FIGURE 44
STEP 17
R
STEP 18
BELT OR CHAIN AIL ASSEMBLY TENSION ADJUSTMENT
Your pre-assembled Belt or Chain Assembly comes from the factory with the tension
adjusted to factory specifications.
There should be no need for adjustment
.
CHECKING TENSION:
Release
trolley from belt or chain connector. The tension nut/washer should be spaced
approximately 1/16" (1.5) from the stationary end-stop arch at the
header end of the rail assembly. See Figure 45.
ADJUST THE TENSION:
Increase
tension by tightening tension nut clockwise.
Decrease
tension by loosening tension nut
counterclockwise.
TO SHORTEN BELT OR CHAIN RAIL ASSEMBLY UP TO 24” (610):
(See exploded
view of rail assemblies on Page 21)
Note: For trained Martin Garage Door Dealers: Consult factory if cut-off is more than 24”
(610) because the position tab must be kept in the proper location.
Loosen
belt or chain tension as much as possible.
Remove
screws from sprocket holder and rail end-stop.
Slide
belt or chain and all rail assembly parts out of rail assembly from header end.
Measure
and cut off excess rail assembly (1” (25) increments only) from header end.
Disassemble
connector assembly to expose free ends of belt or chain.
Use
the same measurement as the excess rail assembly length and cut the same
amount off both free ends of the belt or chain.
Use
rail assembly end-stop as a guide, mark and drill two 3/16" holes on rail
assembly sides for rail assembly end-stop screws.
Fasten
both ends of the belt ribs or the chain links to the connector assembly.
Slide
all rail assembly parts into rail assembly from header end according to
original assembly.
Tension
the belt or chain following STEP 17.
FIGURE 45
HEADER END OF RAIL ASSEMBLY
BELT OR CHAIN
(BELT SHOWN)
T
HTE
HI
O
IG
N
T
S
DIRECTI
N
RAIL END-STOP
WRENCH
VIEW FROM BELOW
IMPROPER TENSION - TOO LOOSE
PROPER TENSION
RAIL END-STOP
RAIL END-STOP
RAIL ASSEMBLY
RAIL ASSEMBLY
TENSION NUT
AND WASHER
TOO MUCH
SPACE
STATIONARY
END-STOP
TENSION NUT
AND WASHER
CORRECT
SPACE IS 1/16”(1.5)
STATIONARY
END-STOP
HEADER END
HEADER END
COPYRIGHT © 2003 MARTIN DOOR
19
