Error modelling–based machining sequence optimization of a pocketed beam milling: part A, end supported beam

This paper, on the basis of error modelling, proved the optimal pocket machining sequences of a simply end supported pocketed beam using mathematic induction method. The optimal pocket machining sequence with the minimum pocket floor height error is the machining from both ends to the middle and the optimal sequence is not unique because of the symmetric supports about the central plane; meanwhile, the optimal pocket machining sequence with the minimum wall position error is the machining from the fixed end to the free end and the optimal machining sequence is unique. A beam of Al7075 (744 mm in length, 172 mm in width, and 100 in thickness ) with 9 pockets was used to demonstrate the optimal sequences. One of the optimal sequence with minimum floor height error was used in pocketing (roughing), and the maximum distortion was 0.693 mm in the middle and the maximum floor height error appeared on both sides rather than the middle, which were 0.477 mm and 0.388 mm, and part growth produced maximum wall position error was 0.719 mm. On the same part, further demonstrated the optimal sequence with minimum wall position error in finishing (with 1 mm dimension in stock for all surfaces) and the wall position errors were fully removed. The pocketed beam machining is a typical and representative case and the results and conclusion can be extended to pocketed plate/board machining and even surfacing.

Investigation of Cutting Force in Screw Cutting by Three Axis Controlling Helical Interpolate With a Wireless Communication Tool Holder System

In recent years, the movement of machine tools including 5-axis control machining centers (5 MC) and turning centers has progressed to enable machining at high speeds and high degrees of accuracy. The accuracy of simultaneous three-axis movement at very high feed speeds has increased significantly. Specifically, with the development of control technologies for these machine tools featuring simultaneous three-axis control, the accuracy of helical interpolation motion at high feed speed has achieved a sufficient level to perform processes such as screw cutting with a thread mill tool. Boring machining and pocket machining for difficult-to-cut materials are processing methods that employ helical interpolation movements with an endmill tool, and it is becoming a promising technology in light of recent advancements. Therefore, we looked at screw cutting with a thread mill tool and proposed a novel monitoring method to improve the accuracy of machining the screw by deriving the radial force of thread cutting from three components — two forces in the X and Y directions and torque around the Z axis — using a piezoelectric dynamometer. In this study, we also investigated the accuracy of machining the screw when the pilot hole and screw were drilled at the same time as well as the accuracy when the pilot hole is drilled beforehand. In addition, we monitored the cutting data and X-Y feed motions using a wireless holder and CNC information to construct a smart manufacturing method for machining screws using helical interpolation. As a result, the proposed monitoring method is effective at improving the accuracy of machining screws from various work materials using helical interpolation motion of a thread mill tool.

Computer Aided Geometric Modeling of Solutions to the Tasks of Applied Cyclography

In the present paper the solutions based on cyclographic method are considered on the example of two applied tasks: generation of road surface forms and pocket machining process engineering. Geometric structures based on cyclographic mapping of space E3 on plane E2 and the corresponding mathematical models in the form of systems of parametric equations are provided. On the basis of the developed models, analytical solutions to the problems of shaping the surface and linear forms of the studied objects in the areas of road design and surface treatment of mechanical engineering products were obtained. The models develop the authors’ previous research and are aimed at comprehensive solution to the problems of surface form generation in application to the two mentioned tasks.

Development of Direction-Parallel Strategy for Shorting A Tool Path in The Triangular Pocket Machining

The machining strategy is one of the parameters which practically influences the time of the different manufacturing geometric forms. The machining time directly relates to the machining efficiency of the tool paths. In area milling machining, there are two main types of tool path strategies: a direction-parallel milling and contour-parallel milling. Then direction-parallel milling is simple compared with a contour-parallel strategy. This paper proposes a new model of the direction-parallel machining strategy for triangular pockets to reduce the tool path length. The authors develop an analytical model by appending additional the tool path segments to the basis tool path for cutting un-machined area or scallops, which remained along the boundary. To validate its results, the researchers have compared them to the existing model found in the literature. For illustrating the computation of this model, the study includes two numerical examples. The results show that the proposed analytic direction-parallel model can reduce the total length of machining. Thus, it can take a shorter time for milling machining.