Browse Topic: Milling
As the aerospace industry moves toward determinate assembly and ever-tighter manufacturing tolerances, there is a need for automated, high-precision milling, trimming and drilling equipment that is specialized for aerospace applications. Precision countersinking is a common requirement for aircraft parts, but this is not a process that typical general-purpose milling machines are able to accommodate without the use of specialty tools such as depth-stop tool holders. To meet this need, Electroimpact has designed a 5-axis milling machine with high-speed clamping capability for countersink depth control. A custom trunnion and head with a quill and an additional clamp axis provide clamping functionality similar in speed and precision to a riveting machine, while maintaining the accuracy and features of a conventional machining center. An additional focus on design for pre-compensation accuracy has allowed the system to achieve post-compensation path and positioning tolerances that are
In the metal-cutting process, the condition of the cutting tool is critical. The tool condition is one of the factors that impact the surface finish. Monitoring the tool’s condition is necessary to ensure the quality of the end result and productivity. Because vibration signals have a strong relationship with tool state, vibration signals were captured in this investigation while milling mild steel specimens with carbide inserts in a vertical milling machine. Four tool conditions were considered in this study, namely, a good tool (G), a tool with nominal flank wear (FW), tool flaking on the rake face (FL), and tool breakage (B). Histogram features were extracted from the captured vibration signal. J48 algorithm is used to select relevant features, which are then fed into Support Vector Machine (SVM) and K-Nearest neighbourhood (KNN) algorithms. SVM and KNN classification abilities are compared. SVM classifies the tool condition with 88.75% accuracy, whereas KNN achieved the
This specification covers the equipment and process requirements for forming or straightening metal parts using Ultrasonically Activated Needle Peening
Innovators at NASA Johnson Space Center have developed a cost-effective method to create fabric-based circuits and antennas by combining conventional embroidery with automated milling. The technology allows for higher surface conductivity, improved impedance control, expanded design and application potential, and greater choice of materials for optimized performance
During aircraft wing assembly, machined fiberglass shims are often used between mating parts to compensate for inherent geometric variability due to manufacturing. At present, fiberglass shims for large aerospace structures, such as shims attached to wing ribs, are manufactured either manually or by precision machining, both of which pose a challenge due to tight tolerance requirements and wide geometric variations in the aircraft structures. Relative to articulated arm industrial robots, gantry-style computer numerical control (CNC) machines are costly, consume large footprints, and are inflexible in the application. Therefore, industrial robots are viewed as potential candidates to replace these gantry systems to facilitate metrology, shim machining, and permanent joining of aircraft structure, with all these processes taking place in the assembly process step. However, the accuracy of articulated arm robots is limited by errors in kinematic calibration, gear backlash, joint
Due to the chemical stability and durability of industrial polymers, plastic waste does not easily degrade in landfills and is often burned, which produces carbon dioxide and other hazardous gases. In order to stop the growing flood of polymer waste and reduce carbon dioxide emissions, plastics have to be recycled or converted into new value-added products
In this developing world, the need for lightweight and high strength materials is increasing in various industries. As a result of the above, the importance of natural fiber is also increasing to satisfy the industrial need. In manufacturing industries in order to assembly the engineering components the drilling is one of the important operations. The main objective of this research is to determine the mechanical properties and drilling efficiency of natural fiber composite. Sisal/flax as a natural fiber, the copper foil of thickness 0.025mm as structural reinforcement and epoxy resin as a matrix was used for making composite. The hand layup technique was used for the fabrication of the composite. Two different types of the composite were fabricated such as C1 (Sisal and flax fiber, embedded with punched copper foil (Ø5mm), 20mm apart and 90° to each other) and C2 (Sisal and flax fiber embedded with a punched copper foil of (Ø4mm), 20mm apart and 45° to each other). After the
In order to take advantage of the machining characteristics of magnesium it is useful to consider recommended tool design and angles. The geometry of the tool can have a large influence on the machining process. Tool geometry can be used to aid with chip flow and clearance, reduce excessive heat generation, reduce tool build up, enable greater feed rates to be employed and improved tool life. This paper presents a new approach for the optimization of Machining parameters on face Milling of ZE41 with multiple responses based on Taughi orthogonal array with VIKOR. Machining tests are carried out 12 mm diameter of insert having 1 flute under dry condition. In this study, Machining parameters namely cutting speed, feed and Depth of Cut and Tool Node radius are optimized with the considerations of multi responses such as surface roughness, Material Removal rate, Tool Wear and Trust Force. A VIKOR grade is obtained from the VIKOR analysis. Based on the VIKOR grade, optimum levels of
This SAE Recommended Practice provides a systematic method for the identification of End Mills. It is intended to assist in the cataloging and supplying of these tools. NOTE 1— Caution must be taken when assigning codes for designation to prevent specifying cutting tools that cannot be physically or economically manufactured. NOTE 2— In particular without limitation, SAE disclaims all responsibility for the accuracy or completeness of information contained within this report if the standards of this report are retrieved, combined, or used in connection with any software
Peripheral grinding of the aluminum alloy EN AB-AlSi9Cu3(Fe) using a vitrified silicon carbide grinding wheel was investigated in this article. The effect of grinding parameters, namely, grinding speed, feed and depth of cut, and grinding condition, up-grinding or down-grinding, on resulting forces, grinding energy, and surface roughness were analyzed. A 22 × 32 full factorial design of experiments was performed. The ground surface morphology showed evidence of rubbing and plowing effects, and ductile material removal was the main mechanism. Within the analyzed process window, the minimum value of surface roughness was 0.28 μm. The experimental evaluation highlighted that forces and grinding energy are directly dependent on chip thickness, and this relationship was further explored as a function of depth of cut and feed per grain. Conversely, an inverse dependence was observed in the case of surface roughness. Empirical relationships for a reliable prediction of the grinding force and
The desired milling process with high material removal rate (MRR) and low surface roughness of the product can be achieved only if machining chatter is absent. Incorporating chatter into the optimal selection of the machining parameters leads to a complex problem. Therefore, the approach of selecting conservative intervals for the machining parameters is usually employed instead. In this paper, a practical approach is proposed to specify the optimal machining parameters (depth of cut and spindle speed) in order to maximize MRR and minimize forced vibrations by considering machining chatter. Firstly, the worst-case scenario-based optimization problem in terms of the surface quality is solved to find the critical time at which maximal amplitude vibrations occur. Then, the time dependency of the problem is eliminated. Secondly, the multi-objective optimization is conducted to achieve the Pareto Optimal Front (POF). The Stability Lobe Diagram (SLD) is obtained independently through well
In 3D printing — also known as additive manufacturing — an object is built layer-by-layer, allowing for the creation of structures that would be impossible to manufacture by conventional subtractive methods such as etching or milling
The high demand of efficient large scale machining operations by concurrently decreasing operating time and costs has led to an increasing usage of industrial robots in contrast to large scaled machining centers. The main disadvantage of industrial robots used for machining processes is their poor absolute accuracy, caused by the serial construction, resilience of gearings and sensitivity for temperature changes. Additionally high process forces that occur during machining of CFRP structures in aerospace industry lead to significant path errors due to low structural stiffness of the robot kinematic. These errors cannot be detected by means of motor encoders. That is why calibration processes and internal control laws have no effect on errors caused by elastic deformation. In this research paper an approach for increasing the absolute accuracy of an industrial milling robot with help of a Laser Tracker system during machining tasks will be presented. To measure the position and
Aluminum skin milling is a very challenging process due to the high quality requirements needed in the aeronautic and aerospace industries. Nowadays, on these markets, there are just two technological approaches able to face the manufacturing of this sort of wide thin blanks: chemical and mechanical milling by means of highly complex machines. Both solutions lead to a high investment requirement that affect directly on the application profitability on these industrial sectors. This paper presents a flexible machining system that allows milling skin shaped parts within required tolerances by means of an innovative universal holding fixture combined with an adaptive toolpath development. This flexible holding fixture can be adapted to the required shape and can hold uniformly the whole sheet surface. Besides, the solution includes an implementation that can adapt the machining toolpath by means of the skin thickness online measurement. The integration of these two innovative devices
This Standard defines a machine coordinate system and machine motion nomenclature for numerically controlled machines. This Standard applies to all numerically controlled machines. For the sake of simplicity, the majority of the text of this Standard is written in terms which are applicable to machine tools but it is nevertheless applicable to numerically controlled machines in general
The manufacturing of medical components must meet standards of accuracy, reliability, quality, and traceability that equal and sometimes exceed those required for aerospace and nuclear parts. In addition, global competition and efforts to restrain health care expense create great pressure to maximize productivity and reduce manufacturing costs. Tooling manufacturers are helping medical partmakers meet these challenges with a selection of milling tools custom-engineered for the machining of complex orthopedic replacement components
This document, as referenced in the applicable product specifications in procurement documents, contains: a A catalog of the standard carbon steels, alloy steels (including H-steels), and stainless and heat-resisting steels that are designated by chemical composition, or (for H-steels) by chemical composition and hardenability limits by reference to standard industry documents. b Rules for designating the chemical content of carbon steels, alloy steels, and stainless and heat-resisting steels that are not classified as standard
Third bodies, also termed friction layers, tribofilms or secondary contact patches, are layers of more or less compacted wear debris between pads and rotor of a disc brake. Our approach of assessing the sliding behavior and friction properties induced by third bodies has been: i) structural characterization after AK-master test procedure, ii) sliding simulation of model structures similar to the observed ones but with simpler and well defined compositions, and iii) verification of simulation results by pin-on-disc tests with artificial third bodies showing the same microstructures and compositions as the model structures. The idea was to simulate structure formation during real braking conditions by high energy ball milling of appropriate powder blends. The final outcome of numerous parameter studies was that a third body containing 15 vol% soft ingredients and 0-20 vol % hard ingredients, both distributed homogeneously in a nanocrystalline iron oxide matrix, should be most desirable
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