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Connect the rudder servo to top connector.
Make sure the plugs go in the right way. Click on the
picture to the left to see what color wire should be on
what side. Run one of the extension cables that came with
the gyro from the middle connector marked 'To receiver 1-4'
to the rudder channel on the receiver (ch.4). Next run
the other extension cable from the bottom connector
marked 'To receiver aux' to ch.5 on the receiver.
NOTE: If you have the old style case, then the connector
on the gyro sensor box is used for factory programming
only. Do not connect anything to it. |
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Mount the Gyro on the back plate behind the
main shaft. Do NOT pay attention to the instructions for
gyro orientation. As long as you have the orange sticker
on top then you have it mounted in the right orientation.
I mounted mine with the arrows pointing left/right and
the cord coming out of the sensor box toward the back of
the helicopter (click on photo at the left). The gyro
comes with two pieces of foam tape that work really good.
I put one strip on the bottom left edge and the other on
the bottom right edge. If you need to replace the tape,
you can use the CSM tape part # CMLG150 |
| |
Before we continue it helps to understand the
characteristics of this gyro. You will notice that your
rudder stick only moves the servo for the first 75% to
the right and the first 25% to the left. The servo does
not move when the stick is past these positions. Also the
gain pot on the gyro sensor box does not work when you
use the remote gain. It does not matter what position the
pot is set to. The radio controlled gain takes priority.
Another thing to remember is that all heading hold gyros
have to initailize. This one takes about 9 seconds. Don't
move the helicopter during the first 9 seconds after you
turn it on. The gyro will let you know it's finished by
moving the servo just a little bit one way then back. It
will also turn on a red LED on the back of the gyro
sensor box. |
| Common misconception of all heading hold
gyros |
Another thing that a lot of people don't
understand is that the rudder travel adjust (ATV's /
EPA's) does not adjust how far the servo moves. You
cannot use this to prevent linkage binding. This
adjustment only effects how fast the tail moves (your
pirouette rate). |
| radio setup |
Disconnect the rudder link from the servo.
Turn on the radio and receiver. Wait 9 seconds for the
gyro to initialize. It will move the rudder servo a
little to let you know it's ready. Also you will notice a
red LED light up in the back of the gyro sensor box. |
| zero out anything that would effect the
rudder |
Press one of the 'Edit' buttons until the
screen gets to 'RVMX'. Now with the flight mode switch in
normal position, move the throttle stick all the way down
and use the Data '+' or '-' buttons to set the value to
zero. Flip to flight mode 1 (ST1) and set to zero and do
the same for (ST2). Now move the throttle stick all the
way up and set all flight modes to zero. Another thing to
make sure is turned off is the Stunt Trim. Go to 'STRM'
and set channel 4 and 5 to zero. |
| set pirouette speed |
Go to 'EPA' menu and adjust channel 4 to set
how fast the helicopter spins. Hold the rudder stick to
the left and set the value to 70%, hold the rudder stick
to the right and set it to 70%. This will set how fast
the helicopter rotates. You may want it faster or slower
so change the value appropiately. |
| set the gyro gain |
Go to 'GYRO' menu and set normal flight mode
to 0 and all others to 100%. Later you may need to adjust
this down a little to keep the gyro from 'hunting'. |
| set to normal mode |
While in Normal flight mode, move the rudder
stick to the right, then back to center, if the servo
does the same then you are in normal mode. If the servo
moves to one direction but does not move back to center
then you are in heading hold mode. If it is not in
standard rate when in normal flight mode, then go to the
'REV' menu and change the direction of channel 5. |
| servo direction |
Check the servo direction. Move the rudder
stick to the right and watch the servo arm. It should
move the servo clockwise which thereby should pull the
rudder control link forward. This will make the nose of
the helicopter rotate to the right (if you assembled the
hub the right way). If not, then go to the 'REV' menu and
change the direction of channel 4. |
| gyro direction |
Rotate the helicopter so the nose goes to the
left and watch the rudder servo. The servo needs to
rotate clockwise. If not, then flip the reverse switch
located on the back of the gyro sensor box. |

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With the rudder link disconnected from the
servo. The first thing to do is make the link slide as
free as possible. Adjust the guides to acheive the least
resistance. I added a slight bent to the front section of
the rod as you can see if you click on the photo to the
left. I did this so as to stop the resistance the rod had
on the first frame guide due to being pulled down to the
servo. I also used a JR Ball link resizing tool to remove
unecessary resistance from the ball links. Once you get
the link as free from resistance as you can, turn on the
radio and receiver. Wait 9 seconds for the gyro to
initialize. It will move the rudder servo a little to let
you know it's ready. Set the rudder servo arm so that it
points a few degrees clockwise of straight up (pointed
toward the front of the heli) with the rudder stick and
rudder trim centered. The best position for tail
centering is to adjust the rudder link so that you have 4.5mm
between the pitch slider and the tail rotor casing with
the collective stick centered up/down and left/right.
Check that the front link is centered with the servo arm.
If it's not, turn the link clockwise to move it toward
the back or counter clockwise to move it forward. Once
the center of the ball link matches with the center of
the arm and you have the 4.5mm at the tail slider, then
you can move to the next step. |
| |
Hold the tail rotor stick full right and pull
the control rod all the way forward. Note: The servo will
only move during the first 75% of stick movement. This
does not mean something is wrong, this is the way it was
designed. Hold the link over the servo arm to see which
hole it will align with and install the ball in that hole.
Mine worked out to use the hole that is 9mm from the
center. You want to use the one that is furthest from
center that does not allow the servo to mechanically bind.
After you mount the ball, confirm that it does not try to
pull the link further than it can mechanically go either
right or left. Now you can snap the link on the ball. |
| Flight adjustments |
The biggest thing that gets a lot of people
confused with heading hold gyros is how to center them.
To put it simply, you center Heading hold with the radio
and standard rate with the rudder linkage. First center
the rudder trim. Next flip into flight mode 1 (ST1)* to
get the gyro in heading hold. If the tail drifts to the
left or right then use rudder sub trim to correct that.
->*If you are learning to hover and not ready to fly
with a more advanced pitch/throttle in Stunt mode, then
set the pitch/throttle curve identical to that of normal
flight mode.
After you get the tail centered for heading hold then
switch back to normal flight mode. In a hover if the tail
drifts one way or the other then take the link off the
ball link from the rudder servo and turn it clockwise if
the nose of the helicopter drifts to the left and counter-clockwise
if the helicopter drifts to the right.Gain
settings:
For normal mode you want to increase the gain until you
see the nose of the helicopter wag (oscillate back and
forth), then back off the gain a few points. That will be
the highest you can set the gain. Do the same for HH.
NOTE: If you can't get a gain in normal mode that is
close to 100% then you may have too much vibration or the
servo arm is too long.
After all the previous settings are done you may want to
setup Revolution mixing for normal flight mode. Remember
to keep it set to zero for all flight modes that use
heading hold.
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