Sawtooth scanning strategy for additive manufacturing

PurposeThis study aims to improve the acceleration in the additive manufacturing (AM) process. AM tools, such as extrusion heads, jets, electric arcs, lasers and electron beams (EB), experience negligible forces. However, their speeds are limited by the positioning systems. In addition, a thin tool must travel several kilometers in tiny motions with several turns while realizing the AM part. Hence, acceleration is a more significant limiting factor than the velocity or precision for all except EB.Design/methodology/approachThe sawtooth (ST) scanning strategy presented in this paper minimizes the time by combining three motion features: zigzag scan, 45 degrees or 135 degrees rotation for successive layers in G00 to avoid the CNC interpolation, and modifying these movements along 45 degrees or 135 degrees into sawtooth to halve the turns.FindingsSawtooth effectiveness is tested using an in-house developed Sand AM (SaAM) apparatus based on the laser-powder bed fusion AM technique. For a simple rectangle layer, the sawtooth achieved a path length reduction of 0.19%-1.49% and reduced the overall time by 3.508-4.889 times, proving that sawtooth uses increased acceleration more effectively than the other three scans. The complex layer study reduced calculated time by 69.80%-139.96% and manufacturing time by 47.35%-86.85%. Sawtooth samples also exhibited less dimensional variation (0.88%) than zigzag 45 degrees (12.94%) along the build direction.Research limitations/implicationsSawtooth is limited to flying optics AM process.Originality/valueDevelopment of scanning strategy for flying optics AM process to reduce the warpage by improving the acceleration.