Specifications

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3BUS 208 000 R1301194 Replacement Procedures
Carriage Drive Belt
Use these procedures to replace the carriage drive belt. Once this procedure is
completed, perform a scan direction alignment to make certain that the sensor heads
are tracking each other. Refer to Figure 10-3 on page 195. The carriage alignment
in the drive direction may need to be reset. To check the alignment, complete the
“Process Direction Alignment” on page 48.
Note: When replacing a failed belt, it is required that both top and bottom
belts be replaced as a matched set. Replacing both belts at the
same time maintains sensor alignment by eliminating variation
between belts due to wear. In an emergency situation, it is
acceptable to defer replacement of the second belt until the first
scheduled maintenance shutdown.
Equation 10-1 Carriage Drive Belt Equation
1. Disengage the air clutch so that the heads can be separated.
2. Turn off the power to the drive motor.
3. Move the head carriage with the defective belt to the Scanning Platform idler
end column.
4. Release the belt tension by loosening the idler pulley at the Scanning Platform
idler end column.
5. Remove the end of the drive belt which is attached to the idler end of the carriage
assembly.
6. Attach the new belt with strong tape to one end of the old belt which was
removed in the previous step.
7. Go to the drive end of the Scanning Platform and pull the new drive belt through
the structure.
8. Attach the other end of the new belt to the idler end of the carriage assembly.
9. Move the head carriage to the Scanning Platform drive end, and at the same
time, pull the new belt along with it.
10. Disconnect the two belts attached in Step 6. and discard the old belt.
11. Cut the new belt to a length such that when it is attached to the carriage assembly,
the tension can be adequately adjusted using the idler tension adjustments.
12. Attach the remaining loose end of the new belt to the drive end of the carriage
assembly.
13. Move the head with the new drive belt, center them, and engage the air clutch.
14. Tighten the new belt to 125 ± 25 pounds.
Belt Length 2 center - to - center 8.75 in+×=