A company is dealing with difficult production of drive shafts. Milling is done on a shaft with a low number of teeth with a large module, which means large quantities of extraction material and demanding conditions during processing. Two machines of the same type were tested in order to determine which one is more capable of producing the mentioned drive shafts.
SPC analysis was done on both machines and later, the results between them were compared. Before starting the analysis, the capability of the measuring device Gearspect was checked, which is used for testing gears and drive shafts with gears. It was checked using the analysis of measurement systems MSA.
The MSA analysis showed that the testing device used is just about capable enough for our application. The SPC analysis showed that both machines have narrow dispersion. The problem lies in a location error, because the process tends towards the upper tolerance limit. Despite some small differences, the more suitable machine was chosen, in our case machine number 132, which will be used to manufacture drive shafts with difficult production parameters. Improvement of central tendency of process was done by lowering feed rate during the production of drive shafts in order to improve capability of both machines.