Since January, I have had the pleasure and privilege to work for the artist Sarah Oppenheimer, aiding her in the process of realizing a number of installation pieces. Sarah hired me to apply Grasshopper to a number of problems in the process of preparing her pieces for fabrication, from initial conception and design all the way to the production of detailed fabrication documents. She and her Studio Director Uri Wegman were already using Rhino to develop her designs, so it was a natural jump to Grasshopper to add to their capacities and automate a range of processes.

The first project for Sarah that I worked on in January is currently being fabricated at Kunstbetrieb Basel, where we are lucky to work with a team of extremely talented engineers. Now that the project is nearing completion, I wanted to share a little bit about the process and the ways I’ve been applying Grasshopper on this project.

Prior to my involvement, Sarah had realized a version of the piece at the VonBartha Garage in Switzerland. This version was skinned with wood veneer panels.

The goal was to fabricate a new version of the piece, but this time out of aluminum sheet. Sarah and Uri had developed a clever system of perforating sheets to facilitate folding them into complex forms.

However, with this method, each crease could only be folded so far. This required a re-modeling of the piece geometry in order to ensure that each crease was under the maximum fold angle. For this purpose I made a GH definition that color coded every edge based on the number of additional facets necessary to “smooth out” the crease in question. This visual feedback made the process of reshaping the piece much faster, allowing us to create a number of variations and quickly test their feasibility.

The next constraint to tackle was the available aluminum sheet size we had to work with. Due to the size of the piece, the skin had to be broken up into a number of smaller pieces that would then be wrapped around a frame. To facilitate this process, I developed a definition that “sliced” the piece along user-specified planes, unfolded each resulting segment, and tested for fit within our limited sheet size.

Up until this point, the models we were working with were polysurfaces without thickness. Having settled on a scheme by which to subdivide the piece, the next major definition handled a detailed, rigid unfolding of each segment, with material thickness taken into account. This directly gave us the necessary channel widths to be milled into the piece for a given fold angle.

Finally, I developed a definition to process the results from this unfolding and automatically generate the curves to drive the CNC mill for the sheet perforations.

It is thrilling for a student of architecture and parametric design to see a project finally make it off the screen and become actual. The photos below show various stages of the pieces being fabricated. Images courtesy of Sarah Oppenheimer, Kunstbetrieb and Galerie Von Bartha.

The ribbed structural frame

Beginning to assemble the skin

The bottom piece

The top piece

The tip of the top piece

Seam and Crease Details

As my work with Sarah on this and other pieces continues I will post more updates!