Michel Sinner shared with us the start of a series over on 3D Printing For Beginners challenging Clifford Smyth, author of Function Design for 3D Printing, to illustrate in detail a few of the physical properties challenges for design for 3D printing.
…Parts built on an FFF printer are stronger in some directions than others. The directional strength, or anisotropic properties, of objects made using the FFF process superficially resembles the anisotropy, or grain, of wood. It is similar to wood in that there is an axis along which it is weakest and may break more easily, especially in tension. It is different than wood in that this weakness has only one axis, rather than two.
Some of this similarity results for the fibrous construction of both materials. Wood is fibrous due to the nature of the cellulose structures made by its growth and FFF objects are fibrous by virtue of the extrusion process, which extrudes a tiny filament of plastic which is welded together with the other fibers alongside it.
Most wood is strong in compression in all directions, but especially so with the ‘grain’ of the wood, or along the fibers (not the rings) of the structure made by the growth process. Similarly, wood is very strong along the axis of its fibers in tension – so remarkably strong in fact, that it rivals modern exotic composites.
Objects made on an FFF printer have similar properties, but with some important differences. In Compression, FFF parts tend to be strongest along the Z, or layer-wise axis, going up and down as the part sits on the print bed, though this can vary significantly based on finished shape and its internal structure….
…As a designer, it is useful to remember that since the layout of the fibers in each X-Y layer is determined largely by the shape of the object being printed, the designer can easily influence the fiber orientation and the finished strength along these axes by varying the design or printing orientation of the printed piece.
Because of the directional, or anisotropic, strength properties of 3D printed objects it is often useful to break down compound parts into components rather than print them in one piece, in order to make them as strong or easy to print as possible…..
Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!
Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!
The Adafruit Learning System has dozens of great tools to get you well on your way to creating incredible works of engineering, interactive art, and design with your 3D printer! We also offer the LulzBot TAZ – Open source 3D Printer and the Printrbot Simple Metal 3D Printer in our store. If you’ve made a cool project that combines 3D printing and electronics, be sure to let us know, and we’ll feature it here!