Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4923704.

HyPar gridshell through active bending.

The geometry of the HyPar gridshell is generated by inscribed modulation of junction slots. The fabrication process produces flat PLA stripes. During assembly they have to be elastically bent in order to fit into place. Imperfections, the assembly process itself and the stored potential energy lead to torsion of the stripes. The result is a state of lower potential energy, where the inscribed geometry is restored partially.

At first the HyPar is modelled traditionally as ruled surface. The second step involves Kangaroo 3D (live physics engine inside Rhino & Grasshopper) to find a solution for the fabrication. Each strip is defined as a rod and all of the knots are fed into a co-planar group. The resulting system line of every strip is then used to generate the final individual geometries.

A small stand is included to keep the HyPar in shape. The size is ~17x17cm, but it can be scaled to any size. Note that the bending behaviour might change with the thickness of the stripes.