Aalto University - ARTS 3D Printing

3d Scanning

3D scanners are able to reconstruct a digital geometry of a physical model. Although there are specialized scanners that can create highly accurate and detailed digital versions of objects, currently there are mobile applications available that allow you to use a smartphone to create quick-and-easy to use models. Depending on the level of accuracy and the specific needs of each project it is possible then to use one of these three options:

• Photogrametry: A process that uses pictures taken from different angles of an object to estimate the three-dimensional coordinates of points in its surface. It is possible to do this with a mobile phone or a digital camera. Usually this process works better for medium size objects.

• Handheld Scanner: This machine allows you to generate 3D mesh data by using infrared light and a camera. It is possible to scan all sizes of objects (from a shoe to a car). That is the reason why it is used heavily in sculpture. The machine could be held on a tripod static while using a turntable to scan the object, or it can be manipulated by hand. This type of scanner can also scan color data. On the downside, transparent or glossy objects, as well as hair are not easily scanned.
• We have a Handheld scanner at the university’s FabLab (Otakaari 7). You can book a time to use the machine HERE

Designing in CAD software

Most of the projects that artists, designers and architects develop will fall into this category. For 3D printing, it is possible to use any of the CAD software’s available. Whether it is Rhino 3D, Archicad, SolidWorks, Fusion 360 or even Maya.

Despite the great freedom that this means, it is important to remember that anything can be modeled on a 3D software, but not everything can be 3D printed. What does this mean? It means that it is important to consider how your design is modeled, and how will it be printed. Let’s review a couple of key ideas that will help with the design process.

•  Designs should be watertight: Your model needs to have a volume. The technical name for this is manifold. This means the surface on your 3D design should be connected in all edges. In rhino, make sure that your model reads as a closed polysurface on the properties menu. Non-manifold 3D objects cannot be printed, or they usually fail by missing parts of their geometry when exporting. This is especially frequent in 3D animation files.
• Keep track of units: When exported, most of the mesh files will be formatted to millimeters (mm). If you are doing a scale model, it is important to scale your model in your CAD modeling program before exporting.
• Design for reality: Keep in mind that 3D printers cannot deposit material on thin air. Depending on the technology you will use for printing, support structures can be added automatically later on when converting your model to a code. Nevertheless, it is a good practice to avoid using support structures when possible, because it will affect the quality of the surface and it will require some post processing work.

If you wish to learn more about how to design for each specific technology, please review the following articles:

3D Hubs - How to design for FDM printing _{(external link)}

3D Hubs - How to design for SLA printing _{(external link)}

3D Hubs - How to design for Material Jetting printing _{(external link)}