In many metal processing industries, such as tool and mold making, there is an increasing demand for individually designed components in small series. Particularly in simultaneous five-axis milling, process optimization on the machine leads to high efforts in process design and material costs. Achieving accurate production of good parts on the first attempt saves costs and provides small and medium-sized enterprises with increased competitiveness in the international market. However, ensuring this requires a reliable design of manufacturing processes.
Currently, process design is based on empirical values for process parameters and geometric calculations of the tool path. The actual machine dynamics, such as inertia and acceleration limits of the machine axes, are not considered in the tool path calculation. As a result, the actual tool path taken by the machine does not exactly match the one calculated in the CAM system.
When the geometry of the manufactured component deviates from the planned shape, it often leads to significant post-processing efforts and additional costs. Minimizing post-processing efforts and being able to efficiently and flexibly manufacture customized components provides companies with a competitive advantage and ensures greater resilience to market changes.
In the research project "M-TOPP - Machine-Tool Optimized Path and Process Planning," the project partners are developing a digital method that systematically considers machine-specific influencing factors in tool path planning. To achieve this, the project team is expanding the functionalities of an NC analysis software developed at Fraunhofer IPT for machine-optimized process planning and integrating it into a CAD/CAM system.
With the help of the optimized NC simulation software and its coupling to the CAD/CAM system, it will be possible in the future to determine the relationship between process planning and the actual machining result more accurately. This significantly reduces process design time and greatly improves component quality at the beginning of manufacturing compared to conventional approaches.
For their research work in the project "M-TOPP," the project team utilizes the software "NCProfiler" developed at Fraunhofer IPT (link to brochure), a tool for analyzing and simulating NC code. The "NCProfiler" takes into account machine kinematics data, as well as information about the dynamic characteristics of individual axes and specific control properties for the analysis. It supports all common NC formats, such as Heidenhain iTNC, Sinumerik, or ISO-NC, as well as intermediate formats like APT or CLDATA.
The project team integrates the NC software into an existing CAD/CAM environment through a web connection as a microservice. By coupling the two programs, CAM programmers can not only plan tool paths but also analyze and simulate the machining process for specific machines, including machine kinematics.
To enhance the quality of machining results on the milling machine from the first attempt, researchers expand the NCProfiler by incorporating machine-specific influencing factors such as machine control, dynamic limits, and process configuration (clamping situation, machine type selection).
The enhanced simulation software visually alerts operators when the planned tool path does not lead to the desired workpiece result on the respective machine in reality.
To make the NC simulation applicable to various processes and machine types, the team develops a novel calibration method using standard machine investigations. Simple axis movements are performed on different milling machines, and data regarding influencing factors like inertia and approach times are collected.
With the gathered data, a machine configuration file is generated and made available to the NCProfiler. The result is the consideration of influencing factors such as machine control, dynamic limits, and process configurations in NC path generation. The NC path can be planned and simulated with less effort and more relevant influencing factors.
The expanded and more flexible NC software will be validated in the final stage of the project using a demonstrator component through five-axis milling operations.
The research project "M-TOPP - Machine-Tool Optimized Path and Process Planning" is funded by the Federal Ministry for Economic Affairs and Climate Action (BMWK) as part of the funding program "IGF - Industrial Collective Research"
Funding code: 22184 N/2
Project Management Agency: Aif/ IGF