11
built up material in the upper part of the bracket
casting.
2. Take the two keys off of the idler pin bracket,
wipe off, and re-grease.
3. Reverse the above steps to make the machine
ready for reinstallation of the belt according to the
Belt replacement
instructions.
7.3
Installing abrasive discs
1. Disconnect power to the machine to prevent
accidental start-ups.
2. Peel off the old abrasive disc.
3. Clean the drive disc surface using naptha or a
similar nonflammable solvent that will dry film-
free.
4. Pull the protective backing half off the new
abrasive disc.
5. Position the new disc carefully so it is centered
accurately on the drive disc. (See Figure 8.)
6. When accurately centered, remove the rest of the
protective backing and press the abrasive disc
firmly against the drive disc so complete
adhesive contact is made.
7. Reconnect the power to the machine.
Figure 8: Installing new abrasive disc
7.4
Replacing the v-belt
1. Disconnect power to the machine to prevent
accidental start-ups.
2. Remove the belt guard (Figure 9) and disc table.
3. Remove the table tilt lock knob (Figure 10).
4. Loosen the four motor bolts so the motor can
slide on its plate.
Figure 9: Removing belt guard
Figure 10: Disc table lock knob
5. Remove the belt from the motor pulley.
6. Remove three of the base mounting bolts, then
loosen the fourth bolt slightly. This allows you to
rotate the machine on the machine base (See
Figure 11).
7. Remove the two bolts, underneath the machine
casting, that secure the disc guard to the casting
(See Figure 11).
Summary of Contents for J-420
Page 21: ...21 11 2 1 Model J 4300A Belt Sander Assembly Exploded View...
Page 24: ...24 11 3 1 Model J 4400A Disc Sander Assembly Exploded View...
Page 26: ...26 11 4 1 Base Assembly Model J 4300A 1 Phase Exploded View...
Page 28: ...28 11 5 1 Base Assembly Model J 4300A 3 Phase Exploded View...
Page 30: ...30 11 6 1 Base Assembly Model J 4200A 4400A 1 Phase Exploded View...
Page 32: ...32 11 7 1 Base Assembly Model J 4200A 4400A 3 Phase Exploded View...
Page 34: ...34 12 1 Electrical schematic single phase...
Page 35: ...35 12 2 Electrical schematic 3 phase...
Page 36: ...36 427 New Sanford Road LaVergne Tennessee 37086 Phone 800 274 6848 www jettools com...