Kessler MOTION CONTROL: Oracle Controller Full (2.04 SL) - Manual (Page 10)

16 17
You can use the “Flash Mark” screen as a
visual clapper board when you need to sync
footage.
This is useful if you are layering several
recordings on top of one another for
compositing work.
If you hold the Oracle in front of your camera
and press a memory bank button for play
back, you can use the “Flash Mark” screen
flash as your sync point.
It is a good idea to leave a few seconds of no
movement at the front of your recorded move
to allow you time to get the ORACLE out of
frame before the camera move starts.
STEPPER MOTORS
DEMYSTIFIED
Understanding how a stepper motor
works can aid greatly when doing
advanced configurations with the
ORACLE. This section will briefly cover
the basics of a stepper motor and how it
interacts with an ORACLE.
The stepper motors, used in the Kessler
Crane systems, have only 4 variables with
which we are concerned.
ON, OFF, CYCLES,
and POWER.
ON and OFF are just that. The motor is either
on or it is off. The
POWER determines how
much the motor moves when it is in the on
mode.
CYCLES is how many times the on/off
sequence occurs.
So let’s go through a basic setup to explain
further. If we set the motor
ON time to be
.5 seconds and the motor OFF time to also
be .5 seconds, a complete CYCLE of on/
off would take 1 second. If we ran this on/off
cycle 30 times, the entire move would take
30 seconds. The only variable we are missing
in this equation is
POWER.
POWER determines how far the motor will
move when it is on. The lower the power, the
less distance it will travel. The greater the
power, the greater the distance. We liken
this to the difference between walking and
running.
In our sample, we know the motor turns ON
and will move for .5 seconds in each CYCLE.
By adjusting the POWER, we can determine
how far it moves in that half second. If you
want a slow, short move, you would use a
low power. For a faster, long move, a high
power would accomplish this.
The following charts show a generic example
of the difference between a high
POWER
setting and a low POWER setting while
keeping the ON, OFF, and CYCLES variables
constant.
Distance Traveled
18 Cycles at Low power = smaller steps in travel
18 Cycles at High power = bigger steps in travel
The above sample is very basic but it gives
you an idea of what you can do by adjusting
only one variable. In Advanced mode on the
ORACLE, you can individually adjust each
variable (
ON, OFF, CYCLES, POWER) to
create custom moves.
For example, lets say you have a Kessler
Shuttle Pod setup on a 30 foot track and you
want to program the ORACLE so the motor
comes on every 10 minutes and moves the
Pod 1 foot. In this example, we know that
our motor
OFF time should be 10 minutes so
there is a 10 minute gap between each time
the motor turns on and moves the Pod. If we
are moving the Pod 1 foot in each
CYCLE
and our track is 30 feet long, we’ll want to
keep the cycles to less than 30 so we don’t
run out of track.
The only two variables left is ON time and
POWER. These two variables are the only
unknowns in this sample. We’ll need to do
some experimentation here to find the proper
combination of
ON time and POWER that
translates into a 1 foot move on the Pod. In
this example, we can leave the
POWER at
the default of 40 and simply adjust the ON
time until we get 1 foot in travel. Let’s say
that time ends up being 2 seconds for the
sake of this example (this number will vary
depending on your specific setup and motor
being used).
Now we know each variable to create a move
every 10 minutes in 1 foot increments down
a 30 foot track. We will set the motor OFF
time to 10 minutes, the motor ON time to 2
seconds, the POWER defaulted to 40, and
the CYCLES set to 30. When we hit run, the
Pod will move 1 foot and stop. 10 minutes
later, the next cycle will start and the Pod
will move another 1 foot and stop. It will do
this 30 times (cycles) before the move is
complete.
You are not just limited to linear moves like
this. Another real-world example would be
setting up a turn table on an elektraDRIVE
motor where you just want the motor to turn
on and stay on for a certain period of time.
If you wanted your turn table to spin for 10
minutes, you could define a motor
ON time
of 10 minutes at POWER 40 and 1 CYCLE.
This would spin the table for 10 minutes and
then stop (1 cycle).
This may sound complicated all written out
but once you get some practical experience
with the ORACLE, this will be easier to
make sense of. Adjusting the 4 variables
in advanced mode of the ORACLE will
allow you to create just about any move
you can imagine for an endless number of
configurations.