A lot is said about 3D printing and how it may change (or not) the world. As an architect I will try to show you how it can change the way you think about physical models of your designs. After more than ten years of use of Blender for building virtual buildings (that sometimes are build in real life after 😀 ), to be able to print those designs right on my desktop is realy exciting. So here are some examples of how 3D printers can be used for architectural projects, and some practical aspect of 3D printing with FDM for architectural designs.
Several technologies exist for 3D printing, but the most widely used is Fused Deposition Modelling (FDM), thanks mainly to the RepRap project. An extruder heat a filament and deposit it layer by layer to create the shape. The material is generaly PLA (a biodegradable plastic) or ABS. Some technics allow much higher quality, wider range of material and color printing, and you can use the services of some websites to have your projects printed at some cost. But here I will speak of the FDM, the only technic that one can buy for himself. One can build its own 3D printer for around 500$ or even less, or buy a kit or a complete 3D printer for less than 2000$. The different models have different speed, reliability and precision.
At Chantier Libre, the FabLab I’m lauching we bought an Ultimaker, as it is known to be very fast and accurate, and to be useable easily without too much tinkering. But the main reason is that it is OpenHardware.

The thing I prefer with 3D printing is that it allows you to create shapes you could not build with traditionnal technics. As an example I used for that again a softbody simulation to generate the geometry, and a decimate modifier to make a polygonised “low-poly” version of it. It is inspired by the work of Gaudi:

[Show as slideshow]

After modelling in Blender, you export the model in STL format, and open it in CURA, the software that will change this model to something understandable by the printer. In Cura you can resize, move and rotate your model, and then slice it: it will calculate each layer of material that will be deposited by the printer. You can choose the speed, the temperature, the thickness of the walls, the density of the fillings…

A timelapse of the whole process:

For simple forms, the quality is good with the default settings of the software, no need for hours of experimentations. You have to cope with the typical FDM surface : you can see the layers of PLA (but with high quality settings, and a layer height of 85 micrometers, it’s not so much a problem). You can after that sand the model like in the example below, or use some new filaments that leave a sandstone like surface (I’m testing it right now):

For more complex forms like the ones in the video, you may need to add supports (the software places them for you) for the hangover. In some cases, you may need to adjust the settings (like for the columns of the example) to prevent some small blobs or wires. And like every tool, the more you know it, the bertter you use it. For such complex models, the use of the 3D print tool box included in Blender really can help you out sparing a lot of time .

The most annoying part is the time needed to print. A small objects of less than 3cm can be printed in less than 10 minutes, like the ones below:

But a big object like the example takes easily 20 hours to print. Don’t forget we work in 3D: 3 times larger means 27 times longer. So you can easily understand you are not so much limited my the size of the printer (it can print 20cmx20cmx20cm) but by the time.

I may say to finish that today, with a reasonably preiced printer you can achieve some very nice results, and it allows you to design shapes you could not imagine build before. But don’t forget this technology is still young : it takes some time, it’s not perfect, and the printer itself will give its best result only if you spend time to master it. And thats why FabLabs are so great: the fab managers master the tools for you and help you get the best of your 3D models.

Here you can download the .blend file:
cathedrale

Or directly the two stl files to print them:
cathedrale
cathedralefacettes