M-238
ActiveDrive™
Dc motor Ordering Information DC motor drives offer severaladvantages, such as high dynamics, high torque at low
rotational speed, low heat and low vibration. The ActiveDrive™ design,developed by PI, features a
high-efficiency PWM (pulsewidth modulation)
servo amplifier mounted side-by-
side with the DC-Motor and
offers several advantages:
M-238.5PG Heavy-Duty DC-Mike Actuator, 400 N, 50 mm, ActiveDrive™ M-238.5PL* Direct
Metrology LinearEncoder to Compensate
Mechanical Play
Heavy-Duty DC-Mike Actuator, 400 N, 50 mm, ActiveDrive™,
Direct-Metrology Encoder* Ask for availability in your region The M-238.5PL model isequipped with a non-contact,
optical, linear encoder (direct
metrology) with an output
resolution of 0.1 µm. Because
the encoder measures the actu-
al position of the non-rotating
actuator tip, drive-train errors
like backlash and elastic defor-
mations are eliminated. A
lower-cost version with a ro-tary encoder is available as
model number M-238.5PG. Increased efficiency, by
eliminating power losses
between the amplifier and
motor Ballscrews for High Speed,Precision and Lifetime Reduced cost of ownership
and improved reliability,
because no external driver
is required The precision-ground ball-screw is maintenance-free andpreloaded to eliminate mecha-nical play. Its significantly re-
duced friction, compared to Non-Rotating Tip Compared to conventionalrotating-tip
micrometer drives,
the non-rotating-tip design
offers several advantages: Elimination of PWM amplifi-
er noise radiation, by
mounting the amplifier and
motor together in a single,
electrically shielded case
M-238.5PL Heavy-Duty Mike actuator (with CD for size comparison) High Load Capacity to 400 N conventional
leadscrews, allows Travel Range 50 mm for higher velocity, lower
power consumption and longer
lifetime. Limit and Reference Switches Resolution to 0.1 µm For the protection of yourequipment, non-contact Hall-
effect limit and reference
switches are installed. The
direction-sensing reference
switch supports advanced
automation applications with
high precision. Max. Velocity 30 mm/s Preloaded Frictionless Ball Screw Optional 0.1 µm Direct-Metrology Linear Encoder forExceptional Precision Elimination of torque-
induced positioning errors MTBF >20,000 h Vacuum-Compatible Versions Available for 10
-6 hPa Elimination of sinusoidal
motion errors The M-238 is a high-load, high-precision actuator providing
linear motion up to 50 mm, a
load capacity to 400 N and high
velocity to 30 mm/s. It consists
of a low-friction, heavy-duty
ballscrew, driven by a closed-
loop, ActiveDrive™ DC-Motor
with gearbox. The M-238 is therefore well suited for high duty-cycle operation in
industrial environments. An
optional linear encoder pro-
vides exceptional accuracy and
repeatability. Elimination of wear at the
contact point Elimination of tip-angle
dependent wobbleThe lateral guiding of the tipwithstands lateral forces of up
to 100 N.
Application Examples Quality assurance testing Testing equipment Precision machining Astronomy Flexible automation Metrology
M-238 dimensions in mm © PI 1998-2006.Subject to change without notice. This data sheet is superseded by any newrelease. The newest release is available for download at www.pi.ws. R1 06/08/24.0 7a-5