Jet IBG-8, Operating Instructions And Parts Manual

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4. Stabilize wheel by holding opposite wheel
firmly, or placing a wood wedge between
wheel and tool rest.
Figure 11: wheel replacement
5. Unscrew arbor nut (D) with a wrench.
Note : Turn the nut on the right-hand wheel
counterclockwise to loosen. Turn the nut on
the left-hand wheel clockwise to loosen.
6. Remove outer flange (E), wheel (F), and inner
flange.
7. Clean flanges. Check the flanges to make sure
they are flat. Wheel flanges that are not flat will
cause the wheel to wobble.
8. Inspect the new grinding wheel and perform a
“ring test”. Do not install a damaged wheel.
9. Install inner flange, wheel (F), outer flange (E)
and nut (D) on the shaft. Tighten nut.
Do not over tighten nut;
this may cause the wheel to crack.
10. Note for IBG-12 model only: The inner flanges
have a larger (1-1/4”) diameter hole than the
outer flanges. Install them in their proper
places.
11. Reinstall guard cover. Adjust spark guards and
tool rests to 1/16" clearance from wheel.
9.4 Wheel balancing
With the grinder unplugged from the power
source , and arbor nuts snugged down, rotate
wheels by hand and observe their motion.
A grinding wheel has proper balance when:
1. The wheel’s outside face spins true and round;
that is, its circumference rotates concentric to
the arbor.
2. There is no side-to-side wobble.
The operator who takes time to patiently perform
needed adjustments will be rewarded by wheels
running true, and accurate grinding of work pieces.
9.4.1 Adjusting concentricity
If the outside face is not rotating concentric to
arbor, try shifting the wheel closer to arbor
centerline before tightening the nut.
Another method of achieving concentricity is the
use of a wheel dresser. “Dressing” is the removal
of the current layer of abrasive to expose a fresh
surface. A wheel dresser is also used to “true” a
wheel; that is, to make the grinding surface parallel
to the tool rest, so the entire wheel face presents
an even surface to the work piece. Proper use of a
wheel dresser will eliminate high spots and result in
concentric rotation about the arbor, as well as
minimize vibration. See
sect. 9.5 .
9.4.2 Correcting side-to-side wobble
The IBG series grinders have large, machined
flanges, making wobble unlikely if a good quality
grinding wheel is used. Should a wheel exhibit
need for adjustment:
1. Loosen nut and rotate the outer flange a little.
Snug the nut and spin the wheel by hand to
check.
2. If wobble still exists, continue repeating step 1,
rotating outer flange incrementally in the same
direction. See Figure 12. Make sure to keep
the wheel in the same position each time.
3. If complete rotation of outer flange has proved
ineffective, remove nut, outer flange, and
wheel (keep wheel in same orientation by
placing a pencil mark on it somewhere for
reference). Then rotate inner flange about 90°
and repeat the above steps for the outer
flange.
4. Continue this combination of flange
movements until the wobble is eliminated.
If required, a shim made of paper or card stock
may be placed between flange and wheel side.
Figure 12: wheel balancing
NOTE: Very slight wobble may still exist at spin-up
and spin-down, but will not affect normal speed
operation.