# You wouldn't download a car, would you? How about, 3D print a castle?



## MannDude (Aug 3, 2014)

I want to build a 3D printer in a bad way, but this guy took the open source RepRap software to design a 3D concrete printer, and well... he's printing a damn 'castle'. Read about it here: http://www.ibtimes.co.uk/man-3d-prints-castle-back-garden-using-concrete-printer-he-invented-1459223

Man, this is so neat.


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## rds100 (Aug 4, 2014)

I am not a building expert, but the build quality of this castle looks bad. And with no steel inside the concrete to reinforce it, i wouldn't want to sit inside.


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## vampireJ (Aug 4, 2014)

Obviously that is not sturdy. Likely made from plastics.

I just wonder how much it has costed so far. Probably already very expensive. But that is a nice concept you can do with 3d printer.


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## MartinD (Aug 4, 2014)

No, it's made from concrete.

Edit: Logically, I can't see anything wrong with it in this small form factor. The weight and pressure involved in the 'build' isn't so great as to cause any immediate concern and, if you look closely, you can see that the walls are tied together in the cavity.

All in all... i think it's pretty cool!


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## 5n1p (Aug 4, 2014)

rds100 said:


> I am not a building expert, but the build quality of this castle looks bad. And with no steel inside the concrete to reinforce it, i wouldn't want to sit inside.


you can sit inside, since there is no slab or roof above that walls. While this is all cool and nice, for slabs you would still need some kind of formwork and reinforcement. Not to mention in this structure with only walls, most stresses are compression and it is fine, but when you add slab you will get tension especially over the openings in walls, and with no reinforcement it could collapse. Reinforcement is not there only to take care for tension stresses, but to provide ductility in limit state (moment when structure breaks). Of course you could make prefabricated slab on site and put it on top of that structure, but then its not 3D printed. If you look that houses printed in China they are prefabricated, and have steel truss below the roof. A side from all this I really like this and hope he will post the finished job.


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## HenriqueSousa - WebUp 24/7 (Aug 4, 2014)

Youtube Video

If the method used to build that castle, is the same as the one explained by the guy in the video. In theory the houses should be more resistant than the houses we build at the moment.

But I think this is only being used in countries like Africa, to build entire neighborhoods in a few weeks.


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## 5n1p (Aug 4, 2014)

HenriqueSousa - WebUp 24/7 said:


> Youtube Video
> 
> If the method used to build that castle, is the same as the one explained by the guy in the video. In theory the houses should be more resistant than the houses we build at the moment.
> 
> But I think this is only being used in countries like Africa, to build entire neighborhoods in a few weeks.


Only difference I heard in that video is that he is using reinforcement. But I saw only vertical reinforcement. And in that video he mentioned micro reinforcement (fibers) added to concrete mix which adds to concrete tension bearing capacity. If you watched that video you could see that formwork for slab I have mentioned, its some kind of beams, that he puts on walls and then pour concrete over it. To be honest, while I like this Idea only thing that it could be used for today is the last mentioned in that video, spherical dome like structures, he does not need reinforcement for that, most of the stresses are compression and concrete is great for that. Most critical part of it all is that your machine better not breaks when you start, since if you make big pause in pouring concrete, old and new concrete bond will not hold.


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## HalfEatenPie (Aug 4, 2014)

5n1p said:


> Only difference I heard in that video is that he is using reinforcement. But I saw only vertical reinforcement. And in that video he mentioned micro reinforcement (fibers) added to concrete mix which adds to concrete tension bearing capacity. If you watched that video you could see that formwork for slab I have mentioned, its some kind of beams, that he puts on walls and then pour concrete over it. To be honest, while I like this Idea only thing that it could be used for today is the last mentioned in that video, spherical dome like structures, he does not need reinforcement for that, most of the stresses are compression and concrete is great for that. Most critical part of it all is that your machine better not breaks when you start, since if you make big pause in pouring concrete, old and new concrete bond will not hold.





5n1p said:


> you can sit inside, since there is no slab or roof above that walls. While this is all cool and nice, for slabs you would still need some kind of formwork and reinforcement. Not to mention in this structure with only walls, most stresses are compression and it is fine, but when you add slab you will get tension especially over the openings in walls, and with no reinforcement it could collapse. Reinforcement is not there only to take care for tension stresses, but to provide ductility in limit state (moment when structure breaks). Of course you could make prefabricated slab on site and put it on top of that structure, but then its not 3D printed. If you look that houses printed in China they are prefabricated, and have steel truss below the roof. A side from all this I really like this and hope he will post the finished job.


Civil Engineer here (EIT License)! You're absolutely correct!

From the looks of the picture only forces involved seems to be compression force from the weight of the structure itself. In addition, the arch design in itself is mostly compression forces distributed down each ends (similarly how a dome roof works). Basically, even without reinforcement this structure should be fine!

The only reason concrete is reinforced or pre-stressed is to give it the characteristics of sustaining tension force. Even then the concrete has a pretty good chance of cracking  but this is absolutely normal! Just as long as the cracks aren't too long (you measure it from the base of the crack to the longest "strand") you're fine.

@5n1p explained it really well and clearly. There isn't much more I could add!


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## raindog308 (Aug 4, 2014)

Only one way really to test the build quality...who's up for laying siege with me?


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## HalfEatenPie (Aug 4, 2014)

raindog308 said:


> Only one way really to test the build quality...who's up for laying siege with me?


So... Are we just going to wait it out or are we going to pull a deceptive move?


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## Aldryic C'boas (Aug 4, 2014)

raindog308 said:


> Only one way really to test the build quality...who's up for laying siege with me?


Helmet on, pants down.  Pony battering ram, FULL SPEED AHEAD.


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