Rotary axis calculation for five-axis FDM printer using a point-fitting optimization method

This paper presents an optimization method to compute the rotary axes of a 5-axis FDM printer whose A- and C-axes have large deviations relative to the x- and z-directions. The optimization model is designed according to the kinematic model in which a point rotates around a spatial line in the machine coordinate system of the printer. The model considers the A- and C-axes as two spatial lines. It is a two-object optimization model including two aspects. One is that the sum of deviations between the measured and computed points should be small; the other is that the deviations should be uniformly distributed for every measured point. A comparison of the new optimization method with conventional error-compensation methods reveals that the former has higher location accuracy. Using the optimized AC axes, 5-axis 3D printing paths are planned for some complex workpieces. Data analysis and printing samples show that the optimized AC axes satisfy 5-axes FDM printing requirements for nozzles with a diameter of 1.0 mm.