QWhat’s the difference between a stepper and a servo?
AThe basic difference between a stepper and a servo-based system
is the type of motor and how it
is controlled. In a servo-based
system, there is constant signal
feedback from the encoder (or
motor) to the servo drive. This
feedback tells the servo drive
exactly where it is within its move.
The servo is much more power-
ful, has quicker acceleration time
and quicker positioning speed.
A stepper based system runs
on an open loop meaning it
sends out the number of pulses
to the proper axis to get to the
programmed location. Because
of their simplicity, steppers are
less expensive than servos, but
when configured correctly, they
will also produce great cuts on a
QWhat’s better, rack- and-pinion or ball screw?
AThe short answer is that both are good based on which is best suited for
a particular axis or application.
Ball screws are best known for
being smooth and friction-free.
They can be a good choice for
the short axis. Over a long axis
(4-foot) however, a ball screw-driven system can be susceptible
to “screw whip,” which is vibration that worsens the faster a
screw rotates. This is because
CNC router FAQs:
What you need to know