A parallel-based path generation method for fused deposition modeling

This paper proposes an approach to parallel filling path generation based on adaptive gaps for fused deposition modeling (FDM) with full consideration of technology characteristics of this promising fabricating method. At first, analysis on the similarities and differences between FDM and the conventional milling manufacturing is conducted from the tool-path planning perspective. Meanwhile, some specific features of FDM are analyzed in detail to point out three critical issues in the path planning process which is correlated with the fabricating quality and modeling accuracy. These issues are described specifically by means of theoretical analysis and practical fabrication: large number of uncut paths, sharp corners in the filling path, and overfill and underfill phenomena which are out of the constant gap between parallel paths. The proposed tool-path generation method determines the inclination of the reference line based on less number of sharp corners in the paths firstly. Then, the filling area is divided with three stages. The pre-sweeping stage employs a group of paralleling lines with pre-determined gaps and optimized inclination to intersect the filling boundaries and stores the intersections between them, the second stage adjusts some sweeping line segments which satisfy several specific conditions, and the last stage divides the filling areas into several sub-regions according to the selected sweeping lines. Subsequently, the sweeping lines within each sub-region are adjusted adaptively to uniform gaps individually. At last, some adjacent sub-paths that can be connected to decrease the number of uncut paths are linked. Relative performance evaluation and experimental analyses are provided to demonstrate that the proposed methods can enhance the fabricating quality significantly with some improvements in the machining efficiency.