An Improved Method for Cutting Force and Surface Error Prediction in Flexible End Milling Systems

Abstract

As more emphasis is placed on quality and productivity in manufacturing, it becomes necessary to develop models that more accurately describe the performance of machining processes. An improved model for the prediction of the cutting force system and surface error in end milling has been developed and has been implemented on the computer. This enhanced model takes into account the effect of system deflections on the chip load, and solves for the chip load that balances the cutting forces and the resulting system deflections. Such a model allows for the evaluation of cuts in which deflections significantly effect the chip load. The flexible system model predictions of forces and surface error are compared against both measured and rigid system model-predicted values associated with the machining conditions for experiments performed on the 390 casting aluminum alloy. It is shown that the enhanced chip load model gives predictions of both cutting force signatures and surface error profiles that are significantly better than the rigid system chip load model developed previously. The fact that system deflections temper the effects of runout, and reduce both peak cutting force and maximum surface error is demonstrated and discussed.

A prediction of the machining defects in flank milling

“…It stops when the deflection converges. Calculations with this method are very long and not quite acceptable in the CAD universe [21,22,23,24].…”

Cutting force prediction for ball-end mills with non-horizontal and rotational cutting motions

“…4). Identification of all the intersection points is needed in order to determine all the undeformed chip thickness candidates [3,4,29,35]. The smallest-value candidate is the undeformed chip thickness solution, which is taken as zero if negative.…”

“…For mechanistic cutting force modeling, this concept of undeformed chip thickness was first adopted for end milling by Kline et al [2]. This pioneering work was later extended to incorporate cutter runout and cutting system flexibility in the determination of chip thickness [3,4]. To further improve cutting force prediction accuracy, continued studies on the undeformed chip thickness determination in milling have been carried out by employing the true trochoidal cutting trajectory in horizontal linear tool motions [5,6] as well as in horizontal circular tool motions [7].…”

Tool path generation for milling of free form surfaces with feed rate scheduling

“…Many researchers have developed models for cutting force prediction in milling operations [15][16][17][18][19][20][21][22][23][24].…”