nikita] points out that a progressive cavity pump with a variable frequency drive is ideal, because it allows you to vary the extrusion rate and provides a steady flow of concrete. Armed with that knowledge, you could probably figure out the rest pretty easily if you’ve ever built a 3D printer or CNC machine.
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.
[Andrey Rudenko] is building a house in his garage. Not with nails and lumber, but with concrete extruded by his 3D printer. We’ve seen concrete 3D printers in the past, but unlike those projects, [Andrey] isn’t part of a of a university or corporation. He’s just a contractor with a dream. His printer is directly derived from the RepRap project. It’s even commanded by Pronterface.
[Andrey] started with an Arduino Mega 2560 based RepRap RAMPS style controller. His big printer needed big NEMA34 stepper motors, far beyond the current capacity of the stock RAMPS stepper drivers. [Andrey] got in touch with [James] at MassMind who helped him with an open source THB6064AH based driver. [James] even came up with an adaptor cable and PCB which makes the new drivers a drop-in replacement.
Now that his printer was moving, [Andrey] needed a material to print. Concrete chemistry is a science all its own. There are many specialty blends of concrete with specific strength and drying times. Trucking in custom mixtures can get expensive. [Andrey] has come up with his own mixture based on bags of regular concrete mix, sand, and some additives. [Andrey’s] special sauce doesn’t cure especially quickly, but it is viscous enough to print with.
Every piece of [Andrey’s] printer had to be designed and refined, including the nozzle. The concrete printer works somewhat like a frostruder, extruding concrete in 20mm wide by 5mm tall layers. He’s even managed to print overhanging layers and arches exactly like a giant RepRap Mendel.
The printer’s great unveiling will be this summer. [Andrey] plans to print a playhouse sized castle over the course of a week. He’s looking to collaborate with architects, builders, and other like-minded folks. We’d suggest uploading the project to Hackaday.io!