Fab Lab has a tradition of creating a mechanical Pookkalam (traditional floral pattern) each year. When brainstorming fresh concepts, the CRF team approached me with a video exploring expanding kinetic iris geometry, inquiring whether it was physically achievable within our fabrication deadlines.
Mechanical Pookkalam
Synchronized ring-gear linkage inspired by Hoberman spherical geometries.
Operating mechanical floral deployment mechanism
Investigating the mechanism revealed strong mathematical parallels to Hoberman linkages, famously used in expanding geodesic spheres. I parameterized the scissor joints and modeled an animated proof-of-concept CAD assembly to validate synchronization.
Next came automation. We synchronized the expanding arms using three high-torque stepper motors coupled through an external ring gear mechanism. While visually resembling a planetary gear assembly, the design operates without a central sun gear, utilizing the outer ring perimeter to preserve torque across all petal nodes in tandem.