Abstract:
Dynamometers are being used in the industry and academia to measure power, force and torque. Dynamometers basically work on the principles of either absorption or transmission. The design of dynamometer primarily depends on the requirement of measurement of forces or torque. Strain gauge based dynamometers are quite reliable and accurate. Cutting forces, like in case of milling machining process can be gauged by dynamometer. Milling is a widespread machining process being used in the manufacturing industry all around the world. A wide range of intricate shapes can easily be manufactured by milling process. Initially conventional machining was in practice, however, CNC milling increased the possibilities of machining with higher production rates and improved accuracies. However, every manufacturing process needs to be optimized to produce economical products. Tool wear is one of the major factors which increases the cost of milling processes. This tool wear is caused by the cutting forces in milling due to type of material, DOC and feed rate. these need to be optimized to minimize tool wear and increase tool life. To achieve this, monitoring of forces is of paramount importance. This report describes the development of a strain gauge based dynamometer to measure cutting forces involved during milling. Dynamometer designing is carried out on the basis of data of cutting forces of hard to cut materials which is available from previous research. FEA was carried out to ensure that the dynamometer is rigid enough to withstand the cutting forces. Moreover, the FEA showed promising results that the dynamometer is deformable also. After manufacturing and assembled and tested after calibration. Keeping in view results of calibration, Cross-sensitivity tests have been conducted. AISI4340 was chosen for experimentation. This material is high strength steel alloy and has good impact properties. A repeatable experimental setup and procedure is developed for measuring and recording the three components of cutting forces. During the experimentation nine times, only cutting tool was replaced by new one if required. The results of milling of AISI4340 with carbide coated tool was gathered and analyzed.
