Newport ESP300 Series, User Manual

Page: 240 / 314

5.2.10 Wobble
This parameter applies only to rotary stages. It represents the
deviation of the axis of rotation during motion. A simple form of
Wobble is a constant one, where the rotating axis generates a circle
(
Figure 5.11 ).
There are two types of loads that are of interest for motion control
applications: static and dynamic loads.
Figure 5.11: Wobble Generates a Circle
A real rotary stage may have a more complex Wobble, where the axis
of rotation follows a complicated trajectory. This type of error is
caused by the imperfections of the stage machining and/or ball
bearings.
5.2.11 Load Capacity
The static Load Capacity represents the amount of load that can be
placed on a stage without damaging or excessively deforming it.
Determining the Load Capacity of a stage for a particular application
is more complicated than it may first appear. The stage orientation
and the distance from the load to the carriage play a significant role.
For a detailed description on how to calculate the static Load
Capacity, please consult the motion control catalog tutorial section.
The dynamic Load Capacity refers to the motor's effort to move the
load. The first parameter to determine is how much load the stage can
push or pull. In some cases the two values could be different due to
internal mechanical construction.
The second type of dynamic Load Capacity refers to the maximum
load that the stage could move with the nominal acceleration. This
parameter is more difficult to specify because it involves defining an
acceptable following error during acceleration.
5-10 Section 5 – Motion Control Tutorial