Normally, a 3D printer that under extrudes is a bad thing. However, MIT has figured out a way to deliberately mix full extrusions with under extruded layers to print structures that behave more like cloth than normal 3D printed items. The mesh-like structure apparently doesn’t require any modification to a normal 3D printer, just different software to create special code sequences to create the material.
Called DefeXtiles, [Jack Forman] is producing sheets and complex structures that appear woven. The process is known as “blob-stretch” because of the way the plastic makes blobs connected by fine filaments of plastic.
According to the talk by [Jack] (see the second video, below), the technique works with different types of filament and it is possible to print very large items folded up, even on a standard printer. After printing, you simply unfold or unwrap the plastic. For example, by printing a spiral, a 70 meter roll of “fabric” came out of an unremarkable-looking 3D printer. The thickness is under 0.4 mm.
Another example is the full-sized skirts you can see in the paper. They print in a roll form and then expand after printing. Other demonstration objects include a shuttlecock (you know, the thing you use for badminton) and lampshades.
We were hoping to find software or G-code files to demonstrate the technique, but if they were there we missed them. However, it seems like it should be easy enough to create some test files. Let us know if you try.