CNC Control

cnc machine control

What is CNC Controlling

Since we are dealing with machines that do work for us, we need to control those machines somehow. We need to control them for safety reasons as well. If you give a machine improper commands it can easily get out of control and cause harm to you or the part you are machining. We want to give appropriate commands to our machines, at appropriate times so they are not "out of control".

The programming language that these cnc machines use is called GCode G-code has been around since the early 60's. There are a number of variations of G-code, but most are very similar to one another. See the previous section for a sample of G-Code.

We need a computer to chat with our CNC Machine. Our computer will send signals to our CNC machine. In-between our computer and our CNC machine sits a controller. A controller converts commands into signals that are used to control the motion of our machine.

As these signals are sent out of the controller, they go to either stepper or servo motors. This is how we get motion. These motors drive our various axis on our CNC machine. While we are moving our axis, there is generally a cutting tool of some sort removing material. This is the machining process coupled with CNC.

Here is a brief description of the two types of motors generally used in CNC:
Stepper motors:
Simple design
Easy
Generate torque at low rpm
Do not know their position in relation to the program

Servo Motors:
Generate torque at high RPMs
Generally need gearing of some sort to be effective
More sophisticated
Can maintain their relative position, thus, they can be more accurate

Machine Controllers
Controllers generally stand alone near the CNC machine. They act as a translator between your cnc control computer and your machine. Generally, they add quite a bit of cost to a CNC machine as well. Controllers can cost anywhere from $1000-$20,000 or more depending on their sophistication.

CNC Community Site:
If you would like to know more about CNC, head on over to http://www.CNCInformation.com You can join for Free and you get two free CNC ebooks. One is a GCode Quick Guide and the other is the CNC Info Site eBook. You also get access to the Free Video Series...Image to CNC Art when you join the community.