Automatic compensating cleanup operation

Journal ArticleToday's part geometries are becoming ever more complex and require more accurate tool path to manufacture. Machining process efficiency is also a major consideration for designers as well as manufacturing engineers. Although the current advanced CAD/CAM systems have greatly improved the efficiency and accuracy of machining with the introduction of Numerically Controlled (NC) machining, excessive material may still be left on the finished part due to machining constraints, including the inaccessibility of the designed part geometry with respect the cutter, machine motion constraints like ramp angles, specific cutting patterns, etc. Polishing operations such as grinding and hand finishing are quite time consuming and expensive and may damage the surface of the part or introduce inaccuracies because of human errors. Although most of the existing machining approaches attempt to reduce such excessive restmaterials by modifying NC tool paths, none of them is satisfactory. They can be time consuming, error prone, computationally intensive, too complicated to implement, and limited to certain problem domains. A compensating cleanup tool path will be developed in this research to automatically remove these excessive material from the finish part. This method greatly reduces the burden of hand finishing and polishing and also reduces the error and complexities introduced in manually generating cleanup tool paths in the shop floor. More important, the tool path generated by this method will reduce the machining time and increase tool life compared with optimized tool path which left no excessive material behind

Automated fiber placement composite manufacturing: The mission at MSFC's Productivity Enhancement Complex

Automated fiber placement is a manufacturing process used for producing complex composite structures. It is a notable leap to the state-of-the-art in technology for automated composite manufacturing. The fiber placement capability was established at the Marshall Space Flight Center's (MSFC) Productivity Enhancement Complex in 1992 in collaboration with Thiokol Corporation to provide materials and processes research and development, and to fabricate components for many of the Center's Programs. The Fiber Placement System (FPX) was developed as a distinct solution to problems inherent to other automated composite manufacturing systems. This equipment provides unique capabilities to build composite parts in complex 3-D shapes with concave and other asymmetrical configurations. Components with complex geometries and localized reinforcements usually require labor intensive efforts resulting in expensive, less reproducible components; the fiber placement system has the features necessary to overcome these conditions. The mechanical systems of the equipment have the motion characteristics of a filament winder and the fiber lay-up attributes of a tape laying machine, with the additional capabilities of differential tow payout speeds, compaction and cut-restart to selectively place the correct number of fibers where the design dictates. This capability will produce a repeatable process resulting in lower cost and improved quality and reliability

Mission oriented R and D and the advancement of technology: The impact of NASA contributions, volume 2

NASA contributions to the advancement of major developments in twelve selected fields of technology are presented. The twelve fields of technology discussed are: (1) cryogenics, (2) electrochemical energy conversion and storage, (3) high-temperature ceramics, (4) high-temperature metals (5) integrated circuits, (6) internal gas dynamics (7) materials machining and forming, (8) materials joining, (9) microwave systems, (10) nondestructive testing, (11) simulation, and (12) telemetry. These field were selected on the basis of both NASA and nonaerospace interest and activity

Integrated System for Machining Process Visualization and Analysis in Blade Applications

The manufacturing industry is heading towards a more digitized environment. Sandvik Coromant is therefore developing intelligent tools, as well as software tools for machining applications. The aim for this thesis is to develop the understanding of a specific machining process. This is done through a background study of previously known methods, followed by development of a demonstrator to integrate machining data, and finally a case study to visualize a process. Continuous development of methods and approaches are required to provide efficient manufacturing processes. Simulations of a machining process is a helpful tool to gain knowledge about relationships between process data and the machining results. Verifying the simulation results is a challenge, especially since every applications has its own requirements. Therefore, a case study is performed during this thesis work for the selected application. A demonstrator for an integrated system has been developed using Integrated Feature based Metrology (IFM), which is an internally developed concept for connecting data from different machining stages. Pre-process data (digital models and process plans) is connected to in-process data (feed, speed, cutting forces etc.) as well as post-process data (geometric evaluations of the finished component). Deviations and correlations that can cause machining problems can be detected and analyzed through alignment of these types of data. The developed demonstrator shows that it is possible to connect data from the three machining stages. A case study is included, where three blade machining processes are performed. Blade design, CAM software, machine and control system are unchanged, but the cutting data is altered for the different blades. Axis positions and feed rates are acquired from the machine control system, along with cutting forces, torques and vibrations from external sensors, to illustrate how the behavior changes for different cutting data. Most notably, the feed rate is varying more as its nominal value increases. Future work includes applying the integrated system for machining processes with more than three axes. More case studies should be performed to further verify the functionality of the demonstrator

Manufacturing technologies in mould industry and future challenges

This report is based on the manufacturing technologies actively used in the industry. The mould industry in Portugal is one of the biggest and considered the best in quality of moulds in various types of industries like Automobile, Medical and Aerospace. The State of the art mould manufacturing technologies like conformal cooling in complex parts, multi cavity moulds are taking over the industry standards to a new level of competitiveness in terms of business and quality achievement. The industry in Portugal is very well known for the quality of the moulds and the process fabrication of mould tools. The future is becoming more and more competitive with advancement in lean manufacturing and the enormous advancement in the 3D printers. With more time the advance in these technologies will help the requirement of polymer parts be met with high power and high capability of print quality achievable it is seen to be posing a threat to the mould manufacturers. They are in dire need to update the manufacturing process and to be in touch with the developments of production technologies in the world of polymers to stay in the competitive market for a long time. This report will touch upon the present manufacturing techniques and state of the art technologies that are coming into use in the industry and the challenges this industry will face due to increase in use of 3D printers

Computer Graphics. Volume 2 - an Annotated Bibliography to the NASA-MSFC Digital Computer Graphics Program

Annotated bibliography on digital computer graphic

The Federal Conference on Intelligent Processing Equipment

Research and development projects involving intelligent processing equipment within the following U.S. agencies are addressed: Department of Agriculture, Department of Commerce, Department of Energy, Department of Defense, Environmental Protection Agency, Federal Emergency Management Agency, NASA, National Institutes of Health, and the National Science Foundation

Robots in machining

Robotic machining centers offer diverse advantages: large operation reach with large reorientation capability, and a low cost, to name a few. Many challenges have slowed down the adoption or sometimes inhibited the use of robots for machining tasks. This paper deals with the current usage and status of robots in machining, as well as the necessary modelling and identification for enabling optimization, process planning and process control. Recent research addressing deburring, milling, incremental forming, polishing or thin wall machining is presented. We discuss various processes in which robots need to deal with significant process forces while fulfilling their machining task