Tamar Nix

In the past decade, additive manufacturing processes have exhibited immense potential by pushing the boundaries of material exploration. Involving the construction of volumetric objects through adding flat knitting machines has gained recognition as an additive manufacturing technology since they possess the unique capability to directly fabricate three-dimensional articles from yarn. Nevertheless, while flat knitting machines have made significant strides in the production of three-dimensional textiles, they still face hurdles in handling intricate structures, achieving large-scale production, and accommodating a wide range of yarns. This article proposes crochet as a feasible substitute for knitting in multi-scale applications, owing to its inherent ability to create seamless three-dimensional shells. Despite recent progress in computing crochet instructions, the absence of a digital fabrication technique for volumetric crochet within the framework of additive manufacturing remains a notable gap. This paper provides a thorough examination of the recent advances in computational crochet design tools. It then proceeds to analyze crocheting hand gestures and toolpaths to identify the pertinent design characteristics for a novel technology. Lastly, the paper introduces a pioneering digital fabrication device specifically designed for robotic crochet frameworks. This device underscores the notable advantages of crochet in comparison to other related fabrication methods.

There is growing interest in incorporating digitally fabricated textiles into architecture. While most studies have addressed knitting and yarn winding, only a handful have involved crocheting. Crochet is a traditional handcraft that uses a hook to create fabric from a single yarn. Crochet is exceptional in its capability of creating seamless complex 3D shells. Despite significant progress attained in the computation of crocheting instructions, which positions it in an additive manufacturing context, a rigorous fabrication solution for crochet is still lacking. The present study examines the possibilities of applying additive manufacturing principles for adapting crochet from handcraft into digital fabrication using a robotic arm. The experimental phase focuses on toolpath design, targeting the primary steps involved in the performance of crochet stitches using a robotic arm. Initial stages include a manual scheme, using 3D-scanned pre-prepared cloth as a foundation for path design, and recording the crochet hook path in digital format. This study defines the first steps in transitioning crochet from handcraft to a robotic process and establishes the method's feasibility based on the computational design of the tool path. Robotic crochet enables the production of remarkably complex seamless 3D textiles in large-scale formats and opens the field to architectural applications.