LiftMaster BG770 Industrial-Duty Single Arm Barrier Gate Operator - Manual (Page 10)

10
ARM AND TURNBUCKLE SHAFT ADJUSTMENTS
MODEL BG770 ADJUSTMENTS
1. If necessary, rotate the pulley on the motor by hand until the
crank arm on the gear reducer is perfectly aligned with the
turnbuckle shaft (Figure 9). This is the lowest point of the arm
travel and should be preset in this position at the factory.
2. If the arm is not level, loosen the jam nuts at both ends of the
turnbuckle shaft Insert a screwdriver or other similar tool into
the hole in the shaft. Rotate the shaft either clockwise or
counterclockwise as necessary until the gate arm is in the
desired horizontal position. Retighten jam nuts.
MODEL BG770 TURNBUCKLE SHAFT ALIGNMENT
If necessary, align turnbuckle shaft with center of crank arm for
lowest point of travel of pivot arm (Figure 10).
MODEL BG790 ADJUSTMENTS
1. If necessary, rotate the pulley on the motor by hand until the
upper and lower cranks are in a vertical position (Figure 11).
This is the lowest point of travel and should be preset in this
position at the factory.
2. If the arm is not level, loosen the jam nuts on both the top and
bottom end of the turnbuckle shaft.
3. Rotate the shaft either clockwise or counterclockwise as
necessary until the gate arm is in the desired horizontal
position.
NOTE: While the arm is raising, the upper and lower cranks
should travel toward the side access cover.
I N S T A L L A T I O N
Turn off power BEFORE making ANY adjustments.
CAUTION
Figure 9
Figure 10
Figure 11
Turnbuckle Shaft
Turnbuckle Shaft
Jam Nut
Jam Nut
Pivot Arm
Crank Arm
See Note
Pulley
Pulley
Lower Crank Arm
in Closed Position
Upper Crank Arm
in Closed Position