PACKAGE CONTENTS:
1. FMA Direct G100 Piezo Gyro. (See TABLE 1 below for system compatibility)
2. Owner's Manual.
TABLE 1 RECEIVER COMPATIBILITY SERVO COMPATIBILITY
G100 Model #: ACE AIR FUT HITEC JR ACE AIR FUT HITEC JR
G100A 9NO! YES NO! NO! NO!
G100F 99YES NO! YES YES YES
G100J 99NO! NO! NO! YES YES
G100FJ 9999YES NO! YES YES YES
PREPARATION:
•INSTALLATION, RECEIVER AND SERVO CONNECTION
1. The G100 is several times more sensitive than standard motor gyros in terms of
responsiveness. To realize this improved sensitivity in your model, FMA Direct
recommends the use of a high quality, ball bearing servo with fast response. A good
candidate is the FMA Direct model S700 servo. In addition, linkages between the
servo and the control surfaces must have absolutely zero slop. Replace any ball links
or horns that show indications of slop or fatigue. Care must be taken when installing
the gyro to isolate the electronics from vibration as much as possible. The G100
should be installed with servo tape that is a minimum of 1/16" thick, 1/8" is preferred.
The gyro mounting surfaces should be extremely rigid - mounting the gyro to a floppy
object will cause reduced sensitivity or could cause failure of the product due to
excess vibration. Never mount the gyro near any sources of heat such as the engine
or the exhaust. An excellent location for mounting the gyro would be under the
canopy next to the radio gear.
2. IMPORTANT: The top of the G100 is labeled "INSTALL THIS SIDE UP!". Care must
be taken to install the gyro in accordance with this label. Failure to do so will prevent
the gyro from operating. The sensitive axis of the gyro runs parallel to the face of the
gyro (the side containing the color portion of the case label). The gyro will detect
rotation on any axis parallel to the sensitive axis. When mounting the gyro in a
helicopter to stabilize the yaw axis, the sensitive axis must be seen as cutting straight
through the main rotor blades of the helicopter.
3. When hooking up the gyro to your servo and to your receiver, use TABLE 1 to check
equipment compatibility. Note that it is possible to interface JR or Hitec servos with
Futaba style channel leads. Be sure that the Brown or Black leads of each of the
connectors are aligned to one another. Model G100FJ will allow for the maximum
possibilities of interfacing the gyro to different equipment types. You may mix and
match Futaba and JR servos, but neither may be used in combination with Airtronics
servos as the voltage polarity is incompatible and a short circuit will be produced
should the two be interfaced.
4. Connect the OUT lead to the servo, the IN lead to the desired channel on the receiver
and, if desired, the AUX lead to an auxiliary channel on the receiver.
•BENCH TESTING THE GYRO
Referring to FIGURE 1, set the program mode dip switches as shown. The POT/RMT switch
should be closer to POT and the REV/NRM
switch should be closer to NRM. Use a
small screw driver to change the settings on
the dip switches if necessary. Bench test
the gyro by turning on the transmitter and the
receiver at this time. After 15 seconds, the
servo connected to the gyro will center. In
normal operation, the model must be
absolutely stationary for 5 seconds every
time the receiver is powered up. If this
procedure is not followed, trim changes will
result from flight to flight. Move the model
about the sensitive axis (or control axis).
The servo should move as the model is
rotated.
If no movement is obtained:
a) re-verify that the gyro is in "trim pot gain" mode (explained in detail later) by adjusting
the dip switches as shown in FIGURE 1.
b) turn the gain control trim pot to maximum sensitivity (fully clockwise).
If still no movement occurs, check wiring and battery voltage. If still no movement occurs,
contact FMA Direct customer service.
If movement occurs, move the model about the other axis. You may notice some movement
in the servo but it should be substantially less than when moved about the sensitive axis.
•SETTING THE DIRECTION
Once you are satisfied that the gyro is operational, the correction direction must be set. With
the radio on, move the model sharply about the control axis. Notice the movement in the
control surface or tail rotor. The direction of the control surface should counteract the
direction of rotation. If it does not, change the setting of the program dip switch marked
REV/NRM. This setting is extremely important as failure to set the direction switch will
result in loss of control of your aircraft. If you are unsure about how to determine this
setting, please talk to someone who can help you.
MODES OF OPERATION:
•TRIM POT GAIN MODE: Trim pot gain is useful if several gyros are on a model or an
auxiliary channel is not available. When using trim pot gain, the gain select dip switch must
be in the POT position. The gyro's gain can now be controlled by adjusting the gain control
trim pot. Turning the pot clockwise causes the gyro to be more sensitive. The AUX input has
no effect when in this mode of operation and may be disconnected.
•REMOTE GAIN MODE: Remote gain mode is used whenever gain control is to be applied
remotely from the transmitter. When using remote gain, the gain select dip switch must be in
the RMT position. The gain control trim pot will be defeated in remote gain mode.
•STICK PRIORITY: Stick priority operation is easily established using a computer radio. A
standard rate gyro at hover keeps the tail from swinging by applying negative feedback. The
problem is when the pilot desires to spin the tail, the gyro senses this and tries to compensate
by applying opposite tail rotor, thus canceling the pilot's command. The result is a slow rate
of rotation about the axis. With a stick priority gyro, the gyro's effect is reduced when the pilot
commands a turn, hence, forcing "stick priority". With a stick priority gyro, a helicopter can be
set up to spin as fast as the pilot wants while still retaining 100% stability at hover. It is
important to note at this time, that stick priority is not recommended for the beginning
helicopter pilot because it makes the aircraft overly sensitive to stick motion.
Setting Up Stick Priority: To set up your transmitter for stick priority, perform the following:
a) Make sure that the G100 is programmed for Remote Gain operation by setting the
POT/RMT dip switch to RMT setting.
b) Set up a mix so that as the stick is moved off center, the gain is reduced.
c) Make the rudder channel the master and the gain channel the slave.
d) Mix +100% for right rudder and -100% for left rudder.
e) Power up the radio and move the model about the control axis and notice the gyro
sensitivity.
f) Continue moving the model about the control axis while at the same time adding
rudder inputs via the transmitter stick. You should notice a reduction in gyro sensitivity
as the stick approaches the limits in either direction.
g) If an opposite condition occurs (an increase in gyro sensitivity at stick limits), reverse
the mixing percentages. That is, mix -100% for right rudder and +100% for left rudder.
h) You may wish to adjust the mix percentages to tailor performance to your specific
requirements. The mixing percentages determine how "fast" the gain is reduced while
the gain control knob or switch on the transmitter determines the total amount of gain.
GAIN
AUX
IN
OUT
RMTNRM
POT
REV
LEADS
MADE IN
U.S.A. BY
ARCAMAX
GAIN CONTROL TRIM POT
PROGRAM MODE DIP SWITCHES
1. POT/REMOTE
2. REVERSE/NORMAL
3 LEADS
FUNCTION
MARKED ON
CASE LABEL
FIGURE 1
