AEC Colortronic MSH Series 2039 - Manual (Page 31)

C Series Granulators Maintenance 31 of 53
Rotor Knives
We recommend that the rotor knife screws be replaced with new screws every sixth knife
change to reduce the risk of screw failure due to overstretching. Screws must be replaced
with the type specified in the spare parts list.
Caution! Rotor knives should be changed one seat at a time to prevent rotor from
being rotated in an out-of-balance condition.
1. Access the cutting chamber as directed in Section 3-6 on page 16.
2. Loosen and remove the rotor knife screws with a 30 mm socket mounted on a breaker
bar. Make sure you have solid footing while you apply the breaking force.
Note: These screws are tightened to a torque of 640 Nm (472 lbs./ft.), so make sure
you have the proper breaker bar. We suggest a four foot long (1.2 m) bar with a
3/4” (19 mm) drive.
3. Lift the half-knife off of the rotor and repeat with the second half.
4. Remove the rotor locking pin, turn the rotor to bring the next knives into position for
removal, and insert the locking pin to hold the rotor in position.
5. Repeat steps 2 through 4 for each of the remaining knives.
6. Thoroughly clean the knife seats with a stone or other non-marring tool, and wipe the
screws with a lightly oiled cloth. Do not leave an oil film on the screws, as
lubrication can adversely affect the stress on a screw installed to a fixed torque value.
7. Set back the bed knives to clear the rotor knives so that the rotor can revolve freely.
8. Place each half-knife onto the rotor with the chamfered edge facing into the knife
seat, making sure that the backside of the knife is sitting squarely against the back of
the knife seat on the rotor.
9. Lightly tighten the screws and check that a 0.04 mm (0.0015”) feeler gauge will not
pass between the back of the knife and the knife seat. Tap the knife gently with a
rawhide hammer if necessary to close the gap.
10. Tighten the screws evenly and torque the screws to 640 Nm (472 lbs./ft.)
11. Re-check the gap between the back of the knife and the knife seat. If necessary,
readjust the knife.
12. Remove the rotor locking pin, turn the rotor to bring the next knives into position,
and insert the locking pin to hold the rotor in position.
13. Repeat steps 8 through 12 for each of the remaining knives.
14. Adjust the clearance between the bed knives and rotor knives. (See “Bed Knives” on
page 32.)