Use and Care Manual

13
10. Press firmly against the full surface of the disc.
The idea here is to be sure the grinding disc
makes full contact with the drive disc and is
laying absolutely flat on the disc surface.
11. Move the wheel guard forward so it covers the
edge of the grinding and drive disc.
12. Adjust the table height to working height.
13. Reconnect power to the machine.
14. Turn the machine "ON" and observe the action
of the disc for possible imbalance. When you
are certain all systems are operating correctly,
grinding operations may resume.
Figure 13 (repeated)
9.2 Removing and replacing motor
and/or drive disc
In the rare event that damage to the drive disc
might require its replacement, or electrical failure
might require motor replacement, the following
procedure can be used. Since motor replacement
requires removal of the drive disc, these
procedures are treated as a single procedure.
Ignore the motor replacement instructions if you
are only servicing the drive disc.
To remove drive disc from motor shaft:
1. Disconnect the grinder from its electrical power
source to prevent accidental start-up and to
allow motor replacement without danger of
electrical shocks.
2. Lower the table to its lowest position. (See
sect. 7.3, Raising and lowering the table.)
3. If you are replacing the metal drive disc,
remove the abrasive disc before proceeding.
(See sect. 9.1)
4. Remove the socket head screw and washer
from the center of the drive disc.
5. Loosen the two socket head set screws which
secure the drive disc hub to the motor shaft.
6. Loosen the four bolts which hold the motor to
the stand.
7. Slide the motor toward the rear of the stand
while pulling the drive disc and hub toward the
front of the stand. This is a combined effort.
The disc and hub can be separated from the
motor shaft only if you perform these two
operations at the same time.
8. Slide the drive disc and hub off of the motor
shaft.
To replace the drive disc:
9. Remove the three bolts and washers which
hold the disc to the hub.
10. Position the new disc on the hub and secure it
with the bolts and washers.
11. Align the support plate keyway with the key on
the motor shaft and slide the hub plate onto
the motor shaft as you also pull the motor
forward on its plate. Do this until the assembly
bottoms out against the shaft.
12. Reinstall and tighten the retaining screw and
washer which screws into the center of the
motor shaft.
13. Tighten the two set screws which secure the
hub to the motor shaft.
To replace the motor:
Note: be certain you have performed all of the
steps above – through step 8 – which remove the
drive disc assembly from the motor. And, BE
CERTAIN YOU HAVE TURNED OFF POWER TO
THE MOTOR AND HAVE LOCKED OUT POWER
TO THE BRANCH ON WHICH YOU WILL BE
WORKING. JET recommends that a licensed
electrician perform all electrical service work for
this grinder.
14. Open the plate on the motor frame where the
electrical service cable enters the motor.
15. Remove the wires from their connectors to free
the cable from the motor. Note and label the
positions of the wires.
16. Remove the four bolts and washers which
secure the motor to the stand.
17. Place the replacement motor on the frame and
secure it loosely with the four bolts and
washers.
18. Open the motor plate to expose the electrical
connections.
19. Connect the switch-to-motor cable to the wire
positions noted in step 15, above, then close
the motor electrical cover plate and tighten the
cover plate screws.
20. Install the drive disc and hub plate as outlined
in steps 11-13, above.
21. Raise the table to its highest position.