Comparative analysis of the ISO tolerance class of 3D-printed spur cylindrical gears produced with material extrusion and powder bed fusion techniques

The present work correlates the printing accuracy of two major 3D-printing techniques applied for the production of spur gears by calculating the ISO tolerance class that defines the accuracy level of gears in all industrial applications. Specimens were produced using material extrusion MEX-TRB/P/ABS and powder bed fusion PBF-LB/P/PA22 techniques, evaluated by using a touch-probe coordinate measuring machine (CMM) with appropriate software and finally compared in terms of standards gear geometry errors and deviations. MEX-TRB produced specimens exhibited higher levels of accuracy and ISO quality class correspondingly. Both sets of specimens were found to comply with ISO Q12 or higher that greatly varies from the quality class of most metallic gears used in industrial applications. The printing parameters are detailed and discussed extensively in an attempt to provide insight on further research and process optimisation for the production of AM gears.