Gatan 656, User Manual, Page: 15 / 49

Description
Dimple Grinder User’s Guide 5
3.4 Specimen Rotation Axis
The grinding wheel rotation axis (horizontal) is exactly orthogonal to and inter-
sects the specimen rotation axis(vertical). Producing a good dimpled specimen
requires the point of contact between specimen and grinding wheel to be on the
specimen rotation axis directly below the intersection of the two axes. Precise
alignment of the grinding wheel assembly with the specimen ensures that the
grinding wheel is within the plane of the specimen rotation axis and hence con-
tacts the specimen at the correct point.
Figure 3 Grinding wheel rotation axis.
The correct configuration is determined by the appropriate wheel diameter and
specimen mount assembly. If the diameter of the wheel is too large or too small,
the wheel tilts and its rotation axis moves away from the horizontal, which
causes the contact point to move away from the vertical specimen rotation axis
(see Figure 4).
3.5 Wheel Types
There are two types of wheels available with the Dimple Grinder:
• Grinding wheels
• Polishing wheels
Specimen
Specimen
mount
Centering
ring
Specimen
rotation
axis
Grinding
wheel
rotation
axis
Grinding
wheel
Motion of
pivoted platform