OK so we've talked about HOW a CNC machine works with g-code and what "numerically controlled" is, but just how does the machine work - physically?
In this section I'll try to explain the various parts of a basic CNC machine, and a few of the various CNC machine types there are. There are many options for all of the various parts, and we will cover each topic, but this is just a quick overview of the parts.
The basic parts of a CNC machine are:
- Computer - The computer tells the motors how far to turn, you also need a certain software to interpret the G-Code program and send signals to the Motor Controller
- Motor Controller - The motor controller interfaces with the computer and the motors, and basically takes the small signals from the computer and turns it into bigger signals to drive the motors
- Motors - You need a motor for each axis. Most people (at least in the hobby world) use a "stepper motor" because they can be accurately tuned to turn to an exact position
- Lead Screws - Lead screws are screws attached to the motor via some coupling and when the motor turns, it turns the screw
- Lead Screw Nut - a Lead screw nut would be attached to whatever you wanted to move, say the X Axis, and when the lead screw turns it pushed the nut, essentially pushing the axis
- Linear bearings - a linear bearing, or linear motion, is what the axis' will move on, there will be a whole section on linear bearings and the various types
- Axis - Each axis serves to move the spindle or the table, when the lead screw turns ir pushes the nut that is attached to the axis, so the whole axis moves
- Spindle - the spindle is like a router, and can even be as simple as a router, that is used to actually mill the workpiece
In the next sections we will go over each item in more detail, but the list above are the basic parts that go into every CNC machine.