ULTRA HIGH PERFORMANCE CNC PROGRAMMING

This paper will provide a technical and industrial based application review of ultra high performance CNC tool path strategies. This will include a comparison of leading CAM systems VoluMIll, MasterCAM and SolidCAM. These... [ view full abstract ]

This paper will provide a technical and industrial based application review of ultra high performance CNC tool path strategies. This will include a comparison of leading CAM systems VoluMIll, MasterCAM and SolidCAM. These systems claim cycle time reduction of the order 50% and the paper will examine academic and industrial based case studies to evaluate this.

Ultra high performance CNC machining strategies incorporate constant step-over roughing, dynamic feedrate control for contour adjustment and constant material removal rates. They utilise the full tooling flute length (depth of cut typically >2 x tool diameter) with step up features for 3D sculptured surfaces. This enables the manufacturing process to achieve optimal material removal rates in roughing and finishing by providing total control of the tool engagement angle / step-over throughout the entire manufacturing cycle.

The CNC programming systems via dialogue boxes and / or slider bar control functionality provide tool path strategy adjustment ranging from conservative through to aggressive machining, morphing spiral control for precise control of the tool engagement angle and the integration of material, tooling and machine tool specifications to facilitate the determination of key machining parameters for optimal manufacturing performance.

This level of CNC programming capability is being developed by all leading CNC programming systems, provides the ability to develop optimised toolpath strategies, achieves significant cycle time reductions with considerable additional manufacturing benefits (extended tool life, stable spindle loading, extended high speed spindle life). These sophisticated CNC programming systems enable the CNC programmer to significantly enhance the performance of manufacturing resources. Data presented in the paper will quantify operational benefits with a range of materials including Stainless Steel 316, aerospace grade titanium, tool steels and aluminium.

The paper will also highlight the industrial application of these machining strategies through a Knowledge Transfer Partnership with LPE Ltd., Ulster University and the Northern Regional College (NRC). The company traditionally deployed additive manufacturing technologies for rapid product development. To compliment their core business they implemented a 5 axis CNC milling machine (Hurco VMX42SRTi) for the machining of components for their diverse customer base. The project required the capability to dynamically generate / verify complex multi-axis CNC programs incorporating advanced ultra high performance tooling and toolpath strategies. The Hurco machine tool included the Hurco UltiMotion option to optimise tool motion control with advanced CNC control software. This option facilitated the application of the ultra high performance tool path strategies and quantitative data will be provided to support this.