Back to CNC Basics — The Automation
The basic hardware for CNC machines is almost identical to manual machines. The physical process involves any number of cutting tools, clamps, and axes to remove material from a raw part to create a new shape. The physical aspects of the machine were covered in our last blog, The Hardware, and we now have a look back to CNC basics of automation. Understanding how machines communicate is just as important in the client education process to ensure manufacturer and client communicate just as well. CNC stands for Computer Numerical Control. This means the movements of the machine respond to coded language. Here’s a look at how that works from start to finish in CNC machining.
Design
CAD — Computer Aided Drafting established its roots in the 1960s to use vectors and graphics to visualize a design concept in 2D or 3D on a computer screen. In the machining world, this meant the trial-and-error method of establishing the best angles for cutting and material holding could be visualized to translate more effectively on the shop floor. The next step for machining was adding the CAM operating system.
External Communication
CAM — Computer-Aided Manufacturing measures points and angles on those three-dimensional drawings produced on the CAD system to determine the cutting path of the CNC machine. It converts distance, angles, and speed into coding language to be received by the machine. This information used to be manually entered into the CNC machine (and still can be). Both G Codes and M Codes provide the general machine instructions and specific tool operations to guide the machining process. This single step changed the accuracy and consistency of machine shop manufacturing creating repetitive patterns that operate without much human interaction.
Post Processor — This final step is required to ensure the computer language, or code, of the CAM system, speaks to your CNC machine. Each manufacturer uses different codes, so conversion is a necessary final step. Have a deeper look at this external communication in a previous blog.
Internal Communication
MCU — The Machine Control Unit is the brain of the CNC machine that translates code into the movement of the cutting tools and their supporting arms. It has a CPU processor, like a computer, to run all aspects of the machine. The CAD/CAM system provides the preliminary templates, but it is the MCU that puts it into action.
Driving System — Powerful motors are required to run CNC machines. These mechanical motors provide the automated movement of the various working parts to complete the coded instructions for an operation. They dictate the speed and direction in a precise fashion to provide quality cuts with reduced operation time.
