Experimental investigation of the influence of cutting tool rake angle on forces during metal cutting

Ill EXPERIMENTAL INVESHGATION OF THE INFLUENCE OF CUTTING TOOL RAKE ANGLE ON FORCES DURING METAL CUTTING (M. Sc. Thesis) Mustafa GUNAY GAZI UNIVERSITY INSTUTE OF SCIENCE AND TECHNOLOGY July 2003 ABSTRACT In this study, evaluation of the influence of cutting tool rake angle on the cutting forces during chip removal operations from a rotating part using a stationary cutting tool has been aimed. For this purpose, a dynamometer was designed and constructed in order to measure cutting forces using two beam type load cells suitably placed according to the CNC lathe and the cutting tool. By doing so, the deflection of the cutting tool under cutting forces was aimed to be determined. The signals sensed by the load cells at "mV" level were amplified to "V" level. The obtained cutting force data was recorded on a computer using I/O card and then analysed. Cutting tests were carried out on a AISI 1040 work piece material whose properties are well known at five different cutting speeds while depth of cut and feed rate were kept constant 8 different rake angles from negative to positive were selected and during each test the primary (Fc) and feed (Fa) forces were measured. The results showed that positively increasing rake angle decreased the primary cutting force. The lowest feed force was obtained at 0° rake angle and positive and negative rake angle increased this force. Surface roughness measurements were also carried out on the cut surfaces and it was seen that rake angle did not have a remarkable influence on the surface roughness. A comparison was also made between the measured andIV theoretically calculated cutting force to verify whether this dynamometer can measure the cutting forces with required accuracy. Science Code : 626.12.01 KeyWords : Cutting forces, rake angle, dynamometer, load cell, machinability Page Number : 119 Adviser : Prof Dr. Ulvi ŞEKER