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16
Push in and turn the balance adjustment knob
(5)
to its mid point setting.
Holding the pan bar to steady the platform, disengage the centre lock (see
Locking the plat-
form
).
Release the sliding plate clamp
(14)
and pull out the sliding plate adjustment knob
(2)
until
it engages with the platform drive. Turn the knob to move the sliding plate fore and aft to
achieve horizontal balance.
The horizontal balance is correct when no perceptible tilting force can be felt on the pan bar
with the platform level. Apply the sliding plate clamp
(14)
and push in the adjustment knob
(2)
to its stowed position.
If there is insufficient movement in the sliding plate to achieve balance, reposition the
wedge adaptor (see
Repositioning the wedge adaptor
), refit the load and repeat the hori-
zontal balancing procedure.
The sliding plate is graduated. Make a note of the position to facilitate rebalancing this par-
ticular payload.
Payload weight and Centre of Gravity height adjustment
When fore and aft balance has been achieved, carry out the payload weight and C of G height
adjustment as follows:
Using the pan bar, tilt the platform forward and backward. When correctly balanced, there
should be no perceptible tilting force on the pan bar at any angle of tilt and the head should
remain in any tilt position to which it is set.
If the head tends to fall away when the platform is tilted, set the platform level and push in
and turn the balance adjustment knob
(5)
clockwise to increase the balance setting. If the
head tends to spring back to centre, set the platform level and push in and turn the balance
adjustment knob
(5)
counter-clockwise to decrease the balance setting.
When the payload weight and C of G height adjustment is complete, check that the fore and
aft balance remains satisfactory. Re-adjust the position of the sliding plate if necessary.
After balancing, exercise the head through both axes to confirm that it operates smoothly.
WARNING! Be prepared to prevent the head falling away suddenly. In the
event of the head falling away violently, increase the setting on
the balance adjustment knob
(5)
.
NOTE:
The sliding plate is graduated to facilitate balancing.
If the balance setting of
the payload is known, turn the knob until that setting is reached.
NOTE:
Setting the platform level will facilitate adjusting the balance setting
