Minghui Hao

Theoretical Estimation of Machined Surface Profile Based on Cutting Edge Movement and Tool Orientation in Ball-nosed End Milling

Abstract This paper presents the theoretical estimation method of machined surface profile without actual machining in ball-nosed end miling. The fundamental simultaneous equations of identifying the cusp height at any point of a workpiece in the simulated surface have been successfully derived from the geometric relationship between the cutting edge movement and the normal line at the point. By the numerical calculation, the machined surface profile can be estimated and illustrated graphically. It was found that the maximum and minimum cusp heights exist in a narrow range of tool orientation less than 3 degrees near the normal direction.

Geometric Generating Mechanism of Machined Surface by Ball-nosed End Milling

Abstract This paper presents a new geometric estimation method of machined surface by ball-nosed end milling in sphere contouring. Firstly the geometric relationship between a cutting edge and a normal vector of the sphere has been formulated. Through the equation analysis, multi-crossing of them up to three times and the zigzag movement of the cutting edge have been found newly. Also the interference by a major flank was found too. Secondly a numerical calculation solver was developed by Newton-Raphson method. Thirdly the graphical display was realized by a CAD system. Through the observation of machined surfaces, the interference area was confirmed.

Optimal tool selection based on genetic algorithm in a geometric cutting simulation

Abstract This paper presents new methods of offset surface generation and milling tool selection. Firstly the calculation of a workpieces area cut by a tool is done by detecting contact points between the tool and the workpiece in a lattice space model. Secondly the tool selection is made by Genetic Algorithm to minimize the total machining time and the uncut area. A tool set is coded as a binary bit string. It is assumed the tools would be used in the descent order of radius and cut their corresponding area as entirely as possible. Simulations and conclusions are briefly described.