ALZRC 3GYS User manual

Instructions for the ALZRC 3-axis gyro
1. Introduction
ALZRC 3GYS is a small, light weight, high-performance 3-axis gyro, for vario s levels of electric and gas
helicopters. It ses a High-performance processor, which can do very fast operations. Its main se is for the
control of RC model helicopters, and can be sed as a stand alone tail rotor control gyro.
2. Specification
Size: 38.2mm * 26.2mm * 13mm
Weight: 26g (f ll metal shell, incl ding cable and pl gs)
Operating Voltage: DC 3.5V-9V
Operating C rrent: 60mA
Operating temperat re: -10° to +50°
Maxim m ang lar rate: 800 degrees / sec
S pport for the r dder servo: 1.52ms analog servo, 1.52ms digital servo, 760 s digital servo, 960 s digital
servo
S pport for swashplate servos: 1.52ms analog servos, 1.52ms digital servos
S pported remote control devices: PPM, PCM, 2.4G
3. Functions and interfaces
Connections to the receiver
Servo connections: r dder connected CH4, depending on the swashplate type, the swashplate servos are
connected to CH1, CH2 & CH3.
For example, for CCPM 120° (Heli 120), se the following connections:
CH1: Aileron
CH2: Pitch
CH3: Elevator
See the swashplate types diagram below for all connections. Note the CH1, CH2 & CH3 shown at the control
points of the swashplate.

S pported swashplate types
. LED indications
Red light Working in tail lock gyro mode
Bl e light Working in the non tail lock gyro mode
Red and bl e light Gyro has not received any signal
Red and bl e lights flashing
Initialization failed, please keep the gyro still
and the r dder stick at center
Red light keeps flashing Gyro in firmware pgrade mode
5. Gyro installation
◆ the gyro sho ld be installed in a vertical or horizontal alignment on a stable platform, as far as possible away
from the engine and other electronic devices.
◆ the gyro sho ld be installed sing do ble-sided foam adhesive between the gyro bottom and gyro mo nt. To
prevent transferring f selage vibration to the gyro, make s re the cables are not p lled too tight and that the
case does not to ch any other helicopter component.
◆ when installed in small electric helicopters, se a 2mm or 3mm foam do ble-sided adhesive pad.
◆ when installed in a large helicopter or when there is helicopter vibration, it is recommended to se a metal
plate between two foam do ble-sided adhesive pads.

◆The gyro has three installation directions that can be chosen: 1, 2 & 3
Direction 1:
Direction 2:
Direction 3:
6. Servo arm and connecting rod installation
6.1 Swashplate servo
◆ Firstly, confirm that the rotor head and swashplate mechanical parts are installed correctly, and move
smoothly, before being connected to the servos.
◆ The proposed position of the ball on the swashplate servo arm is: 250/450 helicopters to 12.5mm-13mm,
500 helicopters to 14mm-14.5mm, 600 level and above to 14.5mm-15mm helicopter
6.2 Rudder servo
◆ Firstly, verify that tail rotor mechanical parts are installed correctly, and move smoothly, by moving the tail
control p shrod by hand.
◆ The proposed position of the ball on the tail servo arm is: 250 helicopter to 4.5mm, 450/500 helicopters to
7.5mm-10mm, 600 and above helicopters to 13.5mm-15mm.
◆ Temporarily install the tail control rod on the r dder servo arm ball. With the servo arm sq are to the control
rod, adj st the length of the tail control rod for a tail pitch of 8 degrees.

Note: After completion of the above r dder set p, do not connect the r dder servo to the gyro.
7. Remote Device Settings
In the transmitter, create a new helicopter model witho t any mixing f nctions. Select 1 servo (90 degree)
mode (F taba: H1; JR: 1 servo NORM; Hitec A rora 9: 1 servo (90°)). For all channels, set the fine-t ning
val e (Trim) and the internal fine-t ning val e (S b-trim), to zero. Ens re that all swashplate and tail rotor
mixing f nctions are t rned off. Initially adj st the pitch c rve to be a straight line, from minim m to maxim m
pitch.
8. Programmer menu structure
9. Parameter settings
9.1 Connection and boot up
Note: Beca se the servo type has not been selected yet, don’t connect any servos at this stage, otherwise
they may be damaged.
T rn on the transmitter and receiver.
After power p is complete, connect the programmer to the gyro data port sing the data cable.

Note the correct orientation of the data cable pl g
The programmer will boot and display "ALZRC 3GYS Loading data!". After a s ccessf l connection the display
will show "Load s cceed!", and then displays the first men "Basic set p".
9.2 Monitor
Use the "Monitor" men to check the transmitter settings are correct.
When the screen shows "Basic set p", press the ENTER key to display "Monitor", and then press ENTER to
select it.
The first page shows the 4 signal channels from the receiver
A: Aileron channel, E: Elevator channel, R: R dder channel, C: Collective channel
To check that the transmitter has all the mixing f nctions t rned off, move each stick separately and check that
only the corresponding channel changes and the remaining channels remain nchanged.
Adj st all the transmitter channel directions, so for example, the r dder stick "R", shows "L" when the stick is
moved to the left and "R" when moved to the right. Note that “U” ( p) is stick p and not p elevator.
Position the throttle at mid stick and adj st all fo r channels on the monitor display so the val e shows 0. This
is done by sing the transmitters internal fine-t ning (commonly known as S b-trim). Look for the direction
letter changing for absol te center.
When each of the sticks are moved to the limit ( p, down, left and right), ens re that the val e displayed
shows 100. If not, adj st the corresponding channels end point adj stment (EPA) ntil it does read a val e of
100. Control sensitivity can be changed later with d al rates and expo.
Examples of stick travel where the val e sho ld read 100. Also note the "L", "R", "U" & "D".
Press the DOWN/DATA- key to select the second page, showing the transmitter channel gain signal and the
gyro parameter set c rrently in se:
"G" indicates the transmitter gain channel val e is displayed; "A" indicates tail lock gyro mode (heading hold);
"N" indicated non locked gyro mode (rate); "Condition:" c rrent gyro parameter set. For each gyro there are
two sets of parameters to choose from. Here the val e is j st shown, and cannot be changed.

A gyro mode switch sho ld be set p in the transmitter to change between locked tail and non lock tail mode.
The following table is a list of major transmitter brands showing the s ggested val es that sho ld be ses.
After transmitter set p, set the switch to the tail locked mode position. After the "G:" an "A" sho ld be
displayed. Toggle the switch to the non-locked mode position, it sho ld show "N", if set p correctly. It is
recommended to initially set the transmitter so that the display shows a gain val e close to 36. This can be
adj sted later after the tail behavior has been monitored d ring flight.
When finished, press the BACK key to ret rn to "Monitor".
9.2 Gyro installation position selection
When the screen shows "Monitor", press the DOWN/DATA- key to display "Installation Direction", and then
press ENTER to select it.
Select one of the three orientation modes for the gyro (shown earlier in the man al), to match the act al
installation in the helicopter. When finished, press the BACK key to ret rn to "Installation Direction".
9.3 Download model data stored in the programmer to the gyro
When the screen shows "Installation Direction", press the DOWN/DATA- key to display "Load model". Press
ENTER, then press UP/DATA+ or DOWN/DATA- keys to select one of the ten models, in which 1-5 are a
factory pre-existing set of model parameters, and 6-10 are reserved for 5 sets of ser's own parameters (see
instr ctions on sing the programmer's Model save and Model rename, in the Advanced men ). It is
recommended to starting with model parameters 1-5. Select the desired feel yo req ire, for example
"Beginner", “F-3C”, “Soft 3D” etc.
When yo have selected the model data to download, press ENTER. The following men will appear on the
display.
When the "Yes" is flashing, press the UP/DATA+ key next to the “Yes”. The selected model data will be read
from the programmer and sent o t to the gyro. When the download is complete, press the BACK key twice to

ret rn to "Load model".
9. Rudder servo type selection
When the screen shows "Load model", press the DOWN/DATA- key to display "Tail servo type", and then
press enter to select it.
There are five types of servos to choose from:
◆ "1520 s 72Hz" all the servos are analog servos
◆ "1520 s 250Hz" broadband digital r dder servo is a servo (F taba S9253, S9254, S9257, etc. and some of
the common digital servos). Main rotor servos are analog servos
◆ "1520 s 333Hz" broadband digital r dder servo is a servo (F taba S9253, S9254, S9257, etc.). Main rotor
servos are broadband digital servos
◆ "760 s 400Hz" r dder servo is a narrowband digital servos (F taba S9251, S9256, BLS251, MKS DS8910,
BLS980). Main rotor servos are broadband digital servos
◆ "960 s 333Hz" r dder servo is a digital servo (LogicTech6100G, 3100G, Hitec5083MG). Main rotor servos
are broadband servos
Use the UP/DATA+ or DOWN/DATA- keys to select the req ired servo type. When finished, press the BACK
key to ret rn to "Tail servo type".
9.5 Model type selection (helicopter swashplate type selection)
When the screen shows "Tail servo type", press DOWN/DATA- key to display "Model type", and then press
ENTER to select it.
There are five swashplate types to choose from: "Heli 120", "Heli 135", "Heli 140", "Heli 90" & "Heli Normal".
These are shown earlier in the man al. For example, for helicopters with 120 degree CCPM, select "Heli 120".
Use the UP/DATA+ or DOWN/DATA- keys to select the req ired swashplate type. When finished, press the
BACK key to ret rn to "Model type".
Yo can now connect the servos to the gyro, b t do not install the servo arms.
9.6 Servo tuning
When the screen shows "Model type" press DOWN/DATA- key to display "Servo trim", and then press ENTER
to select it.
Switch the gyro mode switch, set p earlier, several times q ickly, to re-initialize the gyro, and then leave the
switch is the non locked tail mode (rate). Set all transmitter sticks to the center position. Now fit the servo
arms.

Adj st the swashplate servos "Servo 1", "Servo 2", "Servo 3" val e, so that all the swashplate servo arms are
level and the rods are vertical. Then adj st the servo arm to the swashplate p shrods, so that the swashplate
is level. Now adj st the blade arm p shrods for zero degrees pitch.
Adj st the r dder servo "Servo 4" val e, so that the r dder servo arm and tail rotor control rod are at right
angles to each other.
Adj st the length of the tail rotor control arm for approximately 8 degrees of pitch.
When finished, press the BACK key to ret rn to "Servo trim".
9.7 Servo reversing
When the screen shows "Servo trim", press the DOWN/DATA- key to display "Servo reverse", and then press
ENTER to select it.
Move the throttle stick p and down and check that all of the servos move in the same direction and that the
ailerons and elevator also operate correctly. If not, adj st the "Servo 1", "Servo 2", "Servo 3" symbol. It may
sometimes be necessary to swap the aileron and pitch servo pl gs. Don’t worry abo t the collective direction,
at this stage.
Move the r dder stick and check that the tail moves in the correct direction (stick to the left, the tail pitch
changes to move the nose of the helicopter to the left; stick to the right, the tail pitch changed to move the
nose of the helicopter to the right). If not, change the "Servo 4" symbol to reverse the direction.
Note:
◆ See the “Main rotor collective pitch direction and range” men for reversing the collective.
◆ Be caref l when moving the r dder stick as the tail limits have not yet been set and the servo may try to
drive the tail past it’s limits.
When finished, press the BACK key to ret rn to "Servo reverse".

9.8 Servo position adjustment limit
When the screen shows "Servo reverse" press the DOWN/DATA- key to display "Servo limit", and then press
ENTER to select it.
Move the r dder stick to the f ll left and right position, and adj st the "Tail limit A" and "Tail limit B" so that the
maxim m travel is sed witho t any binding at the limit. Press ENTER to change the limit and BACK when
finished.
Move the Aileron stick f ll left and right, and adj st the “Aileron limit” to ens re the swashplate is at no point
jammed and stalling the servos.
Move the Elevator stick f ll p and down, and adj st the “Elevator limit” to ens re the swashplate is at no point
jammed and stalling the servos.
When finished, press the BACK key to ret rn to "Servo limit".
9.9 Main rotor collective pitch direction and range
When the screen shows "Servo limit", press the DOWN/DATA- key to display "Collective range", and then
press ENTER to select it.
Move the throttle stick to the top and check the collective moves in the correct direction. If not, change the
Collective range to a negative n mber of the same val e. Check the collective for the req ired pitch with the
se of a pitch ga ge, and adj st the range (-125 to 125) ntil this is achieved. This is s ally between 10 and
12 degrees. Check for eq al pitch in both directions. If they are not the same, then recheck the servo trim,
transmitter end points and that the Tx pitch c rve is straight, from minim m to maxim m pitch.
When finished, press the BACK key to ret rn to "Collective range".
9.10 Gyro direction
When the screen shows "Collective range", press the DOWN/DATA- key to display "Gyro direction", and then
press ENTER to select it.
Switch the tail to locked tail mode. Rotate the helicopter and check the movement of the tail pitch. The tail
pitch sho ld change in the opposite direction, as if to stop the rotation. If it does not, then change the "Yaw:"

symbol.
Pick p the helicopter and pitch the helicopter forwards and backwards. The swashplate sho ld try to remain
level (pitch forward, swashplate moves backwards; pitch backwards, swashplate moves forwards). If the
reverse happens, change the "Pitch:" symbol.
Pick p the helicopter and roll the helicopter to the left and right. The swashplate sho ld try to remain level (roll
left, swashplate moves to the right; roll right, swashplate moves to the left). If the reverse happens, change the
"Roll:" symbol.
When finished, press the BACK key to ret rn to "Gyro direction".
9.11 Total gyro gain adjustment
When the screen displays "Gyro direction", press the DOWN/DATA- key to display the "Gyro total gain", and
then press ENTER to select it.
"Yaw total gain:" tail rotor total gain, "Roll total gain:" aileron total gain, "Pitch total gain:" elevator total gain.
For the first flight, these val es sho ld be left as the defa lt. If the helicopter drifts in the hover, increase the
roll and pitch gain. If the helicopter oscillates in the hover red ce the roll and pitch gain. Us ally the yaw total
gain is left at the defa lt (100) and adj stments are made in the transmitter.
Note: The defa lt val es are 100 for yaw and 40 for roll and pitch.
After setting, press the BACK key to ret rn to "Gyro total gain".
9.12 Rotation direction setting optimization
When the screen shows "Gyro total gain" press the DOWN/DATA- key to display "Piro ette optimization", and
press ENTER to select it.
The swashplate will tilt at an angle. Note the direction of the swashplate. Rotate the tail of the helicopter,
making s re the programmer does not become disconnected. D ring the rotation the swashplate sho ld
contin e to point in the same direction, as the needle of a compass wo ld do it yo rotated the compass body.
If the swashplate does not maintain in the same direction, change the direction symbol and try again.

Rotate the tail. The swashplate sho ld still be tilted in the same direction.
When finished, press the BACK key to ret rn to "Piro ette optimization". The swashplate will ret rn to ne tral.
The 3-axis gyro adj stments are now complete. In the transmitter, yo can now set the throttle and pitch
c rves, d al rates and expo, to yo r preferred flight settings.
It’s now time for the test flight…
10. Flight Notes
◆ Always do reg lar inspections of the mechanical str ct re of the helicopter, checking for loose screws and
mechanical parts that are badly worn.
◆ Always check before each flight that the helicopter’s mechanical movement is smooth.
◆ If d ring the initialization, the body is not kept still or the r dder stick is moved, then gyro drift may occ r.
While keeping the body stationary and the r dder stick still, q ickly switch the gyro tail mode switch, a few
times, from locked to non locked mode. This will re-initialize the gyro and eliminating the drift. If after
initialization the red and bl e lights are flashing, move the r dder stick to the left, to restart the initialization.