Contour Crafting is an emerging technology that uses robotics to construct free form building structures by repeatedly laying down layers of material such as concrete. The Contour Crafting technology scales up automated additive fabrication from building small industrial parts to constructing buildings. Tool path planning and optimization for Contour Crafting benefit the technology by increasing the efficiency of construction especially for complicated structures. The research reported here has aimed at providing a systematic solution for improving the overall system efficiency and realizing the Contour Crafting technology for building customdesigned houses. In the Part I of this paper an approach is presented to find the optimal Tool path for the single nozzle Contour Crafting system incorporating the physical constraints of the technology and construction considerations. In Part II several algorithms are presented for finding the collision-free Tool path for multiple machine configurations based on the single nozzle approach. The multiple machine configurations of Contour Crafting are ideal for rapidly constructing multiple adjacent structures or a large single structure because all machine modules can work in parallel to concurrently fabricate various structural parts.

Contour Crafting is an emerging technology that uses robotics to construct free form building structures by repeatedly laying down layers of material such as concrete. The Contour Crafting technology scales up automated additive fabrication from building small industrial parts to constructing buildings. Tool path planning and optimization for Contour Crafting benefit the technology by increasing the efficiency of construction especially for complicated structures. The research reported here has aimed at providing a systematic solution for improving the overall system efficiency and realizing the Contour Crafting technology for building customdesigned houses. In Part-I of this paper, an approach is presented to find the optimal Tool path for the single nozzle Contour Crafting system. The model developed incorporates the physical constraints of the technology as well as some practical construction issues. In Part-II several algorithms are presented to find the collision-free Tool paths for the multiple-nozzle system based on the algorithm developed for the single nozzle approach.