INSTALLATION INSTRUCTIONS FOR THE
HELI-MAX HM4000 HEADING LOCK GYRO
INTRODUCTION
Thank you for purchasing the Heli-Max HM4000 Heading Lock
Gyro. Please read through this instruction sheet before starting
installation. This gyro has been tested extensively and the
best initial settings are listed within this manual. The HM4000
Heading Lock Gyro is a high-performance, lightweight gyro to
be used with electric helicopters of any size.
Contents
(1) HMXM1012 Heli-Max HM4000 Heading Lock Gyro
❏
Required (Not Included)
(1) Electric Helicopter
❏
(1) FUTQ1000 Futaba Gyro Foam Mounting Pads
❏
30x30mm (3 pieces)
(1) Small, fl at-bladed screwdriver
❏
EPA / ATV (Tail Rotor): 70% (Left) / 70% (Right)
Dual Rate: 100% (Left) / 100% (Right)
Exponential: − 40% (Left) / − 40% (Right)
Trim Step (Tail Rotor Trim): set to 1 after initial fl ight
Gain: Normal 45% (AVCS), Idleup1 45% (AVCS), and Idleup2
45% (AVCS)
INSTALLATION
❏ 1. Once your helicopter is fully assembled and you are ready
to install the gyro, you should verify that the tail rotor slider and
linkage moves freely. Any friction will degrade the performance
of any gyro and shorten the life of the tail rotor servo. If there
is any friction in the tail rotor pitch control, please take a few
minutes now to fi x the problem.
❏ 2. Please follow the instructions provided with your helicopter
and install the tail rotor servo. Remove the servo arm attachment
screw and servo arm.
❏ 3. To remove any grease or mold release agents from the gyro
and helicopter, moisten a paper towel with isopropyl alcohol and
clean the bottom of the gyro and the gyro mounting location on
the helicopter. Before moving to the next step, allow time for the
isopropyl alcohol to evaporate.
❏ 4. Peel one side of the protective paper from the gyro mounting
pad. Carefully center the mounting pad on the bottom of the
gyro and press down fi rmly.
❏ 5. It is best to test fi t the gyro onto the helicopter. This will allow
you to fi nd the best orientation for the gyro, which will provide
the most convenient access to the wires and allow the best wire
routing. Please keep the gyro at least [76mm] away from the
main motor or electronic speed control. On most helicopters
available today, the gyro will mount either on the top or bottom
of the tail boom clamp. Please refer to the instruction manual
for your helicopter to determine the recommended mounting
location for the gyro.
❏ 6. Plug the gyro’s 3 wire connector into the tail rotor (rudder)
channel on the receiver (typically channel 4 for Futaba
transmitters). Ensure that the white wire is aligned with the
signal wires of the other plugs connected to the receiver.
❏ 7. Plug the remote gain wire coming from the gyro into the
remote gain channel on the receiver (typically channel 5 for
Futaba equipment). Ensure that the white wire is aligned with
the signal wire of the other plugs connected to the receiver.
❏ 8. Using the label as a reference, plug the tail rotor servo into
the side of the gyro. The signal wire must face the control leads
exiting the gyro and the black wire must face the outside of the
gyro. If necessary trim the connector as shown so it will fi t into
the gyro.
❏ 9. Once you have found the best orientation, you can peel
the protective paper from the mounting pad and mount the gyro
onto the helicopter.
❏ 10. Bundle the excess wires together using hook and loop
material or wire ties. Review your work and verify that none of
the wires can become entangled in the main rotor gear, swash
plate or other rotating components on the helicopter. Verify that
all of the wires are plugged into the correct locations and all of
the signal wires are in the correct location.
❏ 11. The setup discussed here will be for Futaba radio systems.
Most of the parameters should carry over to other brands of
transmitters. Please refer to your transmitter instructions for
exact programming instructions. Turn your transmitter on. Go
to the gyro function within the radio and enable this function.
Select the desired gain switch on the transmitter and set the
gain to +45% for gain A and −45% for gain B. These are
temporary settings that will be used for setup only. Verify that all
tail rotor compensation mixing (Revo Mixing) is disabled in the
transmitter and all offsets or sub-trims are set to 0.
WARNING
To prevent the possibility of the main rotors turning
during setup, you must disconnect the main drive motor
from the ESC or remove the pinion gear from the motor.
Failure to do this may result in injury to yourself or
damage to the model and its surroundings.
❏ 12. Connect the fl ight battery to the ESC on the helicopter.
You must allow 7 to 10 seconds for the gyro to initialize. During
this initialization do not move the helicopter. Once the gyro has
initialized you will notice that the LED status indicator on the
gyro will turn on.
❏ 13. Install a servo arm onto the tail rotor servo. Please note
the current position of the arm and move the tail rotor stick full
left. Hold for one second and allow the control stick to re-center.
If the servo returns to center every time, then you are in nonheading lock mode which is what we require to continue with
the setup. Please move onto the next step. If the servo does
not return to center, then you are in heading lock mode. Please
change the gyro gain switch on the transmitter and re-test until
the servo re-centers every time.
❏ 14. Now that we know the gyro is in normal mode we need
to position the servo arm properly. Remove the servo arm
and place it onto the servo so that the arm is perpendicular or
parallel to the servo. Most servos use an odd number of splines
so it is possible to achieve different mounting positions by simply
rotating the arm by 90º intervals. Once you have found the best
mounting position, remove the unused sides of the arm.
❏ 15. Mount a control ball onto the servo arm 7.5mm from
center. Apply thread locking compound to the screw and nut.
Reinstall the servo arm mounting screw.
❏ 16. Our goal is to have maximum mechanical throw without
any binding. The fi rst step is to verify centering and throw limits
for the gyro, servo, and helicopter. Move the tail rotor stick full left
on the transmitter and hold the tail rotor pushrod ball link over
the control ball on the tail rotor servo. Now perform the same
thing using full right tail rotor. Evaluate the alignment and throw
and make any length adjustments necessary to the t/r pushrod.
Once you have the throw centered, if you have determined that
the pushrod is not traveling far enough, simply move the control
ball one hole out from center on the servo arm. If you have
determined that less throw is needed simply move the control
ball in one hole towards center on the servo arm.
❏ 17. Apply full right tail rotor and verify that the tail rotor will
cause the nose of the helicopter to move to the right. If you
have trouble trying to determine which direction the tail rotor
operates for left and right, please refer to the helicopter’s
instruction manual.
❏ 18. Pick the helicopter up by the main shaft with the nose
facing away from you. Now rotate the nose of the helicopter to
the left (counter clockwise). While doing this verify that the gyro
compensates in the correct direction. In this example the gyro
would apply right tail rotor (clockwise) to compensate for the
helicopter rotating to the left (counter clockwise).
❏ 19. Set the gain to 45% heading lock mode. Set any secondary
gain %’s to 45% heading lock mode at this time. Later on you
can make adjustments as necessary.
❏ 21. Exponential should be used on the transmitter to help
soften the feel of the tail rotor stick. On a Futaba transmitter
use − 40% Expo to start with (typically this is channel 4 on
Futaba transmitters).
❏ 22. Please review your work and ensure all connectors
are fi rmly plugged in. Verify that the gyro compensates in the
correct direction and the tail rotor servo is responding in the
correct direction.
❏ 23. Disconnect the power from the helicopter for 30 seconds.
Re-connect the power, allowing 7–10 seconds for the gyro
to initialize. Once the gyro has initialized, the tail rotor servo
should center and remain there. If you notice any slow drifting
in the tail rotor servo, please try to trim this out using the tail
rotor trim. During the initial fl ight you may have to make some
minor trim adjustments.
❏ 24. Your gyro is now setup and ready to fl y. Heading Lock
mode operates completely different than normal rate gyros.
Once you place the model on the ground, you must center the
tail rotor pitch slider before starting to spool the blades up. You
will have to make some small corrections as the model begins
to lift off. Once the helicopter is in the air the gyro will hold the
tail at all times unless you make an input. If this is the fi rst time
you have fl own a Heading Lock gyro, please be patient during
the fi rst few test fl ights until you have become accustomed to
the new gyro.
GAIN ADJUSTMENTS
Start with the recommended gain setting of 45% and slowly
increase the % until the tail starts to oscillate (wag) during fl ight.
When using a heading lock gyro it is not necessary to run the
highest gain possible. Typically you will fi nd the gyro works the
best around 3%–5% lower than the maximum gain you can run.
Once you have found what you believe is the ideal gain setting,
try adding and subtracting 3% to see if operation improves.
Finding the ideal gain setting will take some experimentation.
If the gyro is allowing the tail to drift then raise the gain % and
test fl y the model.
If the tail is quickly oscillating (wagging), then lower the gain %
and test fl y the model.
TROUBLESHOOTING
The gyro indicator light does not come on. Make sure the
rudder and gyro gain control leads are plugged into the receiver
and verify the polarity of the connections. Verify that the servos
connected to the receiver operater.
❏ 20. The ATV or End Point function within your transmitter will
control the maximum pirouette rate. The ATV and End Point
functions in the transmitter have no control over how far the tail
rotor servo will travel. If you are having any binding problems
in the tail rotor linkage, then you must adjust the control ball
location on the servo arm instead. Set the ATV or End Points for
the Tail Rotor channel (Rudder – typically channel 4 for Futaba)
to 70% for left and right directions. This will reduce the pirouette
rate to a reasonable level for your fi rst fl ights. If you feel that the
pirouette rate is slow after the fi rst test fl ight, then increase the
ATV or End Point values until you have achieved a setting you
like. If you feel the pirouette rate is too quick, then reduce the
ATV or End Point values.
© Copyright 2008 HMXM1012Mnl V1.0
I cannot control the tail rotor after takeoff. Verify that the
gyro compensation direction is correct and that the drive system
and linkages to the tail rotor are in proper working condition.
The models spins out of control after lift off. Verify that the
gyro compensation direction is correct. If the compensation
direction is incorrect, the model will spin uncontrollably.
The trim changes constantly in fl ight. Verify that there are no
issues in the tail rotor drive system and the pitch control linkage.
Extreme heat near the gyro may cause some drift. Vibration will
cause the trim to shift and erratic operation of the gyro. If you
notice any vibrations in the mechanics, please address that
issue fi rst.