Roboticus tignarius: robotic reproduction of traditional timber joints for the reconstruction of the architectural heritage of Valparaíso

Abstract

The architectural heritage of Valparaíso, Chile is disappearing before our eyes while all the conventional resources to reverse this situation seem to have been exhausted. A large portion of the existing historic building substance consists of timber frames that succumb one after another to weathering, termites and structural fires. The acute shortage of traditional timber framers and a weak local heritage industry feed investors’ disinterest in preserving the original structural conception of these timber-framed buildings when they need restoration or rehabilitation. There is a need for technological innovation enabling one-off production of complex-skilled joinery at competitive costs. Robotic machining emerges as a flexible and customizable alternative to the missing timber framers and the insensible substitution of original timber joints for metal fasteners. We present a proof-of-concept of parametric 3D modelling and robot path generation using a single visual scripting environment integrated to CAD software that requires no knowledge of robot programming and might encourage designers as well as small- and medium-sized manufacturers to develop a local heritage industry. Several classes of timber joints found in Valparaíso were parameterized and instances thereof manufactured by a six-axis industrial robot with a spindle mounted thereon to gain empirical knowledge of the entire process. Experimental results show that procedural modelling of parts, assemblies, and tool paths in the tested visual scripting environment is time-consuming and rather complicated for conventional architectural thinking, but is largely compensated by its software and hardware interaction potential.