Robotically-fabricated nexorades from whole timber

Abstract

This paper introduces the conceptual design of sustainable timber structures using raw wood. It presents a workflow for systematically generating Nexorades using a tiling method for multi-valence quad subdivided surfaces. The system is designed based on an integrated framework combining resources from local forestry, knowledge from geometry processing, joinery for raw wood, laser scanning and digital fabrication, and structural engineering. Particular focus is given to Cross joint geometry and tool-path generation. Also, the global structural performance of the system is assessed. The results indicate that the proposed design methodology can offer an efficient and sustainable construction technique. Furthermore, the methodology is reflected in a robotically fabricated prototype, demonstrating that the design framework can seamlessly integrate digital tools and construction.

Toward Cost-Effective Timber Shell Structures through the Integration of Computational Design, Digital Fabrication, and Mechanical Integral ‘Half-Lap’ Joints

“…In this section, we explore half-lap joints adapted to the limitations of 2-axis CNC cutting. These joints are versatile for double-curvature structures [30], reciprocal structures, and flat assemblies such as walls and slabs. Practical examples of their use include the New View pavilion by Nabaei and Weinand [31], which employs plywood joined by "U" cuts, and studies on reconfigurable folding structures by Agostino and Pone [32].…”

Construction Robotics: From Automation to Collaboration

“…However, when combined with robotic assembly, the use of the robot overcomes the need to reposition and reprocess the working piece, which may also decrease tolerances and allow for more design possibilities (20). Applications of subtractive robotic processes range from cutting and sawing (21)(22)(23)(24), milling (25)(26)(27), and drilling (20) to carving (28). Besides additive and subtractive processes, we can also delimit deformative processes, such as wire bending (29,30), metal sheet bending or folding (31,32), and incremental sheet forming (33).…”

“…Typically, the imprecisions registered by the camera are translated back into the 3D model so that the subsequent construction steps can be corrected and accurately performed, an approach that also avoids the uncontrolled accumulation of tolerances; to achieve this, the digital model is adjusted every x number of steps so that the fabrication process can adapt to those changes. The use of 3D scanning data also allows the processing of existing objects, such as found or irregular material (88), enabling a new approach to construction that does not rely on materials being processed into standardized regular shapes and can instead work with on-site and raw materials (26,45,89,90). Similarly, visual information allows for adaptive robotic processes in which the exact movements are defined based only on sensory data of the workpiece (67) or processes that can adapt to changes in the environment (64,91).…”

Elements of a Timber Lamella Structure: Analysis and Systematization of Joints

“…The first type is usually used for carpentry and classical roofs. The second and third types are interchangeably used, depending on the structural loads of each joint in the structure, while joints with adhesive are still being researched [15]. Joints for timber lamella structures have changed over the past century, from simple bolt joints to experimental ones using plates, bolts, and dowels.…”

“…This characteristic of lamella structures is one of the reasons to reconsider their use in contemporary construction practice. This is guided by the development of new technologies and digital fabrication, which enable uncomplicated production of elements (for example, on CNC machines), faster construction, and economic structures, all following the trends of sustainable development [14,15]. The small number of lamella types and their connections leads to a reduction in production costs.…”