Changing Speeds - Grizzly G7947 Manual

Changing Speeds

The belts in the head of the drill press must be
rearranged to change speeds. A chart under the
belt cover shows the belt positions needed to
make the drill press run at the desired speed.
To change speeds:
1. UNPLUG THE DRILL PRESS!
2. Loosen the belt tension lock knobs (shown in
Figure 26) on both sides of the headstock,
so the motor is free to move.
Figure 26. Loosening lock knob (both sides).
3.
Rotate the belt tension lever clockwise, as
shown in Figure 27, to take tension off the
V-belts.
Figure 27. Using the belt tension lever.
-28-
4.
Locate the desired speed on the speed chart
under the belt cover and move the V-belts
to the desired V-grooves on the motor, idler,
and spindle pulleys.
For Example: As indicated in the speed chart
for 670 RPM (Figure 28), a belt combination
of A-1.2-2 creates 670 RPM.
• The "A-1" refers to the belt position between
the spindle pulley and the idler pulley.
• The "2-2" refers to the belt position between
the motor pulley and the idler pulley.
1 RPM 210
Note: Both belts may have to be removed
D 4 4
C 3 before certain speed changes can be made. 3
B 2 2
A 1 1
BELT:A-1.4-4
5 RPM 630
D 4 4
C 3 3
B 2 2
A 1 1
BELT:B-2.3-3
RPM 1650
D 4 4
C 3 3
B 2 2
A 1 1
Figure 28. Pulley combination for 670 RPM for
BELT:B-2.1-1
5.
Rotate the belt tension lever until the belts
are tight. Tighten both lock knobs.
6. Close the cover before plugging in the
machine.
G7947/G7948 12 Speed Floor Drill Press
2 RPM 310
D 4
C 3
B 2
A 1
BELT:B-2.4-4
6 RPM 670
D 4
C 3
B 2
A 1
BELT:A-1.2-2
RPM 2050
10
D 4
C 3
B 2
A 1
example.
BELT:D-4.2-2
3 RPM
4 D 4
3 C 3
2 B 2
1 A 1
BELT:A-1.3-3
7 RPM
4 D 4
3 C 3
2 B 2
1 A 1
BELT:D-4.3-3
RPM
11
4 D 4
3 C 3
2 B 2
1 A 1
BELT:C-3.1-1
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