13
8.5
Blade Replacement
A general-use variable-tooth blade is provided with
this band saw.
Choice of blade pitch is governed by thickness of
workpiece: the thinner the workpiece, the more
teeth advised. A minimum of 3 teeth should engage
workpiece at all times. If blade teeth are so far apart
that they straddle the work, severe damage to
workpiece and blade can result.
1) Disconnect the machine from the power source.
2) Raise the bow to the vertical position.
3) Open the rear guard by removing the two (2)
knobs (see Figure 8-8).
4) Remove the red guard from the upper blade
guide by removing two (2) screws.
It is essential that red blade
guard be installed after new blade has been
fitted. Failure to comply may cause serious
injury.
5) Release tension on the blade by turning the
tension
handle
(P,
Figure
8-5)
counterclockwise. Remove blade. (Use gloves
when handling sharp blades).
6) Install the new blade between the blade guide
assemblies and around each wheel. Make sure
blade teeth are pointing in the proper direction.
See Figure 8-6.
Figure 8-6
7) Increase blade tension just enough to hold the
blade on the wheels. Make sure the back of the
blade rests lightly against the shoulder of both
wheels. Twist the blade slightly to allow it to slip
into the guides.
8) Install red blade guard with screws.
9) Tension blade fully (see
sect. 8.8 Blade
Tension.)
10) Place two to three drops of lightweight oil on
blade.
11) Adjust blade guide bearings (see
sect. 8.6
Blade Guide Bearings).
12) Connect machine to power source.
13) Run saw and make sure blade is tracking
properly (
sect 8.9. Blade Tracking.
)
14) Follow blade break-in procedures
(sect. 9.1).
8.6
Blade Guide Bearings
1) Disconnect the machine from the power source.
2) Loosen the bolt (Q, Figure 8-9) and adjust the
assembly so that the rear bearing (R
1
) is
approximately 0.002 to 0.003 inches from the
back of the blade. Also, the inside bearing (R2)
should very lightly contact the blade. Tighten
bolt (Q).
3) Inside bearing (R
2
) is fixed. Outside bearing (R
3
)
rotates on an eccentric shaft. Rotate the nut (S)
with a 14mm wrench to adjust the eccentric
bearing to a clearance of 0.001 inches from the
blade.
4) Repeat above steps for the opposite blade
guide assembly.
Figure 8-7: Blade Guide Setting
8.7
Chip Brush
The wire chip brush must be properly adjusted and
maintained in working condition, otherwise damage
to the blade can occur. Adjust brush so that its
bristles overlap the blade. Replace brush if it
becomes worn or damaged.
8.8
Blade Tension
1) Disconnect the machine from the power source.
2) Open the rear guard by removing the two (2)
knobs (see Figure 8-8). Observe the position of
the blade on the wheel. If blade is not adjacent
to wheel flange, first adjust the blade tracking
according to
sect. 8.9 Blade Tracking.
3) If blade is properly adjacent to wheel flange,
slide blade guide assemblies as far apart as
possible, and tighten in position with knobs (N,
Figure 8-5).
4) Push on the blade to test tension. Finger
pressure should cause approximately 0.004"
deflection. Turn the blade tension handle (P,
Figure 8-5) until proper tension is achieved. For
more precise measurement use a blade tension
gauge (not provided).
5) Return blade guides to operating position.
Summary of Contents for BHVBS-712B
Page 22: ...22 12 1 2 BHVBS 712B Bow Assembly Exploded View...
Page 27: ...27 13 0 Electrical Connections BHVBS 712B...
Page 29: ...29 NOTES...
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