Influence of printing time reduction on dimensional accuracy of final build FDM parts by modifying the G-code program

In the material extrusion process, dimensional accuracy and printing time depend on the printing process parameters. Due to consistent layer height, traditional material extrusion takes a long time to print at low-thick layers. The current research proposes a novel way to print low-layer thickness at crucial dimensions and alter the RepRap flavor G code to print the rest with a higher-layer thickness. The current research has decreased printing time by 22.5% over the conventional material extrusion process. This work also presents a novel approach for Z-direction dimensional accuracy. The slicing software determines the total number of printing layers based on the material extrusion thickness and the model's total height. When the total number of layers results in decimals, the decision to print a decimal layer depends on the percentage of the decimal value in the layer thickness. This study found that if the percentage of the decimal value is equal to or more than half of the layer height, slicing software will accommodate a layer; in this case, the final height of the part will be oversized. If it is less than half of the layer height, slicing software won't accommodate the layer; in this case, the height of the part will be undersized. Adopting this method improves dimensional accuracy in the Z direction by editing the code for decimal value, and optimizes material and energy consumption for oversized components. Similarly, the component's linear dimensions are determined by layer width and extrusion percentage. If the extrusion percentage increases, the linear dimensions of the component will also increase. This approach can be used on all geometrical shapes and materials to print critical dimensions with a lower layer thickness and the rest with a higher layer thickness. The printing process parameters, type of material, and geometry complexity do not affect the method's efficiency.