Machining Process and CNC Programming for Francis Turbine Guide Vane Manufacturing

• Main Author: Setyanto, Andreas
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42951
• Institution: Institut Teknologi Bandung

Hydroelectric power plant is one of many types of power plants that are still operating in Indonesia. Francis turbine is commonly used in a typical hydroelectric power plant. Problems are often faced in a hydroelectric power plant that uses Francis turbine, one of which is the relatively low durability of its Francis turbine guide vanes. This problem is caused by unwanted materials which are carried by water that flows from the surrounding river. Should there be any damage caused by erosion, guide vanes must be bought from their original equipment manufacturers. In order to reduce the expense of procuring guide vanes, it is better to produce Francis turbine guide vanes through reverse engineering method. A reverse engineering method consists of many processes from collecting informations to its manufacturing process. The manufacturing process of a guide vane is complex. Thus, the use of nonconventional machinery such as CNC machine is needed. In this study, the machining process is explained from engineering drawing identification, fixture design, tool selection process, to its CNC programming. Cimatron E11 was used to obtain the G-code, a language that is understood by CNC machines. Based on the process planning, guide vane is manufactured using three machines such as turning, conventional milling machine, and CNC milling machine. The process consists of facing, centering, turning, chamfering, and milling process with CNC milling machine. The result of CNC programming shows that the program could provide a good surface finish with deviation ranges from -0.01 mm to 0.01 mm for the pressure side and -0.01 mm to -0.02 mm for suction side. Both pressure side and suction side tolerances are acceptable by the engineering drawing made by designer.