The concrete printer looks interesting.

The concrete printer looks interesting.

Sure does. Hopefully they will use it for good and not profit.

@Jeremiah_Wood Thanks for your comment, but clearly you can’t fathom the potential benefit a technology like this could have on the third world, or anywhere (for that matter) where there is insufficient affordable housing. As I actually took the time and looked into this, I also know that contour crafting have patented the fuck out of this technology meaning that anyone wishing to produce an open source and cheap equivalent to this will have to work so much harder and still likely run up against litigation if they can’t prove prior art. Consequently, my hope is these guys make it an accessible technology that can be used to the benefit of the many many people that do not have a home, as opposed to leveraging it to make 1st world building firms richer.

@Mic_Possert yeah, the gist of the Tedx talk seemed pretty positive but it seems the research and subsequent IP was done under the banner of USC and I assume they hold the patents. Universities (in my experience) are often motivated by financial gain before social well being. Hence my concern that its not used to its full potential for the greater good. Of course I understand USC need a means of recouping costs. I’d have thought an open gpl would have served the same purpose as a patent here if their intent was entirely benevolent.

@Jeremiah_Wood yeah I think I can fathom that. I can also fathom that my original statement was not a slogan, it was a (highly truncated) synopsis of a considered opinion. So, yeah, nice work there. Oh and ‘corporations are bad’ is a slogan btw.

@Mic_Possert valid point and I’m aware of that but I can’t reverse engineer their designs and then publish my findings eh? I ask because, for it to be accessible it needs to be well documented. Your hyperthetical Bolivians would likely only find the tech useful if it had been broken down to simple and readily sourced components and used open sourced electronics. From what i can tell, the really innovative bit of their IP is the concrete extruder and the materials science. Scaling a reprap to the size where you could cover 10’s meters is quite feasible by the look of it and is certainly already covered by numerous GPLs.

I’d like to see your write ups if you’re prepared to link them.

I wouldn’t worry too much about patents being filed for additive manufacturing now. So much stuff is happening that novelty is going to be extremely hard to prove when any of these patents are brought up.

Plus, there are a ton of ways to apply 3d printing to buildings, and actually printing the concrete is pretty fiddly option.

My personal favorite is something I saw in the MIT media lab: They had a robotic arm with an expanding foam sprayer mounted on the end, and they were printing forms for concrete. It used replaceable $1 mixing nozzles and very little feed material, plus the whole toolhead weighed about a pound. You could easily put one on a very light weight motion system for building a house.

Contour crafting on the other hand has a massive tool head and an even more massive hose pumping concrete up to it. The cost of transporting whatever motion system they use would destroy any benefits from their tech.

@Nick_Parker I’m not sure I’m convinced that there are better methods to build a house using an automated system, aside form the one you mentioned what other options are there?
I disagree that transport costs would prohibit the Contour crafting solution, The tool head is probably no bigger or heavier than a concrete mixer and compared to the usual apparatus and manpower required to construct an equivalent structure using tilt slab, timber, brick etc I can’t see it being a barrier. That’s an informed opinion btw as I’ve spent a lot of time on construction sites over the years, from international airport terminals to residential housing projects. I already know about the guys in the UK using a CNC router and plywood sheet to build houses -which is very cool but requires a lot of man power still.

@Mic_Possert Hah! Bloody unreliable anarchists :). Maybe you should email the NSA - they probably have a copy cached somewhere.

@Tim_Rastall I obviously don’t know as much about construction as you, but I’m thinking about the weight of whatever motion system they use to wave the toolhead around, not the actual cement extruder.

A regular cartesian gantry would be huge and need to be assembled on site, and I suspect a robotic arm would involve pretty massive torques at house sizes which would make accurate positioning a real trick. The backlash caused by a concrete hose can’t be fun.

@Nick_Parker Those are all good points but I’ve been thinking about this one a lot and had a few conversations with some folks on the forums and it looks quite feasible to use stage lighting truss (which is light and extremely strong/rigid) to build a square gantry and then have a ‘H’ bot style truss that moves in the Y axis with a the toolhead attached to a carriage moving a long the X axis. Linear motion can be achieved with rack and pinion or maybe even core xy (using high tensile rope and pulleys). Weight of the toolhead and resulting backlash only become a problem if you are moving it around with high acceleration rates and the extrusion speed will likely prohibit high speeds anyway. If you look at eh contour crafting tool head, you’ll also see it has some independent rotational movement capability that would reduce the need for lots of jerky infill movement.
Z movement can be achieved by a number of means, belts/chains even scissor lifts.

@Tim_Rastall Yeah I suppose cartesians wouldn’t be too huge of a trouble for domestic jobs. Bringing the gantry on a truck would probably be cheaper than hiring a bunch of people to build forms and such. However if we’re talking about the third world, nobody’s shipping anything like this tech around.

One last point I just thought of: The concrete for Contour Crafting probably needs to be a pretty precise consistency, which would be very hard in the middle of nowhere.

@Nick_Parker Agreed but if you make it simple enough from a framing perspective, you could utilise steel beams or even timber as a support structure and then aluminium channel and rollers/wheels as a linear guide that sits on top of the supports. I’m not suggesting it’s a perfectly formed concept but it show significant promise and if you can put say, $10-30K? into a bot that spits out houses at a rate of 1 every few days, that’s a compelling investment for a suitably inclined charity or whatever. The concrete question is an interesting one but there has in fact been a fair bit or work already done in this area - for instance, adding shredded nylon plastic bags improves the working consistency, cure time and tensile strength of concrete.