Principles of CNC Machine Operations

Question: Describe about the terms for the Principles Of CNC Machine Operations. Answer: Computer Numeric Control Computer Numeric Control (CNC) is the automation of machine tools. These tools are operated through programming and encoding. Automation here replaces the mechanical or manual operations done either by levers, wheels or hand, etc. (Reintjes, Francis, 1991). The major application for the automation of the manual or mechanical tasks is the design of the mechanical products. CNC systems are automated through Computer-Aided Manufacturing (CAM) and Computer-Aided Design (CAD) for the design of the end-to-end component. Principle Of Operation The automation of the mechanical and manual tasks is done, by considering the following principle of operation. Figure: Architecture of CNC machines Any kind of motion is the movement controlled in two dimensions, majorly X and Y axes and sometimes in the third dimension, Z, which is the depth. The tools position has to be driven by a motor, and usually, stepper motor is used as direct drive to ensure that the movements are very accurate and less likely with the step down gears, in series. The conversion of the energy is taken place through the transducer. The forces are kept precise or smaller, as these speeds are not much more. In such cases open loop control is used, to maintain the forces to be smaller (Leweis Kenneth, 1959). However, multiple parameters, like accuracy, reliability and speed are to be controlled, with the help of the closed loop. The closed loop is used for the applications, such as commercial metalworking machines. All these parameters are now electronically controlled, for 100%. CNC Milling Machine the modern CNC milling machines are available with compact designs with the material, titanium, ceramic and many other composite materials. Stone granite is used for the base construction that gives better kinematics, stability and overall quality of the machines. These modern machines are usually vertical mills that consist of spindle that moves along the Z axis, vertically. The end to end design of the component gets automated with the help of the automated CAM / CAD programs (Smid Peter, 2008). They have the tooling applications like, tapping, reaming and drilling and usually these tools are combined in a single cell. The cell is rotated and moved with the help of the AC servo motor for performing the required application. The structural features vary from the conventional system, as it makes use of the computer controlled robots and also sometimes with minor human interventions. Unlike the conventional milling, the CNC milling machine gives the final design, almost perfect to the CAD design. These machines were programmed with paper tape, earlier and now are computerized with the augmentation of the computers, digitally. High speed steel is usually used in cutting tools and tool bits (Boccalini Goldenstein, 2001). Alternatively, cemented carbides are also used. Tool management is done automatically, by the consideration of the specified parameters. Figure: Modern CNC Milling Machine The modern CNC milling machines are effective in swarf management. These machines make use of the ball leadscrews to translate the rotational motion, enforced from the AC servo motors to the accurate and pre-defined linear motion, so that the accurate outputs can be obtained. The modern milling machines enable the rigidity of the product to be within the pre-set strengths, without the deterioration and quality and strength. References Boccalini, M. H. Goldenstein. "Solidification of high speed steels".International Materials, 2001. Encyclopdia Britannica,diesinking, 2011. Smid and Peter,CNC Programming Handbook(3rd ed.), New York, Industrial Press, 2008. Nguyen, et al.,STEP-compliant CNC Systems, Present and Future Directions, Springer, 2009.