G-code tells the machine how fast it should go:
M3 S5000 (Turn the spindle on at 5000RPM)
G1 F100 X22 Y33 (Go to X=22 Y=33 at 100IPM or 100mm/min)
The machine will generally obey the G-code unless:
- It is not capable of going that fast or that slow.
- The spindle controller is not accurate enough.
- The user has changed the speed with "override" controls.