Cutting pressure models have long been utilized for calculating machining force components both tangential and normal. This work lists literature-reported closed form analytical models for torque and thrust of material cutting pressures. Typically, these models are equations formulated in terms of process parameters including mainly cutting speed (V, m/min), feed (f, mm/rev), and tool rake angle (α, degrees). This work aims to benefit from the variation in rake angle and cutting speeds encountered along the lip cutting edge of a standards twist drill to generate normal and tangential cutting pressure empirical models for aluminum 6061-T6 material based on a limited number of drilling feed rate and spindle speed combinations. To isolate the 10mm twist drill bit cutting edge forces, drilling experiments were conducted utilizing 2.5mm pre-cored workpieces. Cutting lip edge toque and thrust data were collected from conducted series of drilling experiments with total number of 10 varying combinations of feed rate and spindle speeds.
Values of cutting pressure in terms of feed, speed, and rake angle parameters were identified using a custom-developed MATLAB® code. Minimized is the difference between the cutting pressure-based closed form torque and thrust models versus the experimentally collected cutting lip torque and thrust measurements. Based on this MATLAB® code, cutting feed, speed and rake angle parameters found around −0.2, −0.1 and 1.5 respectively based on a convergence criteria of 10−10 and maximum iteration number of 1000. These optimized cutting pressure parameters were found to predict well the collected experimental forces and were found to be in line with parameter values as reported in the literature.