Design and machining analysis of a novel wheel-based mobile machine tool

Abstract

This paper presents the design and machining analysis of a new type of wheel-based mobile machine tool (MMT). Our MMT prototype performs machining processes while moving, thus improving time and cost inefficiencies by eliminating procedures such as assembly, disassembly, and transport of workpieces required when machining large workpieces using conventional machine tools. The wheel-based MMT design has simple kinematics, resulting in less complicated control and programming compared to other MMTs. For our MMT, maximum external forces that can resist slip was derived through friction analysis, supporting the machining analysis. A stability lobe diagram (SLD) tailored to our MMT design was created to evaluate the MMT's machinability and stable machining conditions. The reliability of the SLD was verified experimentally through a comparison of the MMT-machined surfaces, acceleration and cutting force data with those resulting from Al-6061 slot milling experiments using the MMT. The validation results of the MMT's cutting force simulation numerically supported the reliability of the SLD. Furthermore, our analyses indicated that spindle displacements can be used as machining monitoring factors, without compromising MMT mobility. Based on our analyses of machining experiments and simulation results, the proposed wheel-based MMT is promising for practical implementation.