cnc - the basics
Responsible for converting the rotating motion of the stepper motor into the linear motion along each axis, the Lead Screw is a highly accurate method of positioning and gear reduction which amplifies the torque of each motor.
The most important aspect of any precision CNC machine is it's rigidity. Each axis needs to be able to move in a very precise way with no deviation from the intended track and that's job of the linear rail guides.
Some machines use V Wheels, Round Bar or Rolling Bearings but the most precise and rigid option is the Fully Supported Linear Rail Guide. With a similar principle to car wheel bearings they ensure that even under the strain of rapid cutting and direction changes the line stays true.
Now that you have your guiding and positioning sorted, the next link in the chain connecting hardware to software is the Motion Controller, incorporating the Stepper Motor Drivers and The Microprocessor which receives signals from the host computer or laptop running your CNC software.