Wobble; Figure 6.2-9 - Pitch, Yaw, And Roll Motion Axes; Figure 6.2-10 - Pitch, Yaw And Roll; Figure 6.2-11 - Wobble - Newport ESP6000 User Manual

Yaw
Pitch
Roll
X
Z Y
Figure 6.2-9 — Pitch, Yaw, and Roll Motion Axes
The problem with this definition is that, though correct, it is difficult to
remember. An expanded graphical representation is presented in Figure
6.2-10. Imagine a tiny carriage driven by a giant leadscrew. When the
carriage rolls sideways on the lead screw, we call it a Roll. When it rides
up and down on the lead screw pitch, we call that Pitch. And, when the
carriage deviates left or right from the straight direction (on an imaginary
Y trajectory), we call it Yaw.
Yaw
Pitch
Roll
Screw
Pitch
Figure 6.2-10 — Pitch, Yaw and Roll

6.2.10 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 6.2-11).
Figure 6.2-11 — Wobble
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.
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