Gatan 656, Руководство пользователя, Страница: 33 / 49

Performance Check
Dimple Grinder User’s Guide 23
• Adjusting zero stop.
5.1 Arm Pivot Friction
To achieve an accurate response of the measuring system, the friction in the
Platform pivots must be very low.
To check arm pivot friction
1. Lift the Platform off the Micrometer Drive.
2. Disconnect the two wires leading to the Platform.
Temporarily secure them to the Platform with tape.
3. With the tip of a finger, support the Platform at about 20° above hori-
zontal.
Caution: Take care not to drop the Platform.
4. Adjust the balance of the Platform with the Counterweight until the
Platform is exactly balanced at this position.
Adjustment of the counterweight by ±2 g should cause the Platform to gen-
tly fall towards the horizontal or rise to about 60°.
Note: This is not the zeroing of the Counterweight scale.
5.2 Zero Counterweight Scale
The load scale is friction coupled to the Counterweight and is free to rotate and
slide. To set the zero of the load scale, account is taken of the spring tension in
the Dial Indicator stylus and the weight of the grinding wheel.
Note: Ensure that the Dial Indicator has been zeroed
,
a grinding wheel is
mounted to the axle, and the Platform is down.
To zero Counterweight scale
1. Disconnect the two wires leading to the Platform.
Temporarily secure them to the Platform with tape.
2. Screw the Counterweight in fully until it stops.
3. Rotate and slide the black load scale to align its zero to the zero on the
Counterweight.
4. Raise the Platform off the Micrometer Drive.
Support the Platform at approximately 30° above horizontal.