Authors: Davis Wing
Mentors: Larry Howell
Insitution: Brigham Young University
Origami-based mechanisms provide the opportunity for constructing highly compact systems for deployment in space and other applications. One pattern that shows great promise in this field is the flasher pattern, which unfurls a flat, rotationally symmetric arrangement of panels from a cylindrical spiral. The fold pattern is complex, and in attempting to better understand how it can be made from non-zero-thickness materials, and desiring a model which could be easily 3D printed, the following research was developed.
As a result of this research, a flasher model was constructed which folds out to a deployed state that has almost triple the projected area of the stowed state. The idealized flasher was designed using Tessellatica, a program developed by Dr. Robert Lang. Turning the two-dimensional output from Tessellatica into a structure suitable for 3D printing required beginning with the stowed form of the flasher and thickening it across all panels. Fold lines were preserved at zero-thickness to ensure correct kinematics, and the bottom face of the model was constrained to be flat. Initial attempts at fulfilling these design requirements made apparent the need for more constraints, such as constraining the thicknesses of different panel sections to be proportional to their distance from the center and ensuring that the final unfolded state involved no overhangs.
The final step in designing the model involved the implementation of living hinges. In a 3D printed design, living hinges offer mobility without assembly at the cost of being potential failure points, depending on print line orientations. Any hinge built from paths running in line with that hinge would immediately fail upon bending. The solution to this problem of parallelism was to use two layers with 0.1mm thickness on the bottom of the model, at 90° angles to one another. This allowed for all of the hinges, regardless of orientation, to be able to have the strength necessary to form a workable part.
This research advances the manufacturability of zero-thickness origami patterns by providing models capable of being conveniently manufactured by anyone with a 3D printer. Specifically, it demonstrates a method for developing a zero-thickness model into a foldable structure of non-negligible thickness, and how to use default 3D slicer settings to build robust living hinges. The models have been uploaded on two popular file-sharing websites, Thingiverse and Printables, and have been downloaded hundreds of times.