Abstract:
This research presents an implementation of design of experiment to improve
production quality of the sprocket crank shaft. The study emphasized on identifying key
parameters affected the tensile strength resulting from the spot welding process. The preliminary
test indicated very low process capability (Ppk) of -1.39 with an average tensile strength of 3.2008
kN. The analysis for root causes was performed using SIPOC model and Cause and Effect
diagram. Effects of majority number of factors were indentified with utilization of the one-factorat-a-time
experimental design except material type, welding current and time. The full factorial
experiment was then designed and performed. The appropriate settings were determined to be 11
kA and 2 cycle for the welding current and time, respectively, with SK-85 metal sheet material
type. Implementation of the settings led to increment in the average tensile strength to 8.120 kN
with the Ppk of 0.93. Therefore, it can be concluded that the application of the experimental design
in this study assisted to improve the production quality of the Sprocket Crack Shafts significantly.