COMPUTER NUMERICAL CONTROL

Computer Numerical Control (CNC)

Computer Numerical Control

Introduction

Computers are everywhere. We find the computer in life-critical systems such as traffic light control systems or the airport control tower. Many of the medical systems, imaging, diagnostic, and treatment, are computer driven. And at any workplace, be it the office or the factory, we find computerized systems: from word processing and accounting, through architectural or printed circuit board (PCB) design or newspaper typesetting, up to computer numerical control (CNC) machine control and material conveyance. Even at home we have computer games and Internet browsing. Our wristwatch, cellular phone, and personal digital assistants (PDAs) all are computers. Our interaction with computers has become a fact of life.

The CNC (computer numerical control in English), until the eighties that were only used for high precision, are now widely available and used in almost every field of mechanics. The technology of CNC machines has covered a bit 'all branches of mechanics, CNC machines are the most common press brakes, punch presses, lathes, milling machines and metal cutting machines (laser, oxyfuel, plasma, water jet, etc.) They represent the evolution of NC machines, because they allow the direct numerical control from an external computer (DNC). (Noble, 2004)

Features

The proper design of structures of machines and tools require analysis of factors such as materials, structures, forces, and weight, manufacturing and performance considerations. The best approach to get the ultimate accuracy of the machines and tools is the use of improved structural rigidity and deflection compensation for the use of special controls, the frame structure used in long time that allows easy access to the work area of the machine, with the advent of numerical control, become practical box-type frame, which has a static stiffness much better, which greatly reduces the need for manual access to the work area, employing a box-like structure with thin walls can provide low weight for a given stiffness, the principle of lightweight design delivers high dynamic stiffness that provides a high natural frequency of the structure by combining a high static strength with reduced weight, instead of using a large mass, this is for the tools and the center numerical control but for the manufacture of the equipment they need to be robust and are fixed to prevent heavy vibration that produce perfect exit as possible, because the vibration causes movement and this is something you do not want to happen.

Origins

Origin program (OP): this is the origin point of the program from which the movements of the machine are programmed.

Origin Machine (OM): This term is in textbooks of manufacturers of machine tools without providing an answer, or even unfounded. The original machine is a coordinate measure. During initialization of the axis (in the case of sensors relative) to the zero crossing of the rule, the initialization process to force the register value of the current point by the value of the axis in the register P16 (case of a DCN NUM). This value is often not zero, which calls into question the notion ...