H4378/H4379 Slimline Bench Grinder -13-
NEVER assemble a grinding wheel on the
arbor without paper or fiber discs between
the wheel and the flange. Omitting the discs
can put undue stress on the wheel, causing
it to crack and possibly fall apart.
ALWAYS visually inspect and perform a
“ring test” on a wheel before assembly. DO
NOT use damaged wheels!
Wheel Mounting
The wheel guard assembly must be removed in
order to mount or dismount a grinding wheel. To
do this:
1. Disconnect the grinder from the power
supply!
2. Remove the 3 Phillips head screws and nuts
that go through the outer guard. Take off the
outer guard and the rim guard.
3. Use a wrench on the nut that holds the wheel
on the arbor. Hold the wheel from turning
with your other hand. Note that the wheel on
the left-hand side of the machine is a left-
handed thread, so loosening it will require
turning it clockwise.
4. Remove the outer wheel flange and the
paper disc. Pull the wheel free from the
arbor. There will also be a paper disc and a
wheel flange on the back side of the wheel.
5. Mount the new wheel in the reverse order or
as shown in Figure 3. Always make certain
there is a paper or fiber disc between the
wheel flanges and the wheel itself. Tighten
the nut snugly but DO NOT over-tighten.
Over-tightening can crack the wheel.
6. Re-install the guards and shields.
7. Run a new wheel for at least 1-2 minutes
while standing clear of the line of rotation. If a
wheel does have defects it will generally fail
as soon as it gets up to full speed.
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Figure 3. Wheel mounting order.
Flange
Flange
Nut
Wheel
Paper/Fiber
Disc
Paper/Fiber
Disc