Specifications

36
0 400 800 1200 1600 2000
1,000,000,000
100,000,000
10,000,000
1,000,000
100,000
10,000
1,000
Life of Lead Screws
Ball screws = 90% survival
Acme screws = end play exceeds .020"
702 ball screw
705 ball screw
605 ball screw
605 acme screw
Actuator Force (pounds)
Cycles (24 inch extend and retract)
Glossary
Acceleration
The change in velocity as a function of
time.
Axial lash/backlash
The axial free motion between the ball
nut and screw without rotation between
the two components. Backlash can also
occur in gear sets and bearings.
Cantilevered mount
A mount where the actuator is not
supported on both sides. Cantilevered
mounts are not recommended.
Axial load
Load through the axis of the actuator
screw.
Extension rate
The speed at which the actuator extends
or retracts. The extension speed is load
dependent and the actuator must not be
programmed to exceed the load/speed
curve.
Extension tube
The cylinder which extends in and
out of the actuator
Holding brake
Anti-backdriving brake which holds the
position of the ball screw actuator under
tension or compression with the power
off.
Home
A reference position in a motion control
system. Often designated as the zero
position.
Hysteresis
The difference in actuation distance of a
reed switch or Hall Effect switch as it
moves through a magnetic field.
Inertia
A measure of an object’s resistance to
change in velocity.
Lead screw life
Acme screw – the length of travel that
Acme screws complete before end play
exceeds 0.020". Ball screw – the length
of travel that 90% of a group of ball
bearing screws will complete or exceed
before the first evidence of fatigue
develops. See lead screw life chart.
Ambient temperature
The temperature of the air surrounding
the actuator or control.
Backdriving
The load causing the ball screw to
reverse direction with no power applied.
Backlash compensation
Technique of always approaching a point
from the same direction to eliminate the
axial lash in the system.
Ball bearing screw
A lead screw type where the nut does
not directly contact the screw but rather
runs on a recirculating series of ball
bearings generating about 90%
efficiency.
Clevis mount
U-shaped shackle that has ends drilled
to receive a pin or bolt.
Compression load
A load that would tend to compress the
actuator.
Cover tube
The outside tube which covers the
extension tube and screw assembly. The
cover tube also has a channel on three
sides for mounting sensors.
Cycle
One full extension and retraction back to
the starting point.
“D” connector
Either a 9 or 25 pin connector for use
with RS-232 communication. The
connector has a “D” shape to prevent
reversing the connection.
Diode
A solid state one-way switch used
in series with the input devices
when connecting them to the
I/O board
Duty cycle
The ratio of motor “on” time to
total cycle time.
Duty cycle = on time
on time + off time
Eccentric load
Off center load which may cause
binding and shorten actuator lead
screw life.
Encoder
A device which translates mechanical
motion into electrical pulses which can
be counted by a control.
Right
Actuator Axis
Wrong
Axial lash (backlash)
Ball nut
Ball screw