Layer to layer registration of a slurry-based 3D printing machine

Abstract

Slurry-based 3D printing is a new technology designed to further increase the feature resolution capabilities of 3D printing. This technology deposits an unprinted wet slurry layer by rapidly depositing overlapping parallel lines of slurry to form each layer. Line registration may affect the final properties of the part and it is therefore desirable to control the registration of slurry lines within each layer and from one layer to the next. A galvanometer was used to adjust nozzle position to compensate for line position errors. The galvo correction was calculated and actuated using a PMAC controller running programmable logic controller programs. The line spacing controller is successful in improving line spacing and registration over open loop performance. However, the degree of line position improvement is not certain due to measurement errors. Because of the large measurement variability, the line spacing may actually be better than measured. Developing more accurate diagnostics is important to determine the accuracy of the line position controller. More importantly, the effect of different line registration patterns on layer and part characteristics should be investigated.