JR G550T User manual

Gyro Amp LED Red/Green Mode Indicator
Tail Lock On/Off Switch
Connector
to Gyro Sensor
Rev. Switch
Servo
Connector
Connect to
SV
Gyro Sensor
JR 4735 Standard Analog
JR 8700G Super Servo
or 8417 Digital Servo
Rudder Connector
Connect to RUDD
Rate/Tail Lock
Remote Select
Aux 3 Connector
(white)
Receiver
G550T
ADVANCED TAIL LOCK™GYRO SYSTEM
INSTRUCTIONS
JRPG550T
For Helicopter use only
For use with JR Standard, Super
or Digital Ser vos.
FEATURES
• Advanced Tail Lock: The G550T features both a normal “rate” mode, as well as an
“Advanced tail lock” mode. The advanced taillock mode is designed to provide the
3D pilot with a high-performance heading hold system.
• Rate Mode: The G550T’s design is based from the previous G1000 and G900,
which are known world over for their performance and reliability.
•Servos: The G550T is designed for usewith JR’s Standard Servos as well as
8700G Super or8417 DigitalServos.
• Offset drift canceling: Circuitry for superior neutral stability.
• Remote gain control: Provides remote adjustment of the gain values, as well as
access to rate and tail lock modes.
• Lightweight Piezo sensor w/ dampening: New double action suspension dampen-
ing and lightweight Piezo crystal — total sensor weighs only18 grams!
• Compatible with all JR, Futaba®and other radio systems.
SPECIFICATIONS
Operating Voltage: 4.8V only
Operating Current: 50mA (not including servo)
Dimensions
Gyro Sensor: 32 x 30 x 36 mm
Amplifier: 38 x 19 x 53 mm
Weight
Gyro Sensor: 18 grams
Amplifier: 33 grams
Total Weight: 51 grams (1.8 o.z.)
INTRODUCTION
JR’s new advanced G550T is based on JR’s outstanding G1000 and G900 the
G550T incorporates the same rate gyro technology, while adding the new “advanced
tail lock”heading hold mode. This new “tail lock” mode has been designed to pro-
vide the 3D Helicopter pilot with a heading hold system that will allow the pilot to
push both their flying skills, as wellas their equipment to the limits.
SERVO SELECTION
JR’s G550T can be used in conjunction with JR’s Standard Analog servos 4735,
8700GSuper Servo or 8417 Digital servos. These servos feature an ultra-quick
responseand transit time and are specifically matched to givethe best possible res-
olution when usedwith the G550T.
HELICOPTER TAIL ROTOR SYSTEM
Important: Because of the highly active/aggressive characteristics of this G550T,
heavier-than-normal loads are placed on the tail rotor drive train. Ensure that the
main drive gear system and tail rotor gearbox is in good working order with the
correct gear mesh and unworn teeth. Also be sure it’s properly greased with all
screws secured with Locktite®, etc.
On Miniature Aircraft X-Cellhelicopters, a heavy-duty front tail rotor tune-up kit is
recommended (part # MIN0832). When using theG550T in a JR belt-driven tail
rotor helicopter, such as the Ergo 60 or Vigor, it’s recommended that the optional JR
aluminum tail pulleys be installed for maximum performance (JRP960322 front,
JRP960323 rear). The use of aluminum pulleys will greatly reduce tail belt slippage
as compared to the standard plastic pulleys. It’s recommended that the tail belt be
checked after each flying session. If worn or missing teeth are discovered, replace
the tail belt as needed.
Note: The G550T SHOULD NOT be installed in a modelthat utilizes a “PIANO
WIRE”tail drive system, as failure can occur.
MAXIMIZING THE G550T
Note: The G550T Piezo Gyro’s operational features and functions are very differ-
ent from other types of gyros. The adjustments, including traveladjust, exponential,
dual rates, tail rotor compensation values and gain values will be very different from
your previous normal settings. Do not install the G550T in your helicopter using
your current set up. The capabilities of this gyro are much greater; therefore, the
adjustment values will be different, and you must adjust them correctly to realize the
system’s full potential.
Carefully read this instruction manual and be sure you fully understand and fol-
low each segment before your first flight.
INSTALLATION
When deciding where to mount the gyro sensor, consider the criteria below:
Vibration
Because vibration ismotion, the G550T Gyro senses even minutevibrations and
acts upon them, sending therudder servo an opposing command. For optimum
results, it’s imperative that your helicopter is as vibration-free as possible. All rotat-
ing components (e.g., main gear, head, tail rotor, blades, clutch, etc.) should be in
perfect balance. Equally important, the engine should run smoothly and consistently.
Spending the extra time to ensure that your machine is running perfectly will allow
the gyro gain to be turned up higher, more effectively holding the tail.
Temperature
The Piezo sensor is sensitive to drastic changes in temperature. Note that the
case features a matte chrome finish that is designed to reflect heat. When mounting
the gyro sensing unit, be sure that it’s located away from theengine and exhaust
system so the heat does not transfer to thesensing unit. Also, when subjecting your
helicopter to temperature changes (e.g., going from your warm car to the cold out-
doors), allowthe gyro’stemperature to stabilizefor about 10 minutes before flying.
Installing the Gyro Sensor
Thoroughly clean the bottom of the gyro sensor and the mounting areawith rub-
bing alcohol. Use one layer of the supplied double-sided tape to securelymount the
sensor in position.
Note: Do not use thick foam tape or multiply layers of double-sided tape as is
common practice with other gyros. The G550T’s sensor is vibration/shockmounted
inside itscase via a rubber/air dampening system, and no further vibration isolation
is necessary.
Installing the Amplifier
Using the 1/4” or thicker foam, wrap the amplifierand the receiver together, mak-
ing sure that at least one thickness of foam is between the receiver and amplifier.
Fasten the receiver and amplifier to the radio tray using rubber bands, making sure
they are securely held in place. If space restrictions don’t permit the amplifier and
receiverto be mounted together, wrap them individually in foam and mount each in
a convenient location. Use an optional servo extension lead if necessary.
CONNECTIONS
Step 1: On the gyro amplifier, locate the lead marked “RUDD”. Connect this lead to
the rudder channel in the receiver.
Step 2: On the amplifier, locate the lead marked “AUX 3.” Note that it has a white
connector for identification. When using a JRPCM-10, 10S, 10SX, 10SXF or 10X
radio system, connect this lead to the Aux3-channel in the receiver. For JR 8103
systems, connect this lead to the Aux2-channel.
Note: When using this gyro with other radios, like the JRXP652, the Aux3 lead
must be connected to the appropriate channel — the one you use to alter the gain.
For example, if you want to use the gear switch to alter the gain, plug the Aux 3 lead
into the gear channel and use the travel adjust and sub-trim function to achieve the
desired gain in both switch positions.

Step 3: On the amplifier, locate the SV (Servo) receptacle. Plug the rudder servo into
this receptacle, noting the correct polarity as indicated by the shape of the plug, as
well as the wire color.
Tail Lock™Selection/Connection
The G550T offers several methods to access and use the taillock function.
Note: If you’re using a 6- or 7-channel system, you must install the G550T as
detailed in Option 1.
Quick Start
Option 1 is a quick way to get up and flying with your G550T, as it is the easiest
to set up. If you select the option to have thetail lock mode on, it will not be neces-
sary to use any form of tail rotor compensation, further simplifying the initial setup.
Option 1: Tail Lock Mode or Rate Mode Always On
If you choose to have the G550T function in either tail lock orrate mode only,
simply move the tail lock switch located on the amplifier to the desired position (On
for tail lock, OFFfor rate mode). With this option, it is not necessary to connect the
Black SEL Aux 2 connector. Please note that with this method, it is not possible to
access both the tail lock and rate modes from the transmitter as onlyone Aux chan-
nel is being used.
Option 2: Remote Rate and Tail Lock Mode Access
Connect the black SEL Aux 2 connector from the amplifier to the following chan-
nel on your receiver:
JR PCM 10 series (9 and 10-channelsystems): Gear (Channel 5)
JR XP8103 series (8-channel systems): Gear (Channel5)
This option will allow both the standard rate andtail lock modes of the G550T to
be remotelyselected during flight via the gear switch.
This method will also allow for the use of an optional program mix that will allow
the G550T’s modes to beselected via the Aux 3 gyro gain function. This method will
also enable the G550T’s modes to belinked to the flight mode switch.
INITIAL RADIO SETUP
The G550T Gyro is much more responsive than most standard gyros, and it can
sense and correct for rotation rates at over 720˚ per second. Because of this, the
travel adjust and exponential values can be much different than they are with other
gyros to obtain the optimum feel and rotation rates.
Travel Adjust
Set the rudder’s travel adjustment to maximum right and left. If you’re using a JR
PCM-10/10S/10SX, set the travel adjustment to 150% left and 150% right. These
values will be fine tuned in the Setup and Adjustment section.
Dual Rates
The recommended starting pointsfor dual rates are:
Flight Mode Maneuver Dual Rate V alue
Normal Hovering 60%
Flight Mode1 540 stall turns 100%
Flight Mode 2 Standard aerobatics 60%
Exponential
Because a very large stroke is used (150%), the control sensitivity around neutral
is high. Exponentialis necessary to reduce the sensitivityaround neutral. The rec-
ommended starting points of exponentialare:
Flight Mode Maneuver Exponential Value
Normal Hovering 30%
Flight Mode 1 540 stall turns 40%
Flight Mode 2 Standard aerobatics 40%
Note: After you have gained some experience and flight time, you can alter travel
adjust, dual rate, and exponential valuesto suit your flying style.
SETUP AND ADJUSTMENT
Following is the step-by-step procedure that must be followed to achieve the
highest level of performance from your gyro system.
Step 1: Unhook the tail rotor linkage at the rudder servo and swing the servo arm
out of the way. Lightly grasp the tail rotor pushrod at the servo end and move the
tail rotor throughout its entire stroke. The tail rotor linkage should move through
its full range smoothly with very little friction and no rough spots. Work on the
linkage system until this is achieved.
Step 2: On your transmitter, reset all the rudder trimmers (sub-trim, trim offset,
stunt trim, mechanical trim lever, etc.) to zero or center. Set the throttle/pitch stick
at exactly the hover position (normally 50%). Turn off or zero out both the revolu-
tion mixing (up and down) and the acceleration mixing.
Step 3: Turn on your receiver and allow the helicopter to remain totally motionless
for three seconds. A bright LED light on the amplifier will come on after three sec-
onds, indicating the gyro has digitally stored the zero rotation value.
Step 4: Install the servo arm 90˚ to the tail rotor pushrod (see diagram). You may
find that the splines are slightly offset on your servo, not allowing an exact 90˚
positioning. If so, rotate the
servo arm to another arm
position and try again.
Secure the arm in place with
the screw provided. Attach
the pushrod to the arm at
approximately 16 mm out
from the center. Later, we
will optimize this distance
through flight testing.
Step 5: Be sure the rudder
servo is moving in the cor-
rect direction. A right servo command should move the nose of the helicopter to
the right. (If you’re unsure, seek help from someone with more experience.)
Reverse the servo direction in the transmitter’s programming if necessary.
Step 6: Give a right rudder command and note the direction the rudder servo
moves (clockwise or counterclockwise). Then pick up the helicopter and quickly
rotate the nose to the left. The servo should move in the same direction as it did
when you applied right rudder (clockwise or counterclockwise). If the rudder servo
rotates in the opposite direction, move the reverse switch located on the amplifier
in the opposite direction.
Step 7: With the G550T in tail lock mode (green LED), check to insure that the
servo will remain in the neutral (centered) position. If the servo "creeps" or slowly
moves in either direction, enter the sub trim function of your radio system and add
a sub trim value as needed until the servo will remain in the neutral position, with
no tendency to creep in either direction.
TAIL ROTOR LINKAGE ADJUSTMENT
With the servo arm positioned at 90° degrees to the control rod, adjust the over-
all length of the tail control rod so that the tail pitch mechanism is at the center of its
travellimits. It’s also necessary to insure that the tail rotor blades have the proper
degree of pitch in the neutral position to maintain a stationary hover. Approximately
5° is a good starting point. The final pitch of the tailblades will needto be finetuned
during test flights by adjusting the tail linkage mechanically.
Servo Travel Adjustment
With the G550T in rate mode, adjust the overall left/right travel of the servo
through the travel adjust function of your system so that there is no binding of the
linkage/tail pitch mechanism at full left/right travel.
Note: You will notice that with the travel adjusted, it appears that the rudder stick
only works the servo throughout half its stroke. This is normal! During flight, the
gyro provides feedback to the servo that combines information about its rotation
rate and the gain setting that givesproportional rotation rates throughout the rud-
der’s stick travel.
Important: When properly adjusted, it’s normal for the rudder stickto only affect
the rudder’s position around the center half of its stroke. During flight, the gyro
senses the rotation rate of the helicopter, and the rudder servo works normally
throughout its totalstroke.
RATE/TAIL LOCK MODE SELECTION
Thereare two set up options available when installing the G550T.
Note: While in tail lock mode,
a slight changein the neutral
position of the servo may occur
while the model is in a station-
ary position. In addition, when
the servo is moved to the
extreme left/right position and
released, the servo will slowly
moveback to the neutral posi-
tion.
These movements are com-
pletely normal and are caused
by the Angular Velocity Command Control System of the G550T. These movements
only occur whilethe model is stationary. In flight, these movements do not occur.
OPTION 1: Tail Lock or Rate Mode Always On
(Mandatory with 6-channel systems)
Step 1: Locate the tail lock switch on the gyro amplifier and move to the desired
position (ON for tail lock mode, OFF for ratemode).
Step 2: Turn the radio system ON andconfirm that the G550T is in the desired mode
(red LED: rate mode, green LED: tail lock mode).
Note: If the tail lock mode is selected, make sure that all tail rotor mixing values
in the radio program have been reset to the factory default (0) position.
procede to gyro gain settings.
Rudder Servo
90°
16mm
Control Ball
Attach Control
Ball to Arm
16mm from
Center.
Off/On Rev.
LED Indicator
Red: Rate Mode
Green: Tail Lock Mode
Tail Lock System

OPTION 2: Remote Tail Lock and Rate Mode Access
(Available only with 8 and 10 channel systems)
Step 1: Locate the tail lock switch on the gyro amplifier and move to the ON posi-
tion.
Step 2: Verify that the mode remote select lead from the amplifier is connected to
the desired Aux channel Gear (Channel 5).
TAIL LOCK/ RATE MODE PROGRAMMING
Tail Lock Mode Programming (Option 2)
The programming shown below only applies if Option 2 was selected from the
previous sections. The programming indicated in this section only applies to 8 and
10-channel systems.
If you have selected Option 1 Gyro Gain setting section.
JR 10 Series Systems
Step 1: Access a standard program mix (code 51-54) and assign a mix from Aux 3
(Ch 8) to Gear (Ch 5). This will make Aux3 the master and Gear the slavechannel.
Press “ENTER” and select “NO” for servo hold.
Step 2: Press the “PAGE” key to access the second screen. Select the desired flight
modes for the Tail Lock function to be active by pressing the “SEL” key below each
flight mode box as shown below.
In thisexample, we have selected flight modes 1 and 2 to be in tail lock mode. All
other modes, unless activated, will be set to the standard rate mode.
Note: For proper operation, please check to insure that all tail rotormixing values
have been reset to 0 forthe flight modes that tail lock mode will be used.
Step 3: Press the “PAGE” key again to return to the first screen. Set the mix value
located in the shaded box to - 100 as shown below.
Next, activate the
G550T and while
watching the LED indi-
cator on the amplifier,
movethe flight mode
and throttle hold switch
through their positions
to check that the
G550T is changing to
the desired modes (red for rate, green for tail lock).
If the G550T does not move to the desired modes, check to insure that the proper
modes have been selected in the previous screen. If this information is correct, try
reversing the valuein the shaded box from -100 to +100 and retest.
On JR 10 series systems, please also check to insure that the gear switch has
been inhibited through
code 17 function
select. If the gear
switch is active, the
G550T will not change
modes correctly as
described.
JR 8103 Systems
Step 1: Access Program Mix 3 from the function mode and set the values as shown
in the screen at right.
Make sure the switch position (SW) is set to F-S12. This indicates that the mix
will be activated when the flight mode switch is moved to positions 1 or 2 only.
Note: For proper operation, check to insure that all tail rotor mixing valueshave
been reset to 0 for theflight modes that tail lock mode willbe used.
Step 2: Turn the system ON, and while watching the LED indicator on the amplifier,
move the flight modeswitch. The LED
should change from red (rate) to green
(tail lock) as the flight mode switch is
moved. Set the rate or tail lock modes to
the desired flight modes. Our example
shows the selection of rate mode for
hover and throttle hold, and tail lock
mode for stunt modes 1 and 2.
GYRO GAIN SETTINGS
Adjust the gyro gain of your radio system as follows:
JR 10 Series systems
Step 1: Access the gyrogain function (code 44).
Step 2: Press “SEL“ until “Auto” appears on the screen.
Step 3: Set the gain values as shown:
(please note that for this example, gain value 2 will not be used).
Step 4: Press “PAGE” and select the gain values for each flight mode as shown.
JR 8103 Series
Systems
Step 1: Access the
gyro gain (Gyro Sens) function from the function mode.
Step 2: Press the + or - key until “AUTO” appears on the screen.
Step 3: Press “SEL”
twice and select the
following: NORM:0,
STUNT:1
Step 4: Set the gain
value as shown in the
screen at right.
All other radio systems (JR 622,642, 652, and non JR systems)
Step 1: Access the travel adjust function of
your system.
Step 2: Confirm the gear switch position
as compared to the travel adjust values on
the screen and set the travel values for the
Gear channel (5) as follows:
Position 1 (Hover Gain): +90, Position 2
(Stunt Gain): -20
Step 3: Turn the system ON and verify that the gain value increased and decreases
when thegain switch is moved.
Note: All gain values shown in this section areinitial starting values only. Gain val-
ues can sometimes vary greatly due to the particular model, gear ratios, etc. Final
gain valuescan only be established after test flying. Please refer to theflight trim-
ming section of these instructions for more information.
TAIL ROTOR MIXING (RATE MODE ONLY)
Tail Rotor Mixing
While in rate mode, the G550T requires a small amount of tail rotor mixing to
achieve maximum performance. tail rotor mixing should never be used with the
G550T in Tail Lock mode, as this mixing will cause the G550T to be unable to
achieve and locate the correct neutral position for the servo.
Note: Due to the many variables involved with each different helicopter (engine,
blades, gear ratios, rotor, etc), the values shown are initial starting values only. Final
mixing values can only be achieved by test flying the model.
JR 10 Series Systems
Normal (Hover) Mode
PCM10/10S/10SX, 10SXII
Normal (Hover) Up 10% Down 10%
PCM10X
Normal (Hover)
Stunt (Flight) Mode
PCM10/10S/10SX
Stunt (Flight) Up +P4 Down -P4
PCM10SXII/10X
-6 0 -10
- 100%

JR 8103 Systems
Please refer to the
screen at right for the
proper starting values.
JR XP652 and Other Systems:
Up Mix (RVU): +/- 10%
Down Mix (RVD): +/- 10%
Change the mixing values from + to - to
establish the correct mixing direction.
Note: It is only necessary to assign tail
rotor mixing values to the flight modes that
the G550T will be used in standard rate
mode.
FLIGHT TRIMMING
Tail Rotor Trim Adjustment
On the first test flight, it may be necessary to adjust the trim of the tail rotor
mechanicallyif the model pirouettes slowly in either direction.
As with all heading hold type gyros, make any tail trim adjustments in rate mode
by adjusting the tail rotor control rod mechanically.
Do not usesub trim or the transmittertrim to make these finetrim adjustments,
as this will cause an out of trim situation when the tail lock mode is in use.
Adjust the tail trim by lifting the model into a stationary hover, and note the direc-
tion the mode pirouettes. Land the model, and adjust the tail control rod length as
needed. Continue this procedure until the heliwill remain in a stationary hover, with
the tail remaining straight. Once this adjustment has been made, the G550T can be
returned to tail lock mode if desired.
Note: While in tail lock mode, the G550T will automatically establish the correct
neutral position of the tail rotorwithout the need to re-adjust the linkage.
GAIN ADJUSTMENT
Hover
Lift the heli into a stationary hover, while looking for any side to side movement
(hunting) of the tail rotor (yaw axis). If the model displays a Hunting tendency,
reduce the gain value by 5% and retest. Reduce thegain as needed until the model
will maintain in a stationary hover without hunting.
If the gain value is below 70% in hover, move the control ball in 1 hole on the tail
rotor servo arm and retest. If the gain value reaches100% and no hunting occurs,
move the control ball out 1 hole on the servo arm and retest.
The ideal gain setting when using a rotor rpm of between 1300 and 1400 rpm is
in the range of 90-95% gain. This will indicate that the control system has been set
to the optimum mechanical settings.
Forward Flight (Stunt)
From a hover of at least 15’ high, move the flight mode switch to the stunt posi-
tion, and begin to transition into a very slow forward flight. If hunting occurs, move
the flight mode switch back to the normal position and land the model. Reduce the
gain by 5% and re-test. Continue this procedure until all hunting is removed with the
model at full forward speed. The final gain value should be in the range of 55-80%.
If the gain value isbelow 50%, move the control ball in one hole on thetail servo
arm and retest. If the gain value is above80%, move the control ball out one hole on
the tail servo arm and retest. These values are based on a main rotor rpm in the
range of 1650 — 1750 rpm.
PIROUETTE RATE BALANCING
(Experienced pilots only)
Lift the model into a stationary hover. If you are comfortable, perform a full stick
pirouette to the left, and then to the right while noting the speed in which the model
rotates. If the model rotates more quickly in one direction that the other, adjust the
travel adjust value in your radio program down on the fast side and retest. When
completed, the model should pirouette at an equal rate in both directions.
Tail Rotor Blade Length
In most cases, choosing the correct tail rotor blade length can play a big part in
the overall performance of a gyro.
As a starting point, a 60-size heli with a 4.93 to 5.18 tail gear ratio performs very
well with a tail rotor blade length of approximatelt. 95 mm. We recommend NHP tail
rotor blades (NOH195) for their superior rigid and overall performance.
When stopping after a pirouette, if the model displays a “rebounding” motion in
one or both directions, this isgenerally caused by thetail blade length. Lengthen or
shorten the tail blades until this rebounding is removed. Since there are manyvari-
ables that can also cause rebounding (rigidity of the helicopter frame and tail boom,
etc), proper adjustment can only be achieved through test flying.
WARRANTY COVERAGE
Your new equipment is warranted to the original purchaser against manufacturer
defects in material and workmanship for 1 year from the date of purchase. During
this period, Horizon Service Center will repair or replace, at ourdiscretion, any com-
ponent that is found to be factory defective, at no cost to thepurchaser. This warran-
ty is limited to the originalpurchaser of the unit and is not transferable.
REPAIR SERVICE INSTRUCTIONS
1.Return your system components only. Do not return your system installed in a
modelhelicopter, plane, etc.
2.Use the original carton/packaging (molded foam container) or equivalent to ship
your unit. Do not usethe carton itself as a shipping carton; you should package
the equipment carton within a sturdy shipping container using additional packing
material to safeguard against damage during transit. Include complete name and
address information inside the carton, as well as clearly writing it on the outer
label/return address area. Ship your equipment fully insured and prepaid. Horizon
Service Center is not responsible for anydamages incurred during shipping.
3.Include detailed information explaining your operation of the equipment and prob-
lem(s) encountered. Provide an itemized list of equipment enclosed and identify
any particular area/function which may better assist our technicians in addressing
your concerns. Date your correspondence and include your name, mailing
address, and a phone numberwhere you can be reached during the business day.
Within your letter, advise us of the payment method you prefer to use. Horizon
Service Center accepts VISA or MasterCard. Please include your card number and
expiration date.
4.Warranty Repairs. To receive warranty service, you must include a legible photo-
copyof your original dated sales receipt to verify your proof-of-purchase date.
Providing that warranty conditions have been met, your equipment will be
repaired without charge.
5.Normal Non-Warranty Repairs. Should your repaircost exceed 50% of the retail
purchase cost, you will be provided with an estimate advising you of your options.
Mail your system to:
Horizon Service Center
4105 Fieldstone Road
Champaign, IL 61822
[phone]
www.horizonhobby.com
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