CNC machining is the most up-to-date method of computer numerical control machining. Because of this, the milling machines used to machine a block of material into a component are automated and controlled by a computer. The absence of a mold lowers the cost and time of production while also allowing for the production of similar components from the appropriate material. As a result, it has been the method of choice for unit productions, such as visual and functional testing.
A Brief History of CNC Machining
CNC machining is based on a machining process that was first established in the 18th Century and is still in use today. Rather than handcrafted procedures, the first "turning the machine with a metal frame" was created in 1751, marking the beginning of a lengthy succession of machines aimed at creating more accurate actions mechanically than are feasible with handcrafted methods. This marked the beginning of the industrialization process in the United States.
However, it was not until the Cold War that the issue of the rise of automation was brought up again. At the time, the business Parsons Works was tasked by the United States Navy with increasing the productivity of their helicopter blade production line. The axes of the machines used to manufacture these blades were then motorized by John T. Parsons. Working with IBM, he investigated the feasibility of operating these devices through the use of a computer. This was the beginning point for the computer-controlled numerically controlled machining process.
In 1952, Richard Kegg, in cooperation with the Massachusetts Institute of Technology (MIT), created the Cincinnati Milacron Hydrotel, which was the world's first CNC milling machine. His first patent for a “Motor Controlled Apparatus for Positioning Machine Tool” was submitted in 1958, five years after his first. This marked the beginning of the commercialization of this technology.
CNC machining is defined as follows:
Plastic CNC machining is characterized by the fact that the machining function is controlled by a program that controls the motions of tools on the block to be machined. While milling, it specifies the axis of rotation of the milling cutter, and during turning, it defines the axis of rotation of the component. Fully automated and computer-controlled, the milling machine has three or five axes and can cut a variety of materials.
The 3D file that is input into the computer specifies the path that the milling cutter will take in order to cut the required portion from the block. In order to accommodate small-scale manufacturing (one to ten pieces), this approach is classified as a "subtractive" method, which means it is both quick and affordable.
As a result, because the economies of scale are so minimal, this approach is not suggested for medium or large series production. Because the parts are similar and made of the appropriate material, it is well suited for small-scale manufacturing of up to 10 pieces for visual and functional testing purposes. A variety of finishes are also available.