12
Installing the rack.
Correct
Too loose
Too tight
Rack to pinion spacing.
Correct.
The driving surfaces of each tooth are 1 to 2mm
apart. Allowing for slight variance in the height
of the rack when the wheels shrink in colder
conditions or where the gate flexes and the rack
is no longer square to the pinion.
Incorrect!
This will cause skipping of teeth at the slightest
resistance to the gate travel, resulting in the
motor control going out of synchronization to
the gate position. The long term damage here
will be stripped teeth.
Incorrect!
This will cause unwanted rolling resistance
especially in colder conditions. Where the wheel
shrinkage will cause the gate to sit heavier on
the pinion or when the rack is no longer square
to the pinion due to gate flex. (False safety
sensing activation)
The following shows a simple method of installing a rack that ensures you achieve the correct fit between the rack and pinion.
Rack resting on
pinion
Rack clamped
to end of gate
Spirit level
•
Begin by double checking you have adjusted the height adjusting bolts so that there is
about 5mm between the gearbox base and the baseplate.
•
Clamp the end of the first length of rack’s end to the closing edge of the gate.
•
Rest the other end of the length on the pinion as shown here.
•
Use a spirit level to ensure the rack remains true.
•
If satisfied with the rack level fasten the first “TEK” screw (supplied) in
the middle of the slot nearest the closing edge of the gate.
