Design for Manufacturing: geometric manufacturability evaluation for 5-axis milling

Author(s):  
Niechen Chen ◽  
Matthew C. Frank

Abstract The geometric manufacturability of a part design is an important decision factor for various manufacturing applications and is especially critical for the machining process. In machining, the geometric manufacturability is primarily determined by the geometric accessibility, which has a direct impact on decisions such as setup planning, tool selection, tool orientation selection/adjustment, and the tool path strategies. These planning decisions can have significant impact on cycle time and cost. Thus, it can be justified that geometric manufacturability is one of the essential product design aspects that must be evaluated for machining processes. Being able to evaluate the geometric manufacturability will not only provide a part design metric but also offer a new approach for manufacturing process planning and optimization. This research proposes a new method for determining the geometric manufacturability of a part designed for 5-axis milling. In this work, the part design is input as polygon mesh boundary represented models, the 3D tool geometry is sampled to line segments, the 3D geometric accessibility of the part design is calculated, and a new metric for 5-axis milling manufacturability evaluation is developed. Case studies on complex mechanical component design examples are conducted to validate the method.

Author(s):  
Jami J. Shah ◽  
David W.-C. Hsiao

Abstract The work reported here is part of a larger project aimed at developing a system for concurrent design and manufacturing. One of the manufacturing applications is manufacturability evaluation performed on design models based on features. The model is not restricted to a limited set of predefined features, but can contain user-defined features that the application program, such as the Manufacturability Evaluator, has no prior knowledge of. A methodolgy was developed whereby the manufacturability evaluator could understand design features from a manufacturing viewpoint and automonously generate feasible machining process sequences for undocumented features. This requires that the system decompose design features into some generic fundamental terms and compare this representation to the capabilities of common machining operations. Therefore, the system needs deeper knowledge about machining processes than that afforded by production rules. In our method, undocumented features are partially evaluated to derive the faces intersecting at concave edges. An algorithm is developed to organize these faces into manufacturing features. The meta knowledge base captures the fundamental characteristics of a machining process by its elementary producible volume and the limitations of tool motions. This representation enables the manufactuability evaluator to create alternative machining sequences for undocumented features.


Author(s):  
Khorssand Haghpassand

Abstract The five-axis constrained and optimal orientation planning is formulated as a design optimization problem that incorporates the process machine’s kinematic constraints with the workpiece and tool geometry, to obtain a constrained setup orientation which exploits the maximum capabilities of existing machines. This work will introduce this problem, and will obtain the setup orientation for two different types of rotation structures, i.e., tool rotation and table rotation in O(N) time. Further, the obtained constrained setup orientation, will be augmented to incorporate the workpiece surface magnitude, along with different machine rotation structures, to obtain an optimal setup orientation for different machine rotation structures. The drilling process is also introduced and formulated as additional constraints to the optimization problem. The primary application of the introduced algorithms, is the machining process, where, they can efficiently reduce the number of tool motions and surface finishing processes. However, the solution is very suitable for many manufacturing applications, such as inspection, assembly, robotics, painting, welding, aerospace, electronic surface mount technology, and etc.


Author(s):  
Thomas McLeay ◽  
Michael S Turner ◽  
Keith Worden

The most common machining processes of turning, drilling, milling and grinding concern the removal of material from a workpiece using a cutting tool. The performance of machining processes depends on a number of key method parameters, including cutting tool, workpiece material, machine configuration, fixturing, cutting parameters and tool path trajectory. The large number of possible configurations can make it difficult to implement fault detection systems without having to train the system to a particular method or fault type. The research of this article applies a novel method to detect the changing state of a process over time in order to detect faulty machining conditions such as worn tools and cutting depth changes. Unlike studies in the previous literature in this domain, an unsupervised learning method is used, so that the method can be applied in production to unfamiliar processes or fault conditions. In the case presented, novelty detection is applied to a multivariate sensor feature data set obtained from a milling process. Sensor modalities include acoustic emission, vibration and spindle power and time and frequency domain features are employed. The Mahalanobis squared-distance is used to measure discordancy of each new data point, and values that exceed a principled novelty threshold are categorised as fault conditions.


Author(s):  
János Farkas ◽  
Etele Csanády ◽  
Levente Csóka

A number of equations are available for predicting the output of machining processes. These equations are most commonly used for the prediction of surface roughness after tooling. Surface roughness can be influenced by many factors, including cutting parameters, tool geometry and environmental factors such as the coolant used. It is difficult to create a universally applicable equation for all machining because of the variations in different materials' behaviours (e.g. metal, wood, plastic, composite, ceramic). There are also many differences between the various types of machining process such as the machining tools, rotational or translational movements, cutting speeds, cutting methods, etc. The large number of parameters required would make such an equation unusable, and difficult to apply quickly. The goal is thus to create a simple formulation with three or four inputs to predict the final surface roughness of the machined part within adequate tolerances. The two main equations used for this purpose are the Bauer and Brammertz formulas, both of which need to be optimised for a given material. In this paper, the turning of thermoplastics was investigated, with the aim of tuning the Bauer formula for use with thermoplastics. Eleven different plastics were used to develop a material-dependent surface roughness equation. Only new tooling inserts were used to eliminate the effects of tool wear.


2009 ◽  
Vol 3 (4) ◽  
pp. 445-456 ◽  
Author(s):  
Atsushi Matsubara ◽  
◽  
Soichi Ibaraki

Much research has gone into machining process monitoring and control. This paper reviews monitoring and control schemes of cutting force and torque. Sensors to measure cutting force and torque, as well as their indirect estimation, are reviewed. Feedback control schemes and model-based feedforward scheduling schemes of cutting forces, as well as tool path optimization schemes for cutting force regulation, are reviewed. The authors’ works are also briefly presented.


Author(s):  
Swathi Routhu ◽  
Divya Kanakanala ◽  
Jianzhong Ruan ◽  
Xiaoqing Frank Liu ◽  
Frank Liou

The zigzag and offset path have been the two most popular path patterns for tool movement in machining process. Different from the traditional machining processes, the quality of parts produced by the metal deposition process is much more dependent upon the choice of deposition paths. Due to the nature of the metal deposition processes, various tool path patterns not only change the efficiency but also affect the deposition height, a critical quality for metal deposition process. This paper presents the research conducted on calculating zigzag pattern to improve efficiency by minimizing the idle path. The deposition height is highly dependent on the laser scanning speed. The paper also discussed the deposition offset pattern calculation to reduce the height variation by adjusting the tool-path to achieve a constant scanning speed. The results show the improvement on both efficiency and height.


2020 ◽  
Vol 38 (11A) ◽  
pp. 1593-1601
Author(s):  
Mohammed H. Shaker ◽  
Salah K. Jawad ◽  
Maan A. Tawfiq

This research studied the influence of cutting fluids and cutting parameters on the surface roughness for stainless steel worked by turning machine in dry and wet cutting cases. The work was done with different cutting speeds, and feed rates with a fixed depth of cutting. During the machining process, heat was generated and effects of higher surface roughness of work material. In this study, the effects of some cutting fluids, and dry cutting on surface roughness have been examined in turning of AISI316 stainless steel material. Sodium Lauryl Ether Sulfate (SLES) instead of other soluble oils has been used and compared to dry machining processes. Experiments have been performed at four cutting speeds (60, 95, 155, 240) m/min, feed rates (0.065, 0.08, 0.096, 0.114) mm/rev. and constant depth of cut (0.5) mm. The amount of decrease in Ra after the used suggested mixture arrived at (0.21µm), while Ra exceeded (1µm) in case of soluble oils This means the suggested mixture gave the best results of lubricating properties than other cases.


2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.


Author(s):  
Dina Becker ◽  
Steffen Boley ◽  
Rocco Eisseler ◽  
Thomas Stehle ◽  
Hans-Christian Möhring ◽  
...  

AbstractThis paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.


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