A lot of people don’t understand what CNC machines actually are. They also don’t know all the capabilities that CNC machines can perform. So, we decided to provide an informative overview of what these machines actually are and how they work.
What Is A CNC Machine: CNC stands for Computer Numerical Control. These machines are mechanical devices that use computer programming to manipulate machine shop tools in the process of fabricating parts.
Common Types Of CNC Machines:
Milling Machines: The most common CNC machines today are milling machines. The milling machine uses rotary cutting tools to remove unwanted excess material form a stock piece.
Drills: A drill bit spins around and makes contact with a block of stock material producing holes or countersinks.
Lathes: Lathes are basically the opposite of drilling machines. The most common lathes spin the stock material against a drill bit where as drilling spins the drill bit into the material. Lathes make contact with the material by laterally moving a cutting tool until it reaches the spinning material.
Programming Of CNC Machines: The code that is imputed into the CNC machine is written and edited by programmers. Programs using G-code are fed into the CNC machines computer through small keyboards. The programming is then retained in the computer’s memory. Using revised code, newer prompts can be added to pre-existing programs.
How CNC Machines Work: Many times the first step in the CNC process is to generate a computer-aided design (CAD) of the product that will be machined. The CAD process will set the dimensions of said part to facilitate the CNC programmer’s written code. The CNC programmers will now write G-code that will control the speed, feed rate and coordination of the CNC’s tools.
Often times the machining process will require the use of multiple tools. To accommodate this, CNC machines combine tools into cells from which a machine can draw from those cells. Standard machines can run in one or two axes while more advanced machines move in multiple axes “laterally in the x,y axis and vertically in the z axis.” More advanced machines can also run rotationally around one or more axes.
Machines with multiple axes can flip parts automatically to remove excess material that was underneath. This allows the material to be cut form all sides automatically without the CNC operator’s assistance. Once the material goes through a CNC machine cycle, the operator can then extract the part from the machine and start the process all over again with new stock material.
Conclusion: CNC machines are a very automated and precise method in machining stock parts. They come in many sizes with numerous axis combinations to fit the required capabilities for any machine shop. The ability for CNC machines to operate machine tools rapidly makes for a more productive, less labor intensive and profitable endeavor.