This paper studies the influence of FDM (Fused Depositing Modeling) parameters on gear stiffness made of Polylactic Acid (PLA). 3D printing parameters must be optimized because they influence the physical, mechanical, and quality characteristics of the additive manufactured part along with its functionality. The objective of this research is to optimize FDM parameters in order to obtain the highest stiffness. In this context, we used Finite Element Analysis (FEA) and we made experimental tests to validate its results. The experimental tests are divided into two categories, gears with the same parameters and gears with the same layer height and variable filling percentage. The average results of gear stiffness with the same parameters are 8.18% highest than the average results of gear stiffness with the same layer height and variable filling percentages.

This paper presents the results of a theoretical-experimental study on the influence of FDM parameters (height of the deposited layer at one pass Hs and percentage of filling Pu) on the dimensions of cylindrical spur gears made of PLA (shaft diameter d and bore diameter D). In this context, we designed the 3D model of a cylindrical gear with module m= 1 and z= 60 spur teeth, which we used for FDM 3D printing of 27 PLA parts with different values of coating height deposited at a pitch Hs of 0.10, 0.15, 0.20mm and different values 50, 75, and 100% of filling percentage Pu. The 324 values obtained from measuring the diameters d and D of 27 cylindrical spur gears made of PLA and the calculated values of statistical indicators (arithmetic mean, standard deviation, dispersion) were used to determine the dimensional accuracy of the analyzed parts. The study results show that the percentage of filling has a greater influence than the shaft diameter on the dimensional accuracy of cylindrical spur gears made of PLA.