Joinery Solver for Whole Timber Structures

This paper presents a digital joinery generation method for whole-timber structures using wood-wood connections. The research is based on a collaboration with a local timber company located in a mountain area [1]. In this context, there is a need to explore available round-wood stock to increase its use and apply it to the local construction. The inspiration is taken from joinery generation methods [2,3] and applied to round-wood timber assemblies. The joinery solver considers: available stock of timber, its natural characteristics (i.e. irregularity in section, length, curvature, forking), low-poly digital representation and digital fabrication (CNC, Robot tool-path). First, round-wood is scanned and point-clouds are processed to get the central-axis and radii. Second, trunks are oriented to a design space. Third, the joinery solver creates connections. This method is based on a tiling process when a group of polylines are scaled, sheared and translated to a connection zone. The joinery library is collected from existing literature and classified i.e. side-side, side-end, end-end types. The research shows that it is possible to automate joinery generation while examining variability of timber and digital fabrication constraints. The joinery solver is validated by physical tests using 4.5 CNC and 6-axis ABB robot.