Manual Size: 1016.08 kb

Manual Size: 1016.08 kb
GNDConnectors for 2,4GHz Spektrum remote satellite receiver. One or two
receivers can be used. Always use receivers of same type (DSM2 or
The connector No.7 (term) has pulse input/output on all 3 pins. Use the
1-3 cable to connect a standard receiver. Never connect a power source
to connector No. 7!
Connection to receiver/satellites
Spektrum remote satellite receivers can be directly connected to the GT5. The
GT5 is working as the main unit to which you just have to connect the servos.
Also you can use GT5 with singlewire systems like Futaba S-Bus, Graupner
SUMD, BEASTX SRXL or PPM singlewire. In this case you just have to connect
the wire from the receiver to connection imp1 or imp2 (in case PPM
singlewire is used). Because these technologies constantly evolve we cannot
guarantee full compatibility. For this reason the operation is at your own risk.
Introduction / Safety notes
GT5 is a high performance 3-axis gyro system designed for flying flybarless
model helicopters. It is not a self-leveling training system for beginners and
cannot be used in combination with flybared helicopters. If you are not
experienced in flying model helicopters please contact your dealer or a local
club for further assistance.
GT5 has not been tested in combination with turbine powered helicopters.
For this reason we can give no clearance for using the GT5 in such models.
If you want to use it with turbines anyway, the usage will be on your own
dsm Satellite
Standard receiver
MEMS gyros with ± 1000°/sec for X-Y-Z axis
Tail servo pulse width
Tail control frequency
65Hz – 333Hz (571Hz with 760us)
Swash plate frequency
50Hz – 250Hz
Swash plate types
mCCPM and 90°, 120°, 135° (140°) eCCPM
29,5 x 32 x 16mm
15g without wiring
Operate Voltage
Foam Pads
This pin could be connected to battery
If you use the GT5 with an
electric helicopter and you
have a speed controller with
integrated BEC it's not
obligatory that you use an
external receiver battery.
1-3 RC-Cable
Transmitter setup
The swash plate mixing is done by the GT5. In the transmitter you must
choose as swash plate type „mechanical Mixing“ (mCCPM) or „1 servo for
each function“. You MUST NOT choose a swash plate type like 120° or 140°.
Make sure all servo throws (ATV) are set to -100 and +100 (standard
configuration for all transmitters) and all servo centers and trims are set to 0
(in all flight modes!). For initial setup the pitch curve also has to be set from
-100 to +100 (after the configuration of GT5 you can set different pitch
curves in your transmitter).
When using GT5 in combination with a standard receiver you need, besides
the 4 channels for the control functions and the channel for the throttle, a
sixth channel that controls the tail gyro gain. For this you may use your
transmitter's gyro menu or simply a dial or knob.
When using GT5 in combination with Spektrum remote satellites or a
singlewire receiver it is possible to adjust tail gyro gain and also swash gyro
gain. These can be controlled by two separate channels, one common channel
or you also may do without gain adjustment at all. Whatever you decide to,
make sure the transmitter is prepared for it.
As throttle signal is only passed through the unit in singlewire application
respectively is directly connected to the receiver, throttle is the only
parameter, that has not be treated specially. So adjust your throttle curves
however you like. Please note that for performing function assignment when
using a singlewire receiver it may be necessary to deactivate the throttle
channel, e.g. by using the autorotation switch.
The supplied foam pads are very hard but normally suited for all kinds of
helicopters. For some nitro powered helicopters or in general helicopters
with a high vibration level the use of softer pads is recommended. But be
aware that soft pads may cause the unit to sway and thus cause
malfunction of the GT-5 unit.
8 Imp2 Standard receiver / Channel 5 output
7 Term Standard receiver / PC
6 Imp1 Standard receiver / Singlewire input
5 Ail-r Aileron servo (right)
4 Ele Elevator servo
3 Ail-l Aileron servo left / Pitch servo (mCCPM)
2 Tail Tail servo
1 Throt Throttle servo / ESC
upwards or downwards on the touchpad.
Programming menu is divided into two main sections: “control” and
“setup” section. These two sections are indicated by the black and white
bar on the very left side. When entering programming menu you will be
located in control section at PID control menu which will be used very
often in later usage. For initial setup the more interesting part is setup
section which will be traversed from bottom to upper end. So move to the
menu above which is symbolized by a wrench and enter this by tapping
the touchpad twice.
Please pay special attention to the capability of your power supply as with
flybarless helicopters the peak power consumption of the servos can be
very high. With some BECs the voltage during hard flight may drop
dramatically and cause total system failure resulting in crashing the
helicopter. If the BEC allows to, using a buffering battery with equal voltage
level is mandatory. Consult the manual of the ESC and ask the
manufacturer for further assistance and capability of the BEC. If in doubt
using a separate power supply is recommended.
Entering programming menu
If you move the cursor upwards to the ACE-RC Logo
and hold it there for 3 seconds, you will enter the
programming menu of GT5. To select a menu entry
or confirm a value tap the touchpad with your finger
To move up/down in the menu or to
increase/decrease values slide with the finger
Connecting battery / BEC
GT5.2 package contents
32-Bit High Speed Processor
(for Nitro)
After powering up you will at first see the receiver
scan. If GT5 does not detect any receiver or shows
“not equal”, this is not of importance for the moment.
It may be necessary to program the correct receiver
type first.
Then you will see gyro initialization, during this time
“Do not” move the unit as GT5 tries to calibrate zero
positions of the gyro sensors (it is not important that
the heli is standing level to the ground, only it mustn't
be moved).
Finally you will see the main screen of GT5 as already
shown above. To interact with the unit touch with your
finger to the touchpad on left side of the housing. A
small cursor will appear on the left side of the display
in the area of your finger.
Touch Pad
Starting GT5
To avoid causing damage to the servos, do not connect the servos
until after the servo set-up procedure has been carried out step 5
& 6. To begin with, simply connect the GT5 directly to a 4.8Volt Rx
battery, or regulated 6Volt power supply, into the Ch1 (Throt) port.
On electric machines, make sure the ESC/BEC is set-up correctly
before connection to the GT5.
Very precise electric 3axis stabilization system
OLED Display with Icon based User Interface
Wear resistant „Touch-Pad“ for easy handling without the need for
additional hardware
Supports standard PPM receivers, Spektrum DSM2/DSMX & JR remote
satellite receivers and singlewire connection of Futaba S-Bus, Graupner
SUMD, BEASTX SRXL and PPM singlewire connection
Suitable for Futaba and JR Servo- & RC-plug systems
Compact size and lightweight
High-quality Aluminum Case for optimal heat dissipation
96 x 64 pixels OLED
General settings
The menu symbolized by the wrench is “General settings” menu. This
menu is divided into “Device settings”, “Servo settings” and “Sensor
settings”. When entering “General settings” menu again double tab the
touchpad to directly proceed with “Device settings”, which is the first menu
entry in the list.
The first item at device settings menu is “Orientation of the
unit”. As mentioned above you can install the unit flat or
vertical. Now you have to select how the unit is mounted.
Again double tab the touchpad to select the item
“Orientation”. In the center of the screen a pictogram will be
shown indicating the momentary selected orientation of the
unit. By sliding the finger up or down you can switch between
both options, the pictogram will show a horizontal or vertical
standing unit. When you have chosen the correct type, again
double tab the touchpad and the selection will be saved and
you will get back to the menu item selection.
For now the other available items are of no interest, so we
will skip them and directly scroll down until we reach the
“Exit” item. Select this item by double tabbing and you will
jump back one menu level to selection of “General settings”
Here again we are not interested in adjusting other items, so
again scroll down to “Exit” and leave “General settings”
menu by double tapping the “Exit” item.
Next menu item we have to adjust is in the “Receiver” menu. So now scroll up
to the next item which shows the outline of a receiver an enter it by double
tapping the touchpad.
d) Failsafe
After the setup of receiver type and control functions is
complete, choose “Failsafe” in “Receiver” menu and
increase the number to 5.
Failsafe is later used when no signal from the receiver
is received. For security reason it is important that this
item is properly set, especially to prevent the electric
motor from starting unwanted or to prevent blocking of
the throttle servo. When using Spektrum remote
satellite receivers that are directly connected to the
GT5, failsafe additionally will determine the positions
that are taken in the event of the radio link failure (this
implies that time is set larger than 0. If time is set to 0,
the last valid stick positions will be held in case of
signal loss).
Move the sticks on the transmitter to the desired
failsafe positions (especially throttle to 0) and double
tap the touchpad. You will read „No exit“. Scroll up so
you read „Yes“ and confirm the positions by double
tapping the touchpad. Now failsafe is set properly and
you can „Exit“ the „Receiver“ menu and proceed to the
next step in „Setup“ section which „Swash plate“
a) Receiver type
Directly select the first menu item which is receiver type
selection. It will automatically scan for connected
receivers and preselect the detected receiver type. It
should only be necessary to confirm the type by double
tapping the touchpad.
Receiver types in detail are:
(1) Standard receiver – this is any receiver which 5
channels are connected by multiple wires to imp1, term
and imp2 connectors.
(2)and(3) Spektrum DSM remote satellite receivers
connected to the white plugs in the side of GT5. Be very
careful on correct selection of the type used. If DSMX
satellites are used, select DSMX satellite. If DSM2
satellites are used, select DSM2 satellite. It does not
depend on the mode in which the satellites are bound!
So if you run a DSMX satellite in DSM2 mode,
nevertheless select DSMX satellite. Also you must not
mix different types of satellites. If you do not follow
these instructions, a link failure during subsequent
operation is very likely!
(4) Futaba SBus digital one-wire connection at port imp1
(by now only SBus1 is supported).
(5) Graupner HOTT SUMD digital one-wire connection at
port imp1. When using SUM0 mode select SPPM signal
(7) and connect to imp2.
(6) SRXL digital one-wire connection at port imp1 for
BEASTX or Multiplex receivers with SRXL data output.
(7) SPPM – one wire connection sending in a chain of PPM
servo signals. This protocol is used by Graupner HOTT
SUM0 mode or JETI receivers. Note that these receivers
must be connected to imp2 input!
Initial Set-up
For the moment it is recommended to disconnect all servos. Only receiver
and power source should be connected. When using the BEC of your electric
speed controller to power the unit, it is recommended to disconnect the
motor from the controller to prevent the motor from starting by accident.
GT5 can either be
mounted flat on the
top or bottom of the
heli (eg. on the gyro
platform) or vertical
(preferably on the side
of the frame of the
It is only necessary that the pin connector and the cables must be aligned
with or against the flight direction. The plugs of the cables must not show
laterally out from the GT5. In addition, the edges of the housing of GT5 must
always be aligned parallel to the three axes of the helicopter.
Channel 5 output:
Example: Governor
signal cable on nitro helis
and/or remote glow igniter.
S- bus
We remind you, that GT5 is made for use in RC helicopters and for this
reason it´s not a toy. Flying a helicopter has to be realized always on special,
approved places with the usual security precautions in order not to harm
yourself or property of other persons.
Any liability due to the mentioned notes in the upper part is disclaimed by
the manufacturer, THUNDER TIGER EUROPE and the seller.
Spektrum/JR Satellite Receiver or
Futaba S-Bus
1) The three bold bars show sensor movement – Aileron, Elevator and
2) GT5 will scan receiver type when initial. It will show receiver type,
if it shows " -- " means there is no receiver or wrong receiver type.
3) Voltage display Upper value: Voltage actually
Lower value: Lowest voltage(break-in)during flight
4) The numbers show channel information for each function. When sticks in
the transmitter are centered, the channels should be 0
5) The two numbers show swash gyro gain and tail gyro gain in percent.
These values never can get below 50 and above 150.
To prevent damage of the servos it is recommended to not connect the servos
and servo linkages unless you did perform initial setup. When using the BEC
of an electronic speed controller to power the system make sure the motor
can not start by accident. To prevent the controller from getting configured
incorrectly due to wrong signal output it also is recommended to not connect
the speed controller and use a separate receiver battery instead unless you
did complete receiver setup and gain full control over GT5's throttle output!
GT5 can be used with a broad variety of different receiver systems: Besides
using it in combination with a conventional standard receiver system you can
use GT5 in combination with different single line receiver systems and also
directly connect Spektrum remote satellites to the unit. Please note that
neither Spektrum nor we can guarantee for full range transmission and full
functionality when using the system solely in combination with remote
satellite receivers! This kind of application is not intended by Spektrum RC.
Also because of the variety of electronic manufacturers and electronic
systems on the market we can give no guarantee for failures and
consequential damage, if a malfunction is not directly attributable to GT5.
Flybarless System
Receiver menu
b) Spektrum binding
When using Spektrum remote satellite receivers you
now will have to bind the receivers first. Scroll down
until you read the menu item “Bind” and select it. The
LEDs of the satellites will then start to flash quickly and
you can initiate the binding process of the transmitter.
After successful binding, the LEDs of the satellites must
remain illuminated when the transmitter is turned on. If
this is not the case, it is necessary to repeat the
c) Function assignment
In the receiver submenu you have two options to
choose from. You can start with the default function
assignment (“Def.”), then no further steps are required
to put the system into operation. When scrolling down
one item and selecting “CH Sel” you will have to assign
each transmitter channel individually to one function.
- Default assignment
Futaba SBus
Swash gain
Swash gain
Collective pitch Collective pitch
Tail gyro gain
Tail gyro gain
- Channel Selection
When choosing “Ch Sel” you can assign functions step
by step by simply moving the desired stick/adjusting
the channel on the transmitter. For correct assignment
you have to make sure that each stick/function is
controlling exactly one channel, otherwise the detection
can't work correctly. So for the throttle stick you have
to lock the throttle output by using autorotation switch
or similar, as at first you will have to assign collective
pitch function:
After selection of “Ch Sel” you see a line in the middle
of the display and you can read “Pitch” on the bottom.
Now move the throttle stick to full deflection and then
back to initial position. You should see a small line
moving away from center line showing the stick position
and then the line moving back. When reaching the
center line again, pitch function should get assigned and
aileron is next. So now move aileron stick to full
deflection and back again to assign aileron. Then follow
elevator and rudder. When you proceed to assignment
of throttle function you now may unlock your
autorotation switch to gain back control over throttle
channel. Now you can move throttle stick again to
assign the throttle channel. It is of no harm if now also
pitch channel does get moved as this was already
assigned before!
Lastly you have to assign the two gain channels, swash
gain (“G SW”) and tail gyro gain (“G TL”). Here you
have several options:
- you can assign both channels as before by using
individual channels of the transmitter, e.g. using
different switches or gyro menus to adjust these
- you can assign both functions to one channel so you
only have one gain for everything
- you can skip one or both gain function assignments. To
do so you simply have to double tap the touchpad of the
GT5. Then the specific gain function will be fixed to
100% and can't be adjusted by transmitter.
- If you skip the assignment of swash gain additionally
you will be prompted to adjust the “AUX” channel which
is an additional servo output you can connect at imp2
connector. If you also don't want to use/assign this
function anyway, again double tab the touchpad to skip
this assignment.
Swash plate setup
a) Update frequency
Select Update frequency (in Hz) for the swash plate
servos according to the specifications of the servo
manufacturer. If analog servos are used, never set the
frequency higher than 65Hz (some very old servos
even only work with 50Hz correctly!). With analog
servos a higher setting leads directly to the destruction
of the electronics. Modern digital servos in most cases
can easily be used with frequencies of about 120 Hz.
High-quality digital servo with brushless or brushed
motor can usually be used with much higher
frequencies. Note that setting a too high frequency can
cause strong heating of servo motor and/or servo
electronics and result in the destruction of the servos.
Furthermore, the information provided by the servo
manufacturer are usually maximum values. Depending
on the ambient conditions such as temperature,
vibration level or supply voltage, it may happen that in
practice the servos can be operated only with a much
lower frequency. When in doubt, always set a lower
Servo update frequency. Although a low Servo update
frequency reduces the performance of the control
system, because this will then work slower, the servos
are also less stressed. We expressly point out that
setting a frequency higher than 50Hz is at your own
GT5 can not provide all the frequencies within
the specified range. It will then automatically
jump to the next possible value up or down.
b) Servo sub trim
Next three steps in list will concern trimming of the
servos connected to ail-r, ele and ail-l. Adjust the
servos so that servo horns are perpendicular to the
linkages, swash plate is leveled and the rotor blades
have 0° of pitch.
c) Swash type/Servo adjustment
Choose the correct swash plate mixing type. When
your helicopter's swash plate is mixed mechanically
choose mCCPM (4). In this case the swash angle is not
of interest.
This option contains of two parts! After selecting the
appropriate swash type you will see four options for
adjustment of servo directions. Move the collective
pitch stick up and down and check, if the swash plate
also is moving up and down or if the servos are moving
in different directions. In this case scroll up to the next
option and try again. Repeat this until you have found
the correct servo directions. Then check cyclic input: If
inputs move servos into opposite direction, do not
reverse the servo directions anymore. Only reverse the
control input for aileron or elevator function by using
thereverse function of the transmitter for the
corresponding channel! In this way you can also
reverse the pitch function, if pitch stick is adjusting the
blade pitch in the wrong direction. If you're ready
confirm the directions by double tapping the touchpad
and proceed to the next step.
d) Virtual rotation
If the helicopter is equipped with a multi-blade rotor
head, which requires an electronic swash plate
phasing, you can set this here at the point Virtual
rotation. Make this setting only, when servo directions
and swash plate geometry have been set correctly
above and the swash plate itself responds correctly to
To find the correct value, align the rotor head so that
one rotor blade is parallel to the tail boom. Control only
the elevator function, the blade should not move.
if you move the aileron stick, the blade must initiate a
turn to the right. Adjust the Virtual rotation until this is
the case. To cross-check, you can also align a rotor
blade at a right angle to the tail boom. The blade then
should not move when you apply the aileron function,
but moving the elevator function should move the
blade so that the helicopter would rotate forwards or
e) Servo throw
The rotor head should create 0° of blade pitch angle
when activating this function. Pitch stick is locked.
Make sure that the transmitter's stick output actually is
set to 100% for the measurement process (check
f) Pitch range (A & B)
Here you can set the maximum collective pitch angle
for both directions. The adjustment should always
be performed with linear and unchanged pitch curve
in the transmitter (i.e. pitch curve from -100 to
+100). In addition, the pitch angle must be set only
after the Servo travel adjustment has been done
correctly. Otherwise, a subsequent change of the
Servo travel would affect the pitch angle.
After completing the whole setup, you can adjust
the pitch curves in the transmitter as you like, e.g.
by changing pitch curve in different flight phases.
The values set here will only set the maximum pitch
d) Servo limit A & B
Next two steps concern servo limit adjustment. Move
the rudder stick to the right or to the left and adjust the
maximum possible deflection of the rudder servo with
limit A or limit B. On most helicopters, the sensible
maximum deflection is determined by the tail pitch
slider. But note that there are helicopters, which
enable a very large angle of the tail rotor. Here the
limit should not be set as large as possible, but only as
large as necessary. Too extreme pitch angles may
otherwise cause the tail rotor blades to stall at certain
maneuvers causing a loss of performance and loss of
tail control.
e) Sensor direction
Turn the helicopter on the vertical axis. If the nose of
the helicopter is rotated to the right, the tail rotor has
to compensate so that the nose of the helicopter is
moved to the left, and vice versa.
You can check the correct direction very easy if you
only watch the tail rotor blades: During a movement of
the tail the rotor blades must be controlled so that the
trailing edge of the blades point in the direction in
which the tail is moved, the tail rotor then is producing
a thrust in the opposite direction and attempts to
counteract the movement of the tail.
Be very diligent with this setting. A wrong sensor
direction will cause the helicopter to rotate very fast,
when you attempt to lift off the heli as the tail gyro will
not compensate but amplify the deviation of the tail
h) Sensor directions
Last two points in swash plate menu are about
adjustment of sensor directions:
Elevator sensor - Tilt the helicopter on the elevator
axis and observe the compensatory movement of
the swash plate - it has to act against the movement
of the helicopter. So if the nose of the helicopter is
rotated towards the ground, the swashplate should
tilt backwards, just as you would enter a command
to pull elevator back. Same as when the heli is tilted
back, the swashplate must steer forwards.
Aileron sensor - Tilt the helicopter around the
longitudinal axis to one side and watch the
compensatory movement of the swash plate - it has
to act against the rolling movement. Thus, when the
helicopter is tilted to the right, the swash plate
needs to perform a control command to the left.
Similar when the heli is tilted to the left, the
swashplate must steer to the right.
Be very careful when doing these adjustments! A
wrong setting will inevitably lead to the helicopter
being destroyed at liftoff!
f) Pirouette correction
Finally you have to check for correct direction of
pirouette correction and adjust if necessary. When
entering this step the swash plate will be tilted
forwards or backwards automatically. Now the
helicopter must be rotated on the vertical axis, while
the swash plate has to be observed. If the
compensation direction is correct, the swash plate will
keep its position in space. When the swash plate
rotates with the movement of the helicopter, however,
the direction has to be reversed.
Pirouette correction is necessary so that the helicopter
does not rear up when the tail is rotated in fast forward
flight. As the swash plate is tilted forward in forward
flight, without compensation it suddenly would show to
the side when performing a pirouette. The system
could not recognize the rotation fast enough.
This was the last step of initial setup. You can now exit
the menu sections and go back to flight mode by
clicking the exit symbol on the top or bottom of menu
list. Alternatively you could simply wait until the Exit
timer has counted down.
After swash plate setup now we also have to adjust the parameters for tail rotor.
So for the last step in initial setup select the tail rotor pictogram in „setup“ section.
Tail rotor setup
a) Center pulse
First menu item in „tail rotor“ menu is the center pulse
for the tail rotor servo. Almost all servos use a center
pulse of 1500μs. Only some special tail servos from
Futaba, MKS and other use a shortened center pulse of
760μs. These servos are specially designed for use
with gyro systems. You can not plug them directly to a
remote receiver. A similar type also exists from
Logictec which uses 960μs center pulse.
When a special center pulse is required, this is usually
printed on the servo case or mentioned in the manual
of the servo. Otherwise it is assumed that a servo has
to be operated with 1500μs (some servos also are
specified with 1520μs - this is not a problem here: use
1500μs). If you set the wrong pulse width, most servos
won't react and appear as if they were not plugged in.
For safety reasons it is recommended not to plug in the
servo until the center pulse has been changed or at
least remove the servo horn to prevent from damage.
b) Update frequency
Select Update frequency (in Hz) for the rudder servo
according to the specifications of the servo
manufacturer. If an analog servo is used, never set the
frequency higher than 65Hz. With analog servos a
higher setting leads directly to the destruction of the
electronics. Modern digital servos in most cases can
Preflight check
When being back in flight mode check if all functions do
work as you would expect. Recheck the sensor directions
by tilting the helicopter back and forth, left and right and
rotating it on vertical axis and watch the reaction of
swash plate and tail rotor. They always have to
counteract against the rotation with a movement that
should compensate the rotation. Note that in flight mode
the reaction of the servos will be much less than in
adjustment menus!
Check the display: Voltage should stay stable when
moving all servos simultaneously and channel display on
the very left should show 0 at least for aileron, elevator,
rudder when these sticks are centered at the transmitter.
The two values for swash and tail gain at the bottom right
corner should be set to 100.
When the servos seem to get out of sync after doing
some stick movement this is no issue as in flight mode
the control system is working and does not know that the
heli is standing on the ground. If you move collective
stick to center and give a short aileron or elevator input
In “control” section you have access to adjusting the control system of GT5
and you can adjust the control behavior of stick inputs. Additionally we will
mention a few parameters in “General settings menu” of “setup” section, as
these are of minor importance and have been left out when making the initial
Control system menu is separated into adjustments for swash plate and tail
gyro. Please note that all adjustments in swash menu will be scaled by the
swash gain. All adjustment of the tail gyro system will be scaled by tail gyro
gain. So 100% gain means the values are used 1:1 as you can read them.
When setting the gain to 50% most of the values only will have half of the
effect as you did adjust.
b) Elevator/Aileron/Rudder rate
The functions Elevator rate / Aileron ratedetermine the
maximum achievable rate of rotation that can be adjusted
by a given stick deflection. This function acts as a linear
magnification/reduction of the control stick throw.
Alternatively (or additionally) you can adjust the stick
throw for the corresponding function in the transmitter,
e.g. by using Dual-rate function.
Please note that changing the rate of rotation/stick throw
will not have any visible effect on the deflection of the
servos when the GT5 is in flight mode. Also remember
that when making adjustments in GT5 regarding the
swash plate or tail servos the stick throw in the
transmitter must always be at 100% (the setting of the
rotation rate in GT5, however, will not have any effect).
By using Expo the response of the system to motion of the
stick in the center position can be alleviated. So small
control movements can be performed more sensitive. On
the other hand, if Expo is adjusted into the negative
range, the response to small stick movements is
It is not recommended to additionally use the Expo
function of the transmitter! The superposition of several
Expo curves can lead to very unexpected control
behavior. If you prefer to use the Expo function of the
transmitter, set Expo in GT5 to 0.
b) Tail gyro adjustment
PID Control system
(1) Stability
Stability primarily provides for holding the tail when
changes in rotor torque occur. If the value is too low,
the tail rotor responds very spongy to rudder inputs and
will continuously tend to rotate in one or the other
direction if pitch, aileron or elevator input are applied.
Too high Stability, however, will cause the system to
overcompensate. A fast tail oscillation will occur in fast
forward flight or even while hovering. The approach to
determine the optimal value is to gradually increase the
parameter until the tail just starts to make noise or just
starts to slightly overcompensate in very fast forwards
or backwards flight. In this case now decrease the
stability by 5 points and the tail rotor should hold fine
(2) Consistency
After adjusting Stability now do fast forward flying and
make pirouettes by giving uniform rudder stick input. If
the tail does not rotate uniformly but produce a
weather vane effect (slowly struggling against the
wind, but turning around fast when reaching the apex
of the wind), increase Consistency. Note that the higher
the value, the more synthetic the rudder control will
feel because the gyro system then more takes over
control. So only adjust this parameter just as high as
Even if very high values in the range of 100 do not give
the desired result, it is recommended to try different
tail rotor blades (different brand, different material,
greater size). Possibly the tail then can not provide the
necessary thrust to compensate the occurring loads.
Another possibility for poor tail performance could also
be that the allowed pitch angle of the tail rotor blades is
too large, so that the tail rotor will stall at large control
inputs. In this case test if reducing the tail servo limit
may change the tail behavior.
(3) Smooth stop
Increase this parameter to cause the tail rotor stop
softer and thereby more precisely after applying rudder
input. Especially when the tail rotor tends to stop short
but then overshoot slightly, this parameter should be
increased. A typical value that fits for most helicopters
is in the range around 5.
(4) Stop asymetry
When the tail rotor does stop softer/harder in one
direction than in the other you can use Stop asymetry
to move the effect of Smooth stop into one direction.
(5) Torque compensation
To support the tail gyro system when fast changes in
rotor torque occur some amount of cyclic or collective
stick input can be mixed directly to the tail servo
output. So the tail servo will already start to move in
the moment when the torque is about to change, not
just after.
If for example a large pitch input causes the tail to
shortly turn away with the direction of rotor torque then
adding some amount of Torque compensation in the
counter direction can be useful. On 700 size helis like
Raptor e720 a value of 40 for pitch should be a good
starting point. Cyclic compensation usually is not
Note that this parameter can be adjusted to both
directions. The sign has to be chosen so that the tail
rotor is controlled against the main rotor’s torque
direction when cyclic or collective pitch stick input is
applied. At 0° pitch there is no mixing to the tail rotor
servo and the mixing will increase (always to the same
direction!) the further the sticks are moved away from
the center position. For helicopters with main rotor
rotating in clockwise direction the tail rotor should
always cause a movement of the helicopter to the right!
a) Swash plate adjustment
(1) Stability
Stability is used to directly correct a sudden deviation
from the flight path with a counter reaction. On the
swash plate, this value can be adjusted over a very
wide range, changes will only have very little effect.
When this value is set too high, typically a very fast
oscillation of the rotor pane will occur. If Stability is too
low, the helicopter will not track exactly, e.g. when
giving fast collective pitch input the helicopter will not
rise straight but will tend to one side on aileron or
elevator axis. Also in fast forward flight, when the
helicopter does not track exactly and reacts nervous
and tends to break out to one side, you should increase
The default value of 80 should be sufficient for most
applications. On 450 size helis (Mini Titan 325/360) or
smaller, the value should be reduced due to the low
inertia. Start with a value of 60 here.
(2) Consistency
This is the first setting that you should consider more in
detail and that may need to be optimized by the pilot!
Consistency serves for controlling the rotation rates
and for keeping the helicopter on spot. If possible you
should fly one or more stationary elevator flips and then
stop in horizontal position. If the heli does not stop
immediately but continues to rotate a few degrees,
Consistency is too low. Increase this value just until the
helicopter stops on the spot. Do not increase it
anymore, as if it’s set too high the helicopter will swing
back slowly when stopping from a rotation. In addition
the stick feeling will get unnatural and indirect, as the
higher the value, the more the control system takes
over control.
A further effect of Consistency is that the helicopter
better remains in one position, the higher the value is.
So the setting also affects the consistency of 0 rotation
rate. If the helicopter in hover flight does move around
very much when you release the sticks, then this also is
a sign that the value is set too low.
For most helicopters values between 80 and 90 are
(3) Response
This parameter is of minor importance!
Increasing Response will make the control system to
react more aggressive. If the heli has the tendency to
oscillate lightly when a stick input is applied, you can
increase this value. It then may lock in more accurate
and harder. But if the values are too high, this can
cause the rotor blades reaching their aerodynamic limit.
Often you literally can hear the blades stalling when
quick changing cyclic stick inputs are applied. The
control then will feel greatly delayed when making fast
directional changes (e.g. when doing fast TicTocs).
On the other hand, reducing the value against 0, will
make the system react softer and smoother and as a
result of this also stick inputs will feel softer and
The default value of 15 should not be changed under
normal circumstances.
(4) Stick mix
This is the second important parameter which has
fundamental influence on the behavior of the
Stick mix determines how much part of the stick signals
is directly passed to the servos. The higher the value,
the more natural and direct the helicopter feels to cyclic
control inputs. However, as Stick mix is not evaluated
by the control system, increasing the value too much
will cause the helicopter to wobble after stick inputs, as
stick control will cause more servo movement than
necessary which the control system then has to correct
additionaly. So Stick mix should be set just as high as
the heli will not wobble when giving cyclic control
The setting of this parameter strongly depends on the
rotor blades used. With special flybarless blades values
between 70 and 80 should be possible. But also values
from 30 to 40 may be normal under certain
circumstances. If you only can reach very low values
and the helicopter therefore feels very indirect, then it
In this case you are allowed to temporarily use the stick
trim of your transmitter to compensate the drifting. As
this trimming will only last until the next power up, now
land the helicopter and enter “Stick” menu in “control”
section. Double tab the menu item “Trim save”. You will
be asked to confirm the save. Click “YES” and the current
trimming of your transmitter will cause a re-trim of the
servo mid points. Now you can move the trims in the
transmitter back to zero. The trimming will stay saved in
If you want to clear the trimming, select menu item “Trim
clear” and confirm the deletion.
is advisable to test a different brand of rotor blades.
(5) Speed stability
Fly fast forwards at high altitude and then suddenly
apply negative pitch. Ideally the helicopter should
maintain its alignment as it looses altitude. If the
helicopter's nose moves down sharply (undercuts),
increase Speed stability. Alternatively, you can also fly
a big looping: when the heli tends to rear up even if you
do not apply back elevator all the time, the value also is
too low.
Values from 20 to 30 are considered to be in normal
range. Set the value just as high so that the heli does
not show the behavior as mentioned above. Values
above 50 should be avoided as this can result in causing
control artifacts, leading to some very unexpected
movements (the system does compensate too long
then). Also high Speed stability values can cause a slow
wag on the elevator axis in straight forward flight.
Similar to Stick mix the type of rotor blades used has
great influence on the effect of this parameter. In
particular, the use of very maneuverable blades with
center of gravity very close to the blade root, which
have been designed for aggressive 3D flying with
flybared helicopters, can cause this parameter not
being useful at all. Only the use of fast and powerful
servos (or changing the rotor blades of course) can help
here then!
Additional parameters
GT5 can not provide all the frequencies within
the specified range. It will then automatically
jump to the next possible value up or down.
When a servo with 760μs center pulse is used,
an Update frequency of up to 571Hz can be set.
For other types, the maximum frequency is
c) Sub trim
Adjust the tail linkage according to the manufacturer of
the helicopter. The rod should form a right angle with
the servo horn when the servo is at center position and
the tail rotor angle should be set so that the tail rotor
will produce thrust slightly against torque. When sub
trim adjustment was entered, the servo will not
respond to stick movements or commands of the gyro
system and will stay at the trimmed center position.
Use sub trim to fine adjust center position.
g) Cyclic limit (maximum servo throw)
Push the throttle stick to full positive and negative
and simultaneously move aileron and elevator stick
in all four directions (be careful, servos may jam!).
Reduce or enlarge the Cyclic limit so that the servos
just do not jam in any of the possible maximum
positions. This prevents the servos from blocking in
flight and on the other hand, the maximum possible
control for the system is guaranteed. If there is
some more leeway in one place than elsewhere this
is not a problem. The cyclic boundary affects all
positions and the adjustment should be based on
the place where the servos could jam the earliest.
Do not reduce the cyclic boundary unnecessary.
Always try to achieve the maximum possible throw.
The Cyclic limit has no effect on the rate of rotation
in flight. If you want to make a change here, e.g. so
that the helicopter does not react so strongly to stick
movements, use the settings at “Stick” menu in
“control” section.
to full deflection all swash servos will get back to center
positions. Also take care that the tail servo is centered
when taking off as the gyro may have moved the servo
to full deflection due to moving rudder stick on the
ground or carrying around the helicopter.
Now you should be ready for take off. If you are a
beginner pilot or if you never have flown a flybarless
helicopter before please read on and note the hints
regarding adjusting expo and rotation rate, as the
flybarless helicopter may react very sensible to your
control input, in a way you did not expect.
In general please note the hints about adjusting swash
and tail gains and the control loop as it may be necessary
to fine tune the behavior of the system slightly.
easily be used with frequencies of about 120 Hz.
High-quality digital servo with brushless or brushed
motor can usually be used with much higher
frequencies. Note that setting a too high frequency can
cause strong heating of servo motor and/or servo
electronics and result in the destruction of the servo.
Furthermore, the information provided by the servo
manufacturer are usually maximum values. Depending
on the ambient conditions such as temperature,
vibration level or supply voltage, it may happen that in
practice the servos can be operated only with a much
lower frequency. When in doubt, always set a lower
Servo update frequency. Although a low Servo update
frequency reduces the performance of the control
system, because this will then work slower, the servo
will also be less stressed. We expressly point out that
setting a frequency higher than 65Hz is at your own risk.
Dual-rate and servo throw in transmitter; also the
stick output is indicated in the display of GT5 when
it is in flight mode).
Measure the cyclic pitch range, either on aileron or
elevator: you should see 8° of cyclic pitch angle
when giving 100% stick input. Adjust the value until
the required angle on the rotor blade is applied.
To measure the deflection of the aileron function,
align the rotor blades in a line to the tail boom. To
measure on the elevator function, align the
blades/rotor head at right angles to the tail boom.
Keep in mind that most helicopters are slightly tilted
forward, so the rotor blades are not necessarily
aligned to the ground at 0° pitch!).
It is sufficient to measure the blade angle on one
axis, aileron or elevator. Usually there might be
slight variations in pitch angle between the two
functions, or even within a function, e.g. a few 10ths
of a degree more aileron pitch to the left than to the
right. This is often caused by the nonlinear rotor
control and servo movement and should be no cause
for alarm! It is sufficient that at least the applied
cyclic pitch has an angle of 8° on average.
c) Stick tolerance
Stick tolerance determines the range in which GT5 reacts
to changes in stick position. A high Stick tolerance creates
a greater stick deadband. This can be useful when the
control stick of the transmitter does not work accurately
and will not properly center to zero position. You can see
this effect when the helicopter in flight sometimes drifts
slowly to one side. In particularly severe cases it can be
seen on the channel display of GT5 as some channels
jitter, jumping back and forth between two values.
Additional parameters of “General settings” menu
a) Device menu
(1) Exit time is a countdown timer for the menu. When
the countdown finishes, GT5 automatically jumps back
into flight mode. This prevents that the helicopter is
started while the menu is still active.
(2) By using Reset all parameters in GT5 are reset to
default. Only the settings of the receiver system, the
function assignment and the fail safe positions won't
be reset for security reasons. To initiate reset double
tap the “Reset” option. Then you will be prompted if
you're really sure. Select „YES“ and again confirm by
double tapping. After a reset do not fly!
b) Servo settings
The parameter Servo delay level (dynamic) is a filter
that will be mixed into the servo control. This filter causes
the servos not to make large movements in one step.
Especially in helicopters with high vibration level this can
prevent from an excessive load on the servos through the
ever changing movements. The servos remain much
cooler and their power consumption is reduced. At level 0,
however, all the control commands from the control is
passed directly to the servos.
We recommend not to change the default setting of Servo
delay level and primarily reduce the Update frequency, if
the servos get remarkably warm. If you are sure that the
servos can be operated with a certain frequency (e.g. in
electric helicopters), then possibly by increasing the Servo
delay level heating and the power consumption may be
reduced. A reduction of the Servo delay level or disabling
this parameter is not recommended in general.
You can adjust the levels for swash and tail servo
c) Gyro settings
In sensor settings menu you will see several options. The
first three options are used for calibration of sensor axis.
Do not change these values, they are set by the factory!
It is recommended to note these values in the manual for
later reference if you change these values by accident.
It is factory set and not of further interest. It can't
be changed anyway.
Other item of interest
Stick input
a) Trim save/Trim clear
Under normal circumstances it is not allowed to use sub
trim function of your transmitter. Sub trim would cause
a constant rotation command to the control system.
Anyhow it may happen, that the heli drifts slightly while
hovering due to bad balancing of the center of gravity
or due to bad servo trimming or bad linkage
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