Rapid prototyping (RP) is a technique for direct conversion of 3D computer-aided design (CAD) data into a physical prototype using standard triangular language (STL) file format. In the STL file conversion process, there is a need to address the tolerance issues that may affect the RP output. The accuracy of the CAD model is affected by the tolerance, which also affects other factors in turn. To meet the objective of the study, a sphere shaped object was modeled and several STL files were generated using different tolerance values. The file size and the number of triangular facets are recorded after STL file generation while the number of file errors is obtained after scanning. Using the CAD model, the surface finish of the STL models were also compared. This paper provides a general view of how the file size, the number of triangular facets, the number of errors and the surface finish vary with the tolerance. The study provides clear evidence that the ASCII file size is considered to be six times that of the binary equivalent along with a significant decrease in the size of both the file types with an increase in tolerance
