SIG Four-Star 20EP, Instruction Manual, Page: 24 / 26

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88.
The propeller and spinner should NOT be installed on the motor for this initial test - for safety!
a.
Slowly advance the throttle stick on the transmitter. The motor should start turning. If not, your throttle channel needs to be
reversed on the transmitter.
b.
Now make sure the motor shaft is moving in the correct direction. When viewing the fuselage from the rear to the front - as
if you were sitting in the cockpit - the motor shaft should turn clockwise when throttle is applied. If not, you've most likely
got the polarity of the motor-to-esc or esc-to-battery wiring reversed.
Modeler's Tip - When trying to tighten the prop nut, you may find that the spinner backplate keeps slipping against the
motor's prop flange, allowing the propeller to slip out of position. If this happens, remove the prop nut, propeller, and
spinner backplate, and then glue a small disk of coarse sandpaper (50-100 grit) onto the front of the motor's prop flange.
When dry, reassemble the parts and tighten securely.
Control Throws
The maximum distance that a control surface moves when you move the
transmitter stick to full deflection is normally called the "control throw" or "control
travel". Most modern radio systems allow you to adjust the control throw of the
servos directly from the transmitter. This radio feature is usually referred to as
EPA, or end point adjustment. Use this feature to adjust the control movements
for the ailerons, elevator, and rudder of your Four-Star 20. The following control
movements are recommended for your initial test flight. Some pilots may prefer
"snappier" performance. After the intial test flights you can adjust the control
throws to suit yourself and the way you like to fly.
RECOMMENDED
INITIAL CONTROL THROWS
Ailerons: 5/16" up 5/16" down
Elevator: 7/16" up, 7/16" down
Rudder: 7/8" right, 7/8" left
Note: These measurements are always taken at the widest part of the control surface, at their trailing edges.
Balance Your Airplane
Important: An R/C model should always be balanced with everything on board, ready for flight. The flight battery must be
installed in the fuselage, and the propeller and spinner must be mounted in place when balancing the model.
RECOMMENDED BALANCE POINT
2-3/8" (26%) to 2-3/4" (30%)
Behind The Leading Edge Of The Wing
The main wing spar of the Four-Star 20EP is located precisely in the middle of this balance range. This means that the
simplest way to check the balance of your Four-Star 20EP is to pick up the airplane with a fingertip under the each wingtip
at the main spar location. Slowly lift the airplane off the work table and note the attitude of the fuselage. The airplane
should balance on your fingertips in level position - not nose up or nose down. If the nose hangs low, the model is "nose
heavy". If the tail hangs low, this means that the model is "tail heavy". If either of these conditions exists, you must make
adjustments to correct the problem. Never attempt to fly a model that is out of balance! Since the flight battery pack is the
single heaviest component in the airplane, it can be used to adjust almost any tail heavy or nose heavy condition. This is
simply done by moving the battery forwards or backwards inside the airplane.
FLYING YOUR FOUR-STAR 20EP
The Four-Star appeals to R/C fliers of all experience levels, from beginners to expert pilots. Assuming that expert pilots will
not need much guidance, these notes are written for the newcomer.
Pre-Flight
Be sure your flight battery pack is fully charged. Also be sure your transmitter is fully charged. We highly recommend that
you perform a standard range check on your radio system - with and without the motor running. Make sure your propeller
is balanced and has no nicks or cracks - never fly with a faulty propeller! Finally, take a few minutes to give your model a
thorough pre-flight inspection. Make sure everything is secure and tight and operating properly, before attempting to fly the
model. Any problems you have will not magically disappear at the field - they will get worse!