Writing in JLC‘s sister publication, Architect, Gideon Frank Shapiro describes the development of “zippered wood” – an intriguing way to bend 2x4s to create unusual framing shapes:
Blair Satterfield
“The ‘aha!’ moment at the University of British Columbia’s HiLo Lab came when researchers, intent on bending strips of wood veneer into unusual forms, stepped back to look at their elaborate setup. ‘We realized we could use the formwork itself as the member,’ says Blair Satterfield, chair of UBC’s architecture program and an associate professor …
… Starting with a cross-cut saw, the team created kerfs along 2×4s, enabling them to bend and twist. Using Grasshopper [an algorithm written for Rhino 3-D modeling software] and the Kangaroo plug-in, they modeled the results and then wrote software protocols to map tooth patterns to specific curvatures. They upgraded to a CNC mill to cut teeth into 2×4s in such a way that two separate pieces of wood would lock or “zipper” only when they are hand-twisted together into the desired position, no wood steaming or soaking required. The mated pieces are clamped and glued to form a curving composite member with the dimensional cross-section of a 2×4. ‘Anecdotally, these bent and joined members are much stronger than a straight stud,” Satterfield says. “It’s unbelievable how much force they can take.'”