Industrial automation and design services companies in Malaysia today use Turnkey Automation Solutions to solve a multitude of engineering tasks. Industrial automation and the control of its tools are provided by Computer Numerical Controls (CNC).
CNC provides fast, precise and reliable manufacturing methods – a requirement that has grown proportionately with the rising complexity of modern industrial fabrication. Even common consumer gadgets such as smartphones and home computers require a level of sophistication to manufacture not seen a few decades ago.
CNC Control Mechanism
CNC machines require programme instructions in order for them to function. These highly –automated instructions for the manufacturing process are made using Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) software. The instructions are then loaded into the CNC machine and governs its control.
The motions of a CNC machine are moved along at least two axis, vertically (Y) and horizontally(X). A tool spindle provides depth of movement called the Z-axis. Movement is provided by Stepper motors or servo motors. Stepper motors function through powerful electromagnets. When a Direct-Current (DC) charge is pulsed the motor’s electromagnets turn on the magnets pull on the gears, moving it.
CNC-controlled machines are very precise and reliable. They are used in a wide variety of industrial automation solutions including welding, laser cutting, friction stir welding, ultrasonic welding, flame and plasma cutting, spinning, bending, gluing, fabric cutting, tape and fiber placement, routing, picking and placing, sawing, hole-punching, pinning, sewing and picking and placing.
These systems can be further categorized into two types: Closed-Loop system and Open-Loop system. A Closed-loop system provides feedback and is used in heavy machinery due to its complexity to keep machines operating at speed, accurately and capable of performing tasks repeatedly without failing such as automated metalworking tasks.
Feedback mechanisms allow a machine to monitor-itself to an extent and provide adjustments automatically. Feedback controls can be electronic or mechanical in nature although electronically controlled feedback systems are quickly becoming more common.
Open-loop systems, which do not make use of any computerized/mechanical feedback, are used in machines that generate less force and operate at lower speed. Open-loop systems are simpler and thus cheaper to maintain and repair. Machines that make use of the open-loop system include washing machines and sewing machines. They rely entirely on human judgement to compensate for any adjustments needed to bring the system back on track.
Types of CNC Machines
Used for cutting different materials which translates programme instructions into precision movement. While many use a standard programming language called G-Code, proprietary machines may use their own code.
Used to cut workpieces that are being rotated. They utilize similar control specifications as CNC Mills and can often read both G-Code and proprietary languages.
3. Plasma Cutters
A cutting tool that utilizes an accelerated jet of super-heated plasma to cut through electrically conductive metals with high melting points which are otherwise extremely tough to manipulate. The nature of plasma cutters have the added benefit of protecting the material being cut from oxidation.
4. Electrical Discharge Machining (EDM)
Also known as spark machining, this tool utilizes electrical discharges to vaporize and mould materials into a desired shape. Includes wire EDM, sinker EDM.
5. Water Jet Cutter
Utilizes a stream of highly pressurized water, or a mixture of water and an abrasive substance, moving a high velocity to cut through surfaces such as granite. Useful in cutting materials sensitive to high temperature. High temperatures can modify the molecular structure of materials and thus their properties.
Tool/Machine Crashing and Problem Resolution
Even with the advent of advanced CNC software utilizing full 3D models which allow for impressive crash prediction accuracy, the operation of machines still need to be observed by a human operator. Crashes occur when a machine moves in a way that can damage it, or causes it to go haywire.
Although a mild crash may not directly damage the machine itself it might damage the product being manufactured. To maintain proper, control Absolute Position Sensors, either in the form of optical encoder strips or disks, are used to help the machine ‘see’ the limits of its movement and thus prevent unwanted range of movements or overloading (see Closed-Loop Feedback system).