Via
In Minnesota, contractor
Andrey Rudenko
is currently working on a project of gargantuan proportions that seems
to be stretching and exploring the limits of 3D printing technology.
Using a printer that was substantially modified and expanded, he has
printed a concrete castle in his own backyard. And at 3 by 5 meters,
this concrete structure is the world's first 3D printed concrete castle,
and one of the largest objects that has, up till now, ever printed with
3D printing technology.
Rather than trying to build a machine that caters to theme parks and
history enthusiasts, this project grew out of a desire to construct a 3D
printer capable of constructing durable, realistic and inhabitable
houses. He's already looking at various locations to realize this: "last
winter in Minnesota, which was long and frigid, showed that it is
crucial to have multiple areas in different countries for experimental
printing since you can never predict which conditions will arise."
But Rudenko, who has a background in engineering and
architecture, chose to firstly print his fantastical castle. This allows
its creator to search for and experiment with the limits and
possibilities this machine offers to construction companies. The
castle's unique features and shapes offers many challenging
opportunities to do this, and leave room for Rudenko to make minor
adjustments to the machine. And of course, it's also a wonderful
showpiece for his huge 3D printer.
As Rudenko told 3ders.org, this project follows years of preparation and planning:
"I've been interested in this technology since I was in my
teens. My concrete printing experiments started about 20 years ago, but
at that point, advanced computers and software were not available for
this type of technology. It wasn't until a couple years ago that I came
across the RepRap project and started working on this machine again. It
took about a year to build and develop special concrete mixes.
Additional inspiration came from the naturally-laid layered sandstone I
saw on a trip to Arizona a few years back. Ideally, I hope I can obtain
the same natural look to my printed walls."



Furthermore, progress was also hampered because of the
finances involved. Rudenko therefore ended up financing the printer
independently, which led to many creative engineering solutions.
"When I was starting out, potential sponsors were
wary of providing funds since they did not think the technology would go
this far. Once the castle structure is built and the capabilities of
the printer are evident, I plan to conduct an auction of the ownership
to the first house; since this will be the first functional 3D printed
house ever built, I'm hoping there will be a lot of takers and this will
become a valuable landmark."
A project of this size obviously needs a printer of corresponding
proportions, and Rudenko necessarily built his own machine. While he has
received lots of very helpful feedback from the RepRap community, the
actual construction was of his own design. This massive machine is
driven by Arduino Mega 2560 board and software, which is not too
different from some other 3D printers, but it requires special stepper
drivers "For a big printer, I need special drivers that can handle the
heavy weight of the machine as well as be compatible with the
software/firmware. The best fit I found was from James Newton's Mass
Mind."
'These drivers ended up being the only ones to work properly
with Marlin Firmware (I sampled other drivers, which failed), and were
powerful enough to move such a huge printer.' Rudenko added.


This printer is therefore slightly different than the one developed by Behrokh Khoshnevis
at USC. "Design-wise, I'm creating a natural, free-layering of fine
concrete and my goal is to have a nice-looking, natural texture, without
the need for any additional finish, similar to rammed earth
technology.' Rudenko is also seeking to develop a portable machine that
even smaller construction companies can afford. 'The final price will be
known once we build a few houses, but to the best of my knowledge, I
currently see it as being priced at $30,000-50,000, though this will
also vary depending on the parts and type of model."
When that time comes, Rudenko hopes to be able to deliver a
number of different kits that individual customers and small companies
can put together themselves. "Obviously I can't ship the whole machine,
but I can ship an extruder, control box, some major parts, etc to help
individuals put together their own version." Khoshnevis's printer, on
the other hand, at least appears to be heavier and larger, and Rudenko
expects that only large-scale construction companies will be able to
afford it.
The building process of this 3D printed concrete castle is now complete,
but it's also a learning process for Rudenko's future plans. He's
currently printing approximately a layering of 50 centimeters per day,
though the size and width of the layers vary throughout the
construction. Regular layering is being printed at 30mm width by 10mm
height, but Rudenko can print layers of virtually any size. "For special
areas like crown moldings, I am reducing the height to 5 mm; I'm also
reducing speed in delicate arias."
Of course, a construction of this size requires the right materials to sustain the sheer size and weight of the concrete.
Rudenko said, "Layering cement was an extremely difficult task-
it required extensive tuning of the printer on a programming level, as
well as using exact quantities for the cement mix. While testing the
printer, I ran into obstacles (such as the nightmare of the extruder
clogging) and discovered even further abilities of the printer, like
that it can print much more than 50cm a day as I originally thought."
Rudenko therefore resorted to including rebars in the bottom
and top walls. 'They are needed during the pouring of a variety of
cementitious filling materials inside the printed walls." The cement
used, however, is just a regular cement mix with a few additives. 'It is
possible to use a special quick-setting concrete to speed up the
process, but it will affect the cost, and I don't see much reason to
build a house extremely fast at the expense of higher cost and lower
quality."
Instead, Rudenko is after quality and new possibilities. "The more
important advances of this technology lie in its architectural
possibilities and energy-efficiency. Architects have waited many years
for this technology, and now that it's here, this opens up a whole
window of possibilities; soon, we will see new kinds of architecture
used to construct new structures."
This Minnesotan constructor is seeking to a part of
this: "I plan to concentrate on the development of further 3D printing
technology in construction and building a community/network of people
worldwide interested in research and development of this technology,
with the possibility of providing DYI kits as well as a full line of
model construction printers."
For now, however, printers that are suitable to construct homes and be
commercially viable as well are still in the distant future. But Rudenko
is optimistic about the possibilities for both his device as well as
this industry. "My current standard is 10 millimeters in height by 30
millimeters in width, but countless other options are available with
just the click of a button." he said.
Rudenko is in the process of redesigning the printer based on the
lessons learned. His goal will be to have an upgraded printer that
prints 24 hours a day until the project is finished.
"I'm also planning to print the structure in one piece;
printing the castle turrets by themselves was a bad idea as they were
extremely difficult to lift and place. Additionally, I've figured out
how to print a roof; the only thing is that the material I'd print with
would have to be used in warmer climates for now."
Rudenko's next project is a real full-scale livable house. "The
amount of correspondence I am getting proves high demand and interest in
this new technology. I want to make sure that for the next project, I
have the right team doing the job to fully use all of the benefits of
the 3D printing machine."
"I am open to offers from individuals or companies interested
in owning the first house of this type built with the newest 3D printing
technology and ready to provide abundant funds to completely cover the
project and all its expenses. The interested party needs to own the
lot/site and possess a permit for a house built by 3D Printing
technology." Rudenko would also like to collaborate with the interested
architects, designers, and software engineers experienced in 3D tools.
And you can contact him via this email for further questions.
It has been two years since Rudenko first began toying with the idea
of a 3D printer that was capable of constructing homes. 'I have
previously been sure I could print homes, but having finished the
castle, I now have proof that the technology is ready.' Rudenko said.
"The current prototype I am working on at the moment is just a
small part of the line of printers I am designing. We are talking about
the beginning of a new era in construction industry. There is still much
to be done."
Watch a video of Andrey Rudenko's printing process here:
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