Chapter 5: Maintenance 23 of 37
5-4 Sharpening the Knives
Under normal operating use, the cutting edge of the knives will eventually become dulled,
resulting in reduced cutting efficiency. The blunt knives may either be re-ground to restore
the cutting edge, or replaced with new knives when regrinding is not possible.
When sharpening, it is not harmful to allow a few small nicks to remain in the cutting edge.
Grinding the cutting edge until perfectly clean can sometimes be wasteful.
5-5 Adjusting Belt Tension
For continuous reliable operation of the granulator, it is important that the belt tension is
correct. Correct tension reduces wear on rotor and motor bearings and keeps belt slip to a
minimum. Figure 2 below gives the recommended force to deflect each belt by an amount
equal to the belt span divided by 64. A gauge is available through the sales department to
measure the deflection and force. Use the following procedure to adjust the belt tension:
1. Turn off the granulator at the main isolator switch and remove fuses.
2. Remove the cover to gain access to the belts.
3. Turn the adjusting screw on the motor slide base to tension the belts as required
4. Re-tighten the screws, making sure the pulleys are in correct alignment.
5. Replace the covers.
