Owner: San Francisco Museum of Modern Art
Size: 235,000 SF
Date: 2016 (estimated completion)
Fabricator: Kreysler & Associates
Size: 84,045 SF
The complex three-dimensional geometry of the rippled façade, which will be the signature architectural feature of the museum’s new building, relies on digital fabrication to produce 700 façade panels. Each façade panel has its own unique mold geometry with complex double curvature. Kreysler & Associates utilizes CNC machinery to mill EPS foam molds in the precise geometrical shape of the rippled façade panels.
The fabrication process begins with a CNC Hotwire machine to control a heated wire that melts a path through raw blocks of EPS foam. The Hotwire is a 4-axis CNC machine making rough cuts approximately one inch above the final mold surface. Grasshopper scripts for Rhino were developed to program Gcode for the Hotwire machine. Each panel requires its own code of several hundred or thousand coordinates. The Hotwire machine is limited to defining ruled surfaces.
The foam molds are then transferred to a large 5-axis CNC router which machines the foam molds to the final panel shape. The 5-axis machine defines critical indexing keys and other alignment geometry. Toolpaths are programmed using Delcam’s Powermill software.
The SFMOMA façade panels will be the largest architectural application of composites technology in the United States. Kreysler & Associates developed the first composites system (patent-pending) to successfully pass the NFPA 285 multi-story fire-resistance test, required for such extensive use of composites in façade applications. The composite panels will have a sand-blasted polymer concrete finish.
The rippled façade of the new SFMOMA building is an example of how cutting-edge digital fabrication and composites technologies are transforming the face of our built environment.
Photography: MIR and Snohetta
Read More: ArchDaily article