Overview
Made of plywood, PTOLEMi is a pair of curved wall structures that uses an algorithm based on a reciprocal system. Demonstrating that through computation, timber products can be a structurally sound material for use in a complex spaceframe. PTOLEMi stands at 3.8 meters with a 6.4 meter diameter without fasteners such as nails or screws. As integrated into the algorithm is a mechanism that interlocks the plywood panels and contributes to its structural efficiency.
These plywood panels were pre-fabricated and labelled with a number system effectuating a one-day construction. Designed for a 5-axis CNC router, each plywood panel is unique in shape and size and was digitally fabricated for timely delivery and accuracy.
With a budget of $10,000, the project needed to meet very strict criteria in design, fabrication, construction and installation. The construction and installation of such a project must be carried out efficiently and economically. With this in mind, componentry must be prefabricated to enable a workflow that is systematic and intelligent. The use of plywood, for its structural integrity and versatility was necessary. Structural plywood is celebrated in PTOLEMi’s aesthetic scheme. The integration of innovative practices in this project enables basic materials such as plywood to be featured in a sophisticated design.
Structure
These curved wall structures are made of interlocking plywood panels. As a spatial intervention, these plywood structures offer a site-specific appeal in its form and function. The design is based on a curved and sloping grid making each component unique in shape and size. The highest point of the slope measures 3.8 meters with the lowest being 1 meter and curved to form a half circle with a diameter of 6.4 meters.
To enable the use of planar off-the-shelf plywood, these curved walls are faceted. Horizontal members use 15mm structural ply along the exterior and interior faces. They intersect with vertical members made of 25mm structural ply that function as columns. Each member interlocks with at least three other members via notches at intersection events. These notches secure each member and provide their stabilising detail.
Exterior plywood panels are layered with 0.8mm stainless steel in mirror finish, similarly locked in place through notches of intersecting plywood panels.
This engineered timber was chosen for economy, availability and its versatility in digital fabrication. In digital fabrication, plywood is often a preference for prototyping and ultimately, in this case, for end-use due to its structural integrity.
