Analysis of a Typical Stub Shaft - Term Paper Example

Title: 353573 - munfture nasser 2 Dated: March 30, 2009 Contents Serial number Subject Page number 1 Introduction 3 2 Analysis and formulation of the machining process and a plan to complete the machining of the component based on CNC machining. 5 3 The resources, such as machine, tool, fixture, and etc for the machining process/operation 7 4 The work holding strategy for the machining process/operation 10 5 The manufacturing parameters 11 6 NC program of CNC machining of the component 13 7 References 15 Introduction: A typical stub shaft comprises of a hollow shaft having a pair of resilient rubber gripping rings which are mounted thereon for keeping the structural arrangements in their perfect form for assisting in the mechanical function as performed by the stub shaft. In the stub shaft, each resilient gripping ring in the structure is mounted between a chuck and a pressure plate. The Pressure bars hold the pressure plates in spaced format but in operative relationship to each other(1). A stub shaft is basically consisting of thirteen parts in the given sequence as a hollow shaft having a through bore, a fixed chuck removable mounted on the said shaft, an outer circumferential portion, first elastomeric gripping ring, a first pressure plate, a sliding chuck, a second elastomeric gripping ring, a second pressure plate, means keying , a thrust, means keying thrust , a rod, force transmitting means, and rotation of the said rod in one direction for the functioning of the stub shaft. The manufacturing of the stub shaft and its allied parts is completed through a set of engineering tasks including the machining process with the utilization of an advanced shape of the numerical machine system(2). The Numerical control is the automation of the machine tools that are functioning with abstractly programmed commands in the encoded shape of a storage medium. The first NC machine was manufactured in the 1940s and 50s, based on the existing engineering tools that were modified to follow points as were fed into the system on the paper tape mechanism. These early machines were the servomechanisms and subsequently were rapidly augmented into the modern computer numerical controlled (CNC) machine tools that have revolutionized the whole design process in the manufacturing sector(3). These CNC machine tools are helpful in the designing and machining process for the manufacturing of the stub shaft with required standards and quality. The modern CNC systems is automated and is using Computer aided designs and Computer aided Manufacturing programs which are also called as CAD/CAM programs. The stub shafts are produced with the use of engineering tools and equipment along with the utilization of technical and human resources to make the product as per ISO certified standards. The following diagram will illustrate the position of the stub shaft as in relation with other functional parts of the allied items. (2) Analysis and formulation of the machining process and a plan to complete the machining of the component based on CNC machining. The machining process for the manufacture of the stub shaft is processed with the help of CNC machining mechanism as through the removal of the extra objects from the bulk as the waste materials. The process is consisting of a set of interconnected and interrelated engineering stages like designing, manufacturing and finishing of the product with the utilization of the machinery, equipment, tools and CNC machining mechanisms for the production of the stub shaft with required quality and standards(4). The machining process is one of the most important material removal methods used during the manufacturing of the stub shaft with the use of ripper cutter .The process is completed with the use of material-working processes in which power-driven machine tools such as lathes, milling, drill presses are used with a sharp cutting tools to mechanically cut the material for achieving the desired geometry of the product. The semi roughing stage is completed with the use of smaller cutter than the roughing process(5). The stub shafts are manufactured through the machining process. Machining is a part of the manufacturing process of almost all metal products especially which are used in the manufacturing of the stub shaft. A person who specializes in the field of machining process is called as a machinist and the place where the process is completed by the experts is called a machine shop. The process is completed with the assistance of technical knowledge of the subject, utilization of the technical skills with the aid of the tools and moulds for the synthesis of the product and the specifications as attained through the use of CNC machines and CAD/CAM programs for making the product as per the requisite details and specifications. Three machining processes are involved in the machining process for the manufacturing of the stub shafts. These are turning stage, drilling stage and milling stage(6). The designs are formulated with the use of numerical machines and CNC with accurate input information and the related data. The data is essential for the functioning of the machine for the production of the desired products for their normal functioning. These programs are recorded in the form of software systems and these systems are programmed in accordance with the design, configuration and specification of the stub shaft. The cutters and welding machines are helpful in the conversion of the raw product into the finished form with the help of CNC machine tools and moulds. The utilization of CNC machines is extremely helpful in the production of the stub shaft with the specific sizes of all the allied parts which are essential for the working of the stub shafts. The application of engineering tools and machines are necessary for the completion of the task. The stub shafts are hollow shafts and are including an outwardly extending shoulder formed thereon which further comprising a thrust bearing mounted on said the hollow shaft(7). The whole apparatus is in contact with said shoulder with provided stop means for holding a fixed chuck against the movement in one direction on the said hollow shaft. All these are manufactured with the help of CNC tools machines along with necessary encoded data for the completion of the machining process. The use of machining process is helpful in making the product in the desired shape with the performance of all the related engineering tasks with requisite standards and specifications. 3) The resources, such as machine, tool, fixture, and etc for the machining process/operation. The machining processes like turning, drilling and milling are supplemented with other allied processes like shaping, planning, boring, sawing and broaching. The resources needed for the completion of all these types of activities are the raw materials, tools, and machines as in the form of CNC machines and the trained manpower for the execution of the engineering works. All these raw materials are processed by the technical personals in a systematic pattern so as to produce(8). Stub shafts are widely used in the sheeting of rolled paper stock for their further processing in the industrial process. Such stub shafts have been used as lightweight bodies which permit them to be used without any special lifting equipment and in this way lowering the operational cost of the whole process. One type of stub shaft utilizes an expanding leaf element in the industrial process and its manufacturing is designed with special features for making them perfect as per their needs. However, this type of stub shaft has an additional number of parts lead in cost enhancement of the product. There is a chance that the existing stub shafts may lead to slipping and these slipping have the potential to increase the damages to the core paper roll. Stub shafts with expandable rubber shafts require numerous parts and require high maintenance cost and are adapted for the use with four inch cores only. These specifications are achieved with the use CNC machines with CAD/CAM programs with necessary input data as in the encoded format. The stub shafts are manufactured with the use of materials like aluminum with an objective in mind to manufacture a stub shaft with a gripping action of the shaft and are controlled from a single point(9). The stub shafts are designed for a desirable length and have core-gripping means of any diameter with low weight. Lathes are the principal machine tool which is used in the turning and milling operations .In the milling process a rotating tool with multiple cutting edges is used for further processing in the manufacturing of the stub shafts. Drilling operations are used for making holes and these processes are completed in the drill presses sections of the engineering departments of the manufacturing units. Three fundamental and important stages in the manufacturing process for the production of the stub shafts and are completed with the assistance of the tools and moulds(10). These stages are interconnected and interrelated with each other and are listed below: a. designing of the moulds, b. mould manufacturing, and c. Component manufacturing The CNC machine tools which have revolutionized the whole designing process for the manufacturing of products like the stub shafts are working as on the basis of numerical and digital data(11). The data is stored in the CNC machine in the encoded form and is used for the designing of the components in highly automated format with the use of computer aided designs (CAD) and computer aided manufacturing (CAM) programs. CNC Machining is a process which is completed through the computer aided numerically controlled machining process. It is a computer tied mechanism to a machine tool that holds varying amounts and styles of metal cutting tools and equipment usually on a tool carousel indexing mechanism(12). It is an efficient, well organized and very precise way of manufacturing quantities of quality metal widgets. It can take three to five hours to set up a job and that cost has to get into the price in some manner to make the process economically viable.  Small lot items are better at the local prototype or manual machine shop. A set of tools which are helpful in the manufacturing process along with CNC machines are as under: 4) The work holding strategy for the machining process/operation: The working of the stub shafts is depending on the perfection in the specification of all the parts of the shafts for the functioning of the major parts in a coordinated mechanism(13). A rod is disposed in stub shaft which is further bored in said hollow shaft. The rod is having a threaded end which engages a threaded bore in the thrust member. The force is the transmitting means which is extending between the opposing surfaces of said first and second pressure plates of the shaft. The rotation of said rod in one direction is essential for the functioning of the stub shaft. The holding strategy is adopted for the functioning of the machining process which is completed with the help of the required tools as to help in the process along with the use of moulds for the purpose of manufacturing of the stub shaft. The moulds are equipped with return edges, sharp corners, and fillets. Vertical Milling machine, Bridge type milling machines and Horizontal milling machine are the tools are which are used for the manufacturing of the stub shaft which helps in the functioning of the product on normal pattern(14). CNC machines tools are required for the quality output as to determine the size of the final product in the shape of the stub shaft. 5. The manufacturing parameters The stub shafts are designed and manufactured with the help of modern machines along with the combination of multiple tools with the requisite specifications. The machines are handled on the basis of CNC arrangement as guided by the CAD/CAM programs and designs. The products are characterized by the moulds as to manufacture in the shape of central circular cross sections with the light weight output(15). The material used for the manufacturing of the stub shaft is made of aluminum .The inner surfaces are spherical in their appearance and these surfaces are produced with the application of CNC techniques and CAD / CAM programs for the finalization of the stub shafts which permits the shaft to grip the roll core equally at all the contact points . The machining Process moves through a series of stages which are recorded in the following order of their workings: 1. Review of the item/blue print to be machined through the machining process, 2. Design of process flow raw material as to be achieved as finished product, 3. Design fixturing of the part to be machined, 4. Write computer program to the power CNC and machine geometry of the part, 5. Schedule CNC machine time lines and time frames 6. Order and review raw materials to be used in the manufacturing process as to produce the product through the machining process, 7. Pre-Process of stock raw material for ensuring the functioning of the system as on normal basis, 8. Set up and offset tools, moulds fixture and CNC machine being employed for the completion of the tasks with the required specifications and standards, 9. Test and run first part for checking the functions as on prototype basis for the start of the designed tasks through the process, 10. Quality Control inspection as per approved standards as for example included in the ISO standards, 11. Run rest of the parts through machining/QA in process inspections for ensuring the quality and production, 12. Part finishing for example through the grinding, burr removal, plating and allied activities, 13. Final Inspection of the product and 14. Part Shipment if required for the sale of the product in the market. The CNC Machining process has the following benefits 1. Low cost of the production. Once set up, the machines will repeat their works very accurately and require minimal machinist level intervention for their designed works. 2. High part to part accuracy and consistency in the products as in their finished forms. 3. Fast, consistent and continuous working of the machines to achieve finished goods. 4. With part fixturing, fast setup and rapid shipment from the completion of the order. 5. Happy Customers with quality output. 6. NC program of CNC machining of the component The Numerical control (NC) program refers to the automation of machine tools which are used with specific commands. These are abstractly encoded on a storage medium for their further usage in the manufacturing process for the manufacture of the stub shafts. These CNC tools have changed the whole designing process with the use of CAD/ CAM programming. These early machines are supplemented with the use of analog and digital computers for the creation of modern computer numerical controlled (CNC) machine tools. The Machining program for making the stub shaft will be offered in the form of a number of separate segments and these segments will facilitate to the technical personals to complete their related technical works with professional commitment and confidence(16). There are three segments as the understanding of the basic Machining Operations, advanced machining stage and its utilization for the delivery of the task in perfect manner and finally the use of basic welding operations for the completion of the whole task for the preparation of stub shaft in a satisfactory manner. Four types of cutters are used in the process as Ripper cutter, End mill, Slot drill and Ball nosed Slot drill in the process. The manufacturing process needs special attention for the designing, manufacturing, and utilisation for the product for the promotion of the product in the market as per the standards of the International Standards Organization (ISO) which are helpful in getting the desired products through turning, drilling, boring and milling processes with specific designs for the manufacturing of the desired products as in the shape of stub shafts. A method of correcting a machining program with numerical control device during an execution of the machining program will also be utilized through the executing a machining program with a program check, effecting single block stop mechanism at the portion in the machining program at the point where an error is discovered in the program ,the execution of the machining program in reverse order mechanism to a predetermined block shape and correcting the machining program for the normal function of the whole process . The whole process moved in systematic and coordinated fashion as to achieve the product in the shape of stub shafts for their functioning in the normal industrial process with the use of the product that is the stub shafts. As a result all the stakeholders are benefited from the normal working of the product on win-win basis. References: 1. Billington, David P. (1996). The Innovators: The Engineering Pioneers Who Made America Modern. Wiley; New Ed edition. ISBN 0-471-14026-0. 2. Lord, Charles R. (2000-08-15). Guide to Information Sources in Engineering. Libraries Unlimited. doi:10.1336/1563086999. ISBN 1-563-08699-9.  3. Groover, Mikell P. (2007). "Theory of Metal Machining". Fundamentals of Modern Manufacturing (3rd Ed). John Wiley & Sons, Inc. pp. 491–504. ISBN 0471744859 4. Herrin, Golden E. "Industry Honors The Inventor Of NC", Modern Machine Shop, 12 January 1998. 5. Holland, Max (1989). When the Machine Stopped. Boston: Harvard Business School Press. ISBN 978-0-87584-208-0. 6. Krull, F.N. "The origin of computer graphics within General Motors", Annals of the History of Computing, IEEE, Volume 16 Issue 3, (Fall 1994) pp. 40. 7. Noble, David F. (1984), Forces of production: a social history of industrial automation, New York: Knopf, LCCN 83-048867, ISBN 978-0-394-51262-4. 8. Pease, William. "An Automatic Machine Tool", Scientific American, September 1952, pp. 101-115. 9. Reintjes, J. Francis. "Numerical Control: Making a New Technology", Oxford University Press, 1991. 10. Ross, Douglas. "Origins of the APT language for automatically programmed tools", ACM SIGPLAN Notices, Volume 13 Issue 8 (August 1978), pp. 61-99. 11. Siegel, Arnold. "Automatic Programming of Numerically Controlled Machine Tools", Control Engineering, Volume 3 Issue 10 (October 1956), pp. 65-70. 12. Vasilash, Gary. "Man of Our Age", Automotive Design & Production. 13. Weisberg, David. "The Engineering Design Revolution". 14. Wildes, Karl L., and Lindgren, Nilo A. "A Century of Electrical Engineering and Computer Science at MIT", MIT Press, 1985, ISBN 0-262-23119-0. 15. William Makely, "Numbers Take Control: NC Machines", Cutting Tool Engineering, Volume 57 Number 8 (August 2005) 16. Heinrich Arnold, "The recent history of the machine tool industry and the effects of technological change", LMU, November 2001 Read More