Generalized cutting force model for peripheral milling of wood, based on the effect of density, uncut chip cross section, grain orientation and tool helix angle

Abstract

The influence of the grain angle on the cutting force when milling wood is not yet detailed, apart from particular cases (end-grain, parallel to the grain, or in some rare cases 45°-cut). Thus, setting-up wood machining operations with complex paths still relies mainly on the experience of the operators because of the lack of scientific knowledge easily transferable to the industry. The aim of the present work is to propose an empirical model based on specific cutting coefficients for the assessment of cutting force when peripheral milling of wood based on the following input: uncut chip thickness and width, grain angle (angle between the tool velocity vector and the grain direction of the wood), density and tool helix angle. The specific cutting coefficients were determined by peripheral milling with different depths of cut wood disks issued from different wood species on a dynamometric platform to record the forces. Milling a sample into a round shape (a disk) allows to measure the cutting forces toward every grain angle into a sole basic diameter reduction operation. Force signals are then post-processed to carefully clean the natural vibrations of the system without impacting their magnitudes. The experiment is repeated on five species with a large range of densities, machining two disks per species for five depths of cut in up- and down milling conditions for three different tool helix angles. Finally, a simple cutting force model, based on the previously cited parameters, is proposed, and its robustness analysed.

10th Hardwood Conference Proceedings

“…The effect of cutting condition on the qualitative and quantitative parameters of strain field near the cutting edge was studied in a greater detail. The FA affected primarily the quantitative parameters, which is in agreement with Curti et al (2021). The increasing FA increased the both tension and compression strain magnitude in the same manner for hardwood and softwood.…”

Research on the End-Milling Surface Quality of Paulownia Based on Response Surface Model in Terms of Force and Chip Morphology

“…Some studies have shown that, in wood material processing, cutting tools and cutting parameters have a decisive effect on the surface quality [7,8]. No matter whether one is milling soft or solid wood, it has been found that the cutting angle, feed speed, wood fiber orientation angle, and milling depth that are used have significant influences on the cutting force, chip formation, and surface quality [9,10]. As a typical soft wood, Paulownia requires fundamental investigation into its machinability due to the currently lack of information surrounding it in the literature.…”