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When milling generally shaped surfaces with a ball-end milling tool, machined surface roughness and accuracy as well as machining productivity are often monitored. Improving one of these parameters often causes a decrease in the other monitored parameters. Therefore, knowing possible ways of influencing these parameters is important for achieving the optimum result, if possible, in all requirements. A deep understanding of how some technological parameters influence finished surface roughness is still lacking, as well as detailed knowledge of the relationships among some roughness parameters. In response, an experiment entailing machining of planar samples at different orientation angles was carried out to identify the influence of the studied parameters on the transverse roughness of the final surface. A finding was made that the resulting surface roughness is dependent on the cutting edge geometry of the particular ball-end milling tools used, and the achieving of the required surface roughness can be guaranteed by setting the specific lead angles. Furthermore, it was verified that a minimum lead angle limit can be found based on the geometric properties of the specific milling tool, and the relationship between the evaluated roughness parameters Ra and Rz was found as well.

Impellers, which are part of the turbochargers in many transport and agricultural vehicles such as cars, trucks, tractors, boats as well as lawnmowers, are parts where monitoring the efficiency of design and subsequent manufacturing is very important. In order to maximize the efficiency of the compressor stage, many iterations in impeller blade geometry design must be performed to achieve the operating conditions in terms of both performance and strength. Impeller manufacturing is then strongly dependent on the impeller blade geometry design. Manufacturing efficiency varies greatly if the impeller is designed with the blades made up of complex surfaces (requires more machining time) or ruled surfaces (requires less machining time). However, the two impeller geometries have a common element that strongly influences their manufacturing efficiency – the impeller blade fillet radius. The choice of the blade fillet radius value is very limited by the impeller blade geometry design. Therefore, this paper proposes a method to determine the blade fillet radius value in order to achieve an efficient impeller geometry in terms of manufacturing efficiency at the impeller design stage. The method is verified on the example of milling several impeller variants.

This paper deals with a method to optimize tool axis orientations in multi-axis milling toolpaths. The method is based on calculation of the actual cutting diameter and the cutting speed during the toolpath. Subsequently, the NC code is processed by the interpolator with a machine tool kinematic model. The result is a visualization of the actual cutting speed and the real feed-rate on the toolpath. Based on these results, the vectors used to orient the tool axis along the toolpath can be effectively set up in several iterations. The toolpath are optimized to achieve a more constant cutting speedwhich lead to an improvement in surface quality and increase in productivity.

This paper discusses a postprocessor for milling robots connected to additional linear machine axes where toolpath is optimized with respect to variable properties of the robot in its workspace. A toolpath optimization method is proposed based on an experimentally verifiedrobot stiffness model. After postprocessor distribution of the movements between the robot and the linear axes, the collision states during machiningcannot be verified in common CAM. Therefore, a solution enabling simulation of movements after optimization is proposed. The tool center point coordinates are used to control the robot and additional machine axes, while the joint coordinates calculated by inverse kinematic transformation are used to verify the movements.

When milling generally-shaped surfaces with a ball-end milling tool, machined surface roughness and accuracy as well as machining productivity are often monitored. Improving one of these parameters often causes a decrease in the other monitored parameters. Therefore, knowing possible ways of influencing these parameters is important for achieving the optimum result, if possible, in all requirements. A deep understanding of how some technological parameters influence finished surface roughness is still lacking, as well as detailed knowledge of the relationships among some roughness parameters. In response, an experiment entailing machining of planar samples at different orientation angles was carried out to identify the influence of the studied parameters on the transverse roughness of the final surface. A finding was made, that the resulting surface roughness is dependent on the cutting edge geometry of the particular ball-end milling tools used and the achieving of the required surface roughness can be guaranteed by setting the specific lead angles. Furthermore, it was verified that a minimum lead angle limit can be found based on the geometric properties of the specific milling tool, and the relationship between the evaluated roughness parameters Ra and Rz was found as well.

This article focuses on the issue of controlling cutting conditions in point milling strategies in order to reduce machining time. Using cutting tools with a circular cutting edge during point milling strategies of complex shape parts the actual contact point between the tool and the workpiece continuously changes. According to this fact the cutting speed also changes continuously and the required cutting speed is not achieved along the toolpath. Therefore, a solution to control the spindle speed has been developed to achieve the constant value of cutting speed and consequently provide a solution to control the feed-rate in order to maintain the constant value of feed per tooth. Application of this optimization technique has been demonstrated by means of a real machining test. The machined surface quality improvement and machining time savings were proven.

The article focuses on the issue of generating points of the toolpath for multi-axis machining. In multi-axis machining, it is possible to control the toolpath using the coordinate transformations of tool center point (TCP) in the control system, or these transformations in the control system are not available and it is necessary to use the transformations in the postprocessor. However, without the use of TCP, the required toolpath tolerance is not respected. Therefore, an algorithm has been proposed in the postprocessor that dynamically generates new toolpath points so as to maintain the required tolerance and to ensure manufacturing accuracy. This algorithm has been verified by implementation in the postprocessor and generation of NC programs for machining of impeller blades. By the postprocessor recalculated tool path meets the required tolerance.