HyPar Gridshell

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.

Print Settings

Printer:

Generic

Rafts: 

No

Supports:

No

Resolution: 

0.2mm

Infill:

20

Filament:

Generic PLA

Notes: 

No special printing settings required. Since the stripes are 1mm in height, one might want to use a layer height of 0.2mm or 0.25mm. The files for the stripes has to be printed twice.

Post-Printing

Assembly

The strips have different lengths. They should be arranged so that the shorter ones sit in the center of the grid and the longer ones on the outside (arranged in descending order). The slots should fit firmly into each other. If they tend to slip out you might want to use some superglue. Increasing the extrusion factor will also help to get a tighter fit.
Push two opposite corners against each other and the double curved shape should appear. Place the HyPar in the stand to preserve the shape.