User's Manual

22
Figure 44
To test the balance of the vertical axis, perform what
is called the SLED ARC TEST. To perform the SLED
ARC TEST, simply hold the Glidecam HD-PRO by
it’s handle and then grab a hold of the back end of the
HD-PRO’s BASE PLATFORM, then pull the BASE
up and back until the HD-PRO’s CENTRAL POST
is horizontal and motionless (See gure 42) then
gently let go of the BASE PLATFORM and count
how many seconds it takes for the HD-PRO to go
from the horizontal position it was just in (See Figure
43) to the moment it rst passes the vertical.
If the Glidecam HD-PRO is vertically balanced
properly, then it should take about TWO to THREE
seconds for this to happen. (This is called DROP
TIME) Count your seconds with the words “one
thousand one, one thousand two etc for accuracy.
Adjust the amount of COUNTER WEIGHTS used on
the BASE PLATFORM or adjust the length of the
TELESCOPING POST up or down, until it only takes
TWO to THREE seconds for the HD-PRO CENTRAL
POST to rst swing in an arc from horizontal to
vertical.
This photo shows the Glidecam HD-PRO
swinging past the illustrated vertical line. The
HD-PRO will pendulum or swing past this line
during the “SLED ARC TEST”, and the HD-PRO
will swing back and forth over a dozen times if left
to swing, but it is only the time the HD-PRO’s rst
swing in an arc from horizontal to vertical that you
need to analyze. After you have counted the times
it takes for it to go from Horizontal until it passes
vertical once, then simply stop the HD-PRO from
swinging, then either put the HD-PRO down or
make adjustments to perform the test again.
***NOTE: Adding more weight or telescoping
out the base will speed up the DROP TIME.
Removing weight or telescoping the base in
will slow the DROP TIME.
NOTE: The amount of DROP TIME nally set is ultimately up to you to decide. Different
DROP TIMES change the vertical balance, and therefore change the results obtainable
when shooting.
Another way to check for correct vertical balance, known as the ”MOVEMENT TEST”, is to walk
forward with the Glidecam HD-PRO and then stop suddenly. If the HD-PRO BASE PLATFORM
swings or pendulums away from you, or upright vertical position it was just in that moment you
stopped, then you know the HD-PRO is not balanced correctly. Adjust the amount of COUNTER
WEIGHTS used on the BASE PLATFORM or adjust the length of the TELESCOPING POST up
or down until the HD-PRO remains vertical during the “MOVEMENT TEST”.
This “MOVEMENT TEST” also applies to running or turning around quickly with the HD-PRO.
Again if the HD-PRO is balanced properly, then any body movement like running or turning quickly
will not effect the basic upright, vertical position of the HD-PRO. Some practice may be required
to complete the “MOVEMENT TEST” correctly.