CNC essays

CNC essays CNC was developed in the late 1940s- early 1950s fuelled by the war effort by machine tool builders. It was used to produce complex machined parts more accurately without human intervention or variability. CNC machines used to be associated with high volume production due to the time involved in machine programming, however new computer technologies along with software advances allow easy programming of CNC machines for low production parts. This report will discuss the operation of CNC systems, the advantages of CNC production, training requirements and their ability to link to CAD systems. CNC machines are basically a computerised machinist that cuts away material away from a standard sized piece of material until the desired product is achieved. A CNC machine uses digital information from a computer to move motors and other positioning systems in order to guide a spindle over raw material. The computer translates design instructions on how the tool must move to create a shape. It uses mathematics and co-ordinate systems to understand and process information on what to move, to where and how fast. A basic CNC machine is able to move in three controlled directions at once. These directions are usually named the x, y and z axis. X is the movement from front to back, Y is the movement from left to right and Z is the vertical spindle up/ down movement. 2.5, 4 and 5 axis machining can also be mentioned. 2.5 axis machining is where the machine tool can cut in all three directions, but cannot cut diagonally when moving down. Usually this is caused by either using a two-dimensional CAD program or it is too difficult a program for the standard controls. 4-axis machining is when a rotating tool holder is able to spin the piece while the piece is being machined. The main reason for this is to eliminate ridge lines that will exist when doing three axis machining as well as reducing the amount of times a piece must be turned. The 5th axis ...