Robotic processing of crooked sawlogs for use in architectural construction

Abstract

In this paper, ideas and methods for utilising crooked sawlogs in construction are presented. The paper discusses a current problematic reality and, through a selected scenario, proposes a workflow that handles a series of challenges that arises when working with irregular wood. Through an investigative working method and by utilising computation and digital manufacturing technologies, the workflow integrates material properties with architectural design tools. The research focusses on oak logs which have been discarded by the timber industry due to their irregular shapes. Oak is a hardwood with structural properties, but often grows into crooked geometries. Through procedures for 3D-scanning, data handling, analysis, and evaluation methods, informed machining and utilisation of the logs are made possible. Numerous crooked sawlogs are handled in parallel physical and digital stockpiles. The digital stockpile holds layers of information generated from the sawlogs. When given an input geometry, the workflow matches the geometry with sawlogs found in the digital stockpile, and using procedures for developing and detailing, a realised version of the geometry can be machined and constructed using digital fabrication methods. The workflow includes multiple custom-made methods and algorithms for handling the complex and different shapes and data of crooked sawlogs in a highly digitised machining and fabrication environment. A constant link and the dialogue between digital data and physical reality are maintained and used actively in both design and fabrication strategy. The suggested up-cycling of irregular sawlogs using non-standard methods is a critical articulation of today’s linear material economy as the research illustrates how the natural forms and properties of materials can be used to rethink existing design and material practise. This paper is an expansion and further development of work presented at ACADIA 2019 (Larsen et al. in Ubiquity and autonomy, The University of Texas at Austin School of Architecture, Austin, 2019).