5
EDH0387En1020 — 09/18
BG Series Goniometric Cradles
3.5
Goniometric Cradle Weights
Weights indicated into the below table are average values for goniometric
cradles with a typical drive unit installed, without any cable.
The weight variation between drive units is not very significant.
4.0 —
Drives and Motors
4.1
Stepper Drive Versions
Stepper motor-driven stages are available in 2 versions:
•
The mini-step drive version (PP and BPP) enables high angular speed up
to 20 °/s. The larger models, BGM120BPP to BGM200BPP, feature a
worm mounted rotary encoder for improved accuracy and repeatability.
The encoder also provides a method for detecting motor stalling, an
important feature for applications with loads or high torques.
The BGS50PP and BGS80PP are not equipped with an encoder. Instead,
position is attained by the number of commanded steps and micro-
steps. The high output torque of the stepper motor, combined with
extensive performance tests, ensures position accuracy as long as the
recommended load and torque are not exceeded. The BGS50PP and
BGS80PP provide very high motion sensitivity with good linearity
between commanded micro-steps and the actual motion of the stage at
a very reasonable price.
•
The full-step version (PE) is equipped with a reduction gear providing
higher torque. This version is only available on the models BGM120 to
BGM200 and is recommended for high inertia payloads and vacuum
applications.
Weight [lb (kg)]
BGS50 1.76 (0.8)
BGS80 4.63 (2.1)
3-meter MSCABLE-3 Cable for BGS80 models 0.66 (0.3)
(M-)BGM120 18.7 (8.5)
(M-)BGM160 39.7 (18.0)
(M-)BGM200 83.8 (38.0)
3-meter MCAB-3 Cable for (M-)BGM models 1.32 (0.6)
