District IX - 2006/05

160 MODEL AVIATION
IF YOU GO BACK and take a look at the
District IX March column, you’ll notice that I
snuck in a few words and a picture of my
Slow Stick camera set-up with corn walker
John Wells. Little did I know this would set
off a flurry of innovative improvements using
an FMA Co-Pilot by club member Mark
Dennis who writes the following about his
what I coined Slow Stick on Steroids.
“This is a standard GWS Slow Stick that I
use for aerial photography. Ready-to-fly it
weighs roughly 17 ounces without the camera
and 24 ounces with it. Because of the extra
weight, I made a few modifications. I
powered it with an E-Flite Park 480 1020Kv
brushless outrunner motor turning an APC 11
x 5.5 E Propeller.
“I use a Castle Creations Phoenix 25-speed
controller and typically a two-cell 1,500 mAh
Li-Poly battery. On windy days and when I
have the camera mounted I will put in a threecell
pack just to have the extra thrust. (Yes,
it’ll go straight up at half throttle without the
camera mounted with a three-cell pack.)
“The motor can handle a larger propeller,
but it would draw more amperage than the
battery is rated for. This motor is way too
much for this airplane and I am on the
lookout for a slightly smaller one—maybe an
E-Flite Park 400 outrunner—but since I had it
sitting on the shelf doing nothing, the price
was right.
“Other modifications necessary to handle
the extra load include a landing gear
strengthened by adding an additional strut
between the legs near the top and larger pins
to hold the larger rubber bands that hold the
wings on. I made these pegs out of 1-inch
pieces of 1/4-inch dowel with a hole drilled in
them to go over the existing pins and a small
screw from the top holding the other end.
“Additional modifications are a couple of
binder clips to hold the wing on for general
no-wind flying and new 2 mm Coroplast tail
surfaces. The original ones got destroyed
trying to fly in 18-20 mph winds. (I knew I
was in trouble when the rudder folded flat
against the horizontal stabilizer, but I got it
down without doing any more damage. It was
the tumbling weed maneuver the airplane did
before I got to it that did the damage.)
Electronic goodies installed on the Slow Stick.
Tail feathers on Mark’s Slow Stick.
“As you explained in your March column,
we use these airplanes to find downed models
in the corn, but I noticed that with a fixedmount
camera, every time the aircraft pitched
or banked we would lose sight of the field
below. So I thought that it would be great if I
could devise a mount that would keep the
camera aimed at the ground no matter what
the airplane did (within reason).
“I already had an FMA Co-Pilot sitting
around looking for a useful purpose and
thought that if it can keep an airplane straight
and level, it should be able to do the same
with a little camera. All I had to do was make
the Co-Pilot fly the camera instead of the
airplane. Mounting the Co-Pilot pickup
sensor and the camera on the same piece of
wood should keep the camera flying straight
and level.
Here’s a close-up of Mark’s camera mounting.
“The Co-Pilot is designed to control two
channels—ailerons or rudder and elevator—
so I used one servo to counteract the pitch of
the airplane and another to counteract the
roll. To keep it light, I mounted one servo to
the piece of wood that holds the camera and
mounted that servo the control arm of
another. (You should look at the pictures;
this could be confusing to explain.) That
way they provide movement at 90° from
each other.
“In a typical Co-Pilot installation, you
plug the lead from the Co-Pilot master unit
into your receiver channel and then plug the
servo into the Co-Pilot master unit. Since
it’s not going to fly the airplane I couldn’t
do that, but I still needed 4.8-volt power for
the Co-Pilot master unit and a centering
pulse to tell the servos to stay in the middle
of their throw.
“Another kink in the plan is that as part
of the calibration procedure you must move
the servos with the transmitter. These
problems were easily solved because the
GWS Slow Stick only uses the aileron and
elevator channels to control the airplane (as
well as a throttle channel), and since I am
using a five-channel receiver, that left my
rudder channel open to provide the power
and centering pulse.
“I connected both Co-Pilot channels into
a ‘Y’ and plugged my two servos into the
Co-Pilot master unit. All that was left was to
make sure that the camera tilted toward the
ground when the airplane pitches and rolls.
The Co-Pilot unit has reversing switches
built into it, so if a servo moves the wrong
direction you switch it on the Co-Pilot.
“This means that the battery eliminator
circuit on your speed controller has the load
of two more servos. The camera and
transmitter need 4.8 volts to power them, so
they could be powered off of the receiver,
but I thought it would be too large a load on
my speed controller. I use a separate battery
for the camera. (It’s not shown in the
pictures, but it’s a small receiver battery
pack.)
“I wanted to be able to easily remove the
camera from my airplane, so I mounted
everything—the camera, the video
transmitter, the camera battery, the Co-Pilot
master unit, its level sensor and its arming
switch—on one stick. This required that my
airplane be balanced so the camera could be
mounted directly on my CG. This is easily
accomplished on the Slow Stick by sliding
the wing and servos around on the stick until
you get it where you want.”
Mark Dennis and his Slow Stick on Steriods.
So there you have it! If you have any
questions about Mark’s Slow Stick, you can
contact him at [email protected]. This
continues to prove Dave Platt’s point about
modelers being the smartest 10% of the
folks in the world! If these items are of
interest to you, please let me know and most
especially, send me your innovation article!
That’s it for this month. Until next month,
have fun and keep in touch!
District IX
Mark Smith, District IX Vice President; [email protected]
Colorado, Kansas, Nebraska, North Dakota, South Dakota, Wyoming