Heli-Max HMXM1010 User Manual

You may have heard the term single axis when
speaking of gyros. Your Micro Piezo Gyro is a
single axis gyro (as are all gyros intended for R/C
use). This means that it can be used to control
only one axis. The three axes of flight are roll (the
axis about which a model banks as it turns), pitch
(simply stated, the axis about which a model tilts
downward or upward), and yaw (the axis about
which a model changes its heading). The Micro
Piezo Gyro can be

used to stabilize any of the

three axes, but for

your helicopter, you’ll want to

use it for the yaw axis.

Traditionally, model helicopter gyro devices have
been operated by an actual gyroscope—a
spinning flywheel driven by a small electric motor.
This is old technology. You’ve probably seen a
mechanical gyro on one of those educational
television programs showing the development of
rockets for early space flight! Your Micro Piezo
Gyro uses the latest technology with a piezo­electric crystal. A piezo-electric gyro has no
moving parts, is much more compact, lighter,
more durable, and uses much less battery power
than a mechanical gyro. Further, a piezo-electric
gyro offers faster response time and more
accurate control than a mechanical gyro.

The way a gyro works is by sensing motion about
the axis which it controls (the yaw axis for your
helicopter), and sending a signal to your servo
instructing it to steer the tail in the opposite
direction, thus preventing unwanted rotation of the
tail. The end result is a much more stable tail and
a helicopter that is easier to control! This gyro
does not, however, return the model to its starting
position. Don’t worry, the gyro knows the
difference between this unwanted rotation and
your control inputs—you’re still the one in control!

Follow these instructions so your gyro will operate
correctly.

PRECAUTIONS

Before you mount your gyro, keep these things in
mind.

❏ 1. You can mount the gyro anywhere on your

helicopter as long as its rotation axis (noted on
the label on your gyro) is lined up with whatever

axis you wish to control. In the case of your
helicopter, this is the yaw axis.

❏ 2. Although your piezo gyro is mounted in a

protective case, as with any electronic device, you
must protect it from vibration or shock. Mount your
gyro in a strategic location where it is not likely
to hit the ground or be hit by parts of your
helicopter that may break away in a crash (such
as the battery pack). Most helicopters have a
location intended for mounting the gyro. Use at
least one layer of 1/8" (3mm) double-sided foam
tape to mount your gyro and make certain none of
the surfaces of the gyro contacts any part of the
helicopter. Clean the mounting surfaces with
alcohol so your gyro will remain secure. Some
modelers prefer to cover the gyro with foam or
other protective material to provide extra crash
protection. We recommend this also.

❏ 3. You may use a servo extension cord if the

cord on your gyro is not long enough to reach
your receiver.

❏ 4. Piezo crystals are sensitive to temperature

changes. It is important that you mount your gyro
in a ventilated area to avoid excess heat buildup
during operation. Avoid mounting your gyro close
to the engine or muffler, or locations on your
helicopter that do not provide any air flow.

CONNECT YOUR GYRO

❏ 1. Your Micro Piezo Gryo comes with a Futaba

®

brand “J” style connector that plugs into your
receiver. If you own a Futaba radio control system
proceed to step 3. If you own another brand of
radio with a different type of connector, you may

have to modify the connector on the gyro to match
your radio, and the connector on your servo that
plugs into the gyro. Usually, all that is required is
to carefully shave the key from the gyro connector
so it will fit into your receiver and rearrange the
wires so the polarities match your radio system. In
some cases, you may have to cut your servo cord
and the cord on the gyro, then solder on Futaba J­connectors.

❏ 2. If you’ve modified your connectors, make

certain the wiring order on your servo connector

and the gyro connector is the same as the wiring
order on the Futaba connector. Study the
diagram. The positive (+) wire is in the center, the
negative (-) wire is on the side opposite of the
key on the connector, and signal (s) is on the side
of the connector nearest the key. WARNING!
Failure to match polarities on any connector may
damage your gyro and will void your warranty.

❏ 3. Plug the connector coming from the gyro into

the channel in your receiver you intend the gyro to
assist (in the case of your helicopter, the
rudder/tail rotor channel).

❏ 4. Make sure the wiring order on your tail rotor

servo is correct. Connect your tail rotor servo to
the slot on the gyro marked servo.

MICRO PIEZO GYRO

INSTRUCTIONS

Congratulations and thank you for purchasing the
Heli-Max™Micro Piezo Gyro for R/C helicopters.
A gyro stabilizes the tail rotor control on your
model helicopter. Of all the controls on a model
helicopter, the tail rotor is the most difficult to
master. In fact, flying an R/C helicopter without a
gyro is nearly impossible, or extremely difficult at
best. Even an expert wouldn’t be caught without
a gyro and a beginner would probably never get
off the ground without one. Someday you may
wish to find out just how difficult it is to fly a model
helicopter without a gyro—just turn off your gyro
and try to establish a hover—you’ll see! Don’t try
this until you have mastered hovering!

DETERMINE THE CONTROL DIRECTION

❏ 1. Turn on your transmitter and receiver. Give

your tail rotor left input from the control stick on
your transmitter. Note which way the arm on your
tail rotor servo responds.

❏ 2. Holding the gyro in your hand, quickly turn it

to the right about its rotation axis (clockwise). The
tail rotor should respond in the same direction it
did when you gave it left input from your
transmitter (now you can understand that the tail
rotor servo will give left input when the gyro
moves to the right, and vice versa). If your servo
responded with a right control input when you
rotated the gyro to the right, your gyro is working
in reverse so you must flip it upside down. Try
again. Now your servo should give a left response
when you move the gyro to the right. All you have
to do is mount your gyro upside down in your
helicopter!

MOUNT YOUR GYRO

❏ 1. Mount your gyro using the double-sided

foam tape included. Make sure it is secure by
gently tugging on it. If your gyro comes loose
while you are flying, you will notice erratic tail
operation. Land immediately and turn off the
engine.

❏ 2. Confirm that you have mounted your gyro in

the correct orientation. Turn on your transmitter
and receiver. Quickly rotate the nose of your
helicopter to the right and observe the direction
that the tail rotor servo responds. The tail rotor
servo arm should rotate in a direction that will
provide left tail rotor input when you rotate the
nose of your helicopter to the right. If it does not,
you have mounted your gyro upside down.
Remove your gyro, flip it upside down, and
remount it.

CENTER YOUR SERVO

❏ 1. Temporarily disconnect the gyro from your

helicopter and connect the tail rotor servo to your
receiver. If your helicopter has not already been

flown and you have not already done so, center
the tail rotor trim on your transmitter. Mount your
tail rotor servo arm on your tail rotor servo so it is
centered. Adjust the tail rotor control rod so the tail
rotor blades have the correct amount of pitch as
described in your helicopter instruction manual.
Set the ATV’s on your transmitter or mount the tail
rotor control rod to your tail rotor servo arm so you
will get full control throw when you move your
transmitter control stick all the way to the right and
all the way to the left. Hint: For the best servo
resolution (smoothness), connect your tail rotor
control rod to the servo arm where you can get as
close as possible to 100% ATV. Reconnect your
gyro to the receiver.

❏ 2. Reconnect your gyro to your receiver and

your tail rotor servo to the gyro. Use a small
phillips screwdriver to temporarily set the +gain-
dial inside the gyro to approximately 50% (we’ll
explain this function in the next section). The gain
control dial has a total range of a little less than
270°, so turn the dial all the way to the right
(clockwise-no gain), then turn your screwdriver
about 140° to the left (toward +gain). Do not force
the dial past its stops.

❏ 3. Note the position of your tail rotor servo arm

now that you have centered it. Turn on your
transmitter and your receiver. Observe the tail
rotor servo arm. If it rotates, use a small phillips
screwdriver to adjust the center dial inside the
gyro until your tail rotor servo arm returns to
center. Now your tail rotor servo is once again
centered. Later, if you choose to adjust the gain
control on the gyro, you may have to readjust the
center dial to keep your tail rotor servo centered.

SET YOUR GYRO SENSITIVITY (GAIN)

The sensitivity, or gain control, determines how
much effect your gyro will have on your tail rotor.
The more sensitive you have set your gyro, the
more stable your tail will be, but this may reduce
aerobatic capability where tail rotor quickness is
desired.

❏ 1. If you are a beginner and are not yet able to

establish a hover, for now you’ll just have to
estimate the sensitivity required. 50% is a good
starting point. You’ve already been instructed to
set the +Gain- control dial to 50% so you’re ready
to go. Read the following instructions to know how
to fine tune your gyro when you become more
proficient at hovering.

❏ 2. Before you begin hovering, make sure your

receiver and transmitter are turned off and let your
helicopter sit outside for a few minutes. This will
allow the gyro to become acclimated to the
temperature and is necessary due to the
temporary effect the temperature change can
have on your gyro.

If you are able to hover, perform the following
exercises to fine tune your gyro sensitivity.

❏ 3. Turn on your transmitter and receiver.

Confirm the operation of your gyro. Start your
engine and lift your helicopter into a hover. Give
some tail input to test the tail response. If the tail
responds faster than you prefer or is not stable,
land your helicopter and increase the gain dial on
the gyro. If the tail hunts or wags back and forth,
or does not respond as quickly as you would like,
land your helicopter and reduce the gain dial.
Make adjustments in small increments. Lift your
helicopter into a hover. Continue hovering and
adjusting the gain control until your helicopter
handles the way you prefer.

❏ 4. Now adjust your gyro for forward flight. The

setting you achieved in a hover should work for
general sport flying, but if you intend to perform
fast forward flight and aerobatics, you may require
a less sensitive gain setting. To test this, take the
heli up and fly around. The same as in a hover, if
the tail wags or bounces back and forth, the
sensitivity is too high. You may have to
compromise between your hovering requirements
and forward flight requirements to achieve a gyro
setting that is acceptable for both flight modes.
Test and adjust your gyro for both hovering and
forward flight until your helicopter handles the way
you like.

❏ 5. As the temperature changes, the centering

of

your servo may shift (due to the gyro’s

temperature

sensitivity). Use the Center control
dial on your gyro to maintain servo centering as
required.

TECHNICAL SPECIFICATIONS

Power Supply: 3.3-7.0 volts DC
Current Drain: approximately 35mA
Weight: 0.49oz (14g)
Dimensions: 1.1x1.1x0.6in (28x28x16mm)
Temperature
Range: 50° - 95° F (10° - 35° C)

ONE YEAR WARRANTY STATEMENT

*USA and Canada Only

Heli-Max warrants this product from defects in materials
and workmanship for a period of one year from the date of
purchase. During that period, Heli-Max will, at its option,
repair or replace without service charge any product
deemed defective due to those causes. You will be
required to provide proof of purchase (invoice or receipt).
This warranty does not cover damage caused by abuse,
misuse, alteration or accident. If there is damage
stemming from these causes within the stated warranty
period, Heli-Max will, at its option, repair or replace it for a
service charge not greater than 50% of its then current
retail list price. Be sure to include your daytime telephone
number in case we need to contact you about your repair.
This warranty gives you specific rights. You may have
other rights, which vary from state to state.

For service on your Heli-Max product, warranty or non­warranty, send it post paid and insured to:

HOBBY SERVICES

1610 Interstate Drive

Champaign, IL 61822

Attn: Service Department

Phone: [phone]:00 A.M. - 5:00 P.M. Central Time M-F

E-Mail: [e-mail]

We can also be reached on the internet at:

www.hobbies.net/helimax

*For warranty and service information if purchased outside
the USA or Canada, see the additional warranty
information (if applicable) or ask your retailer for more
information.

Entire Contents © Copyright 1998

Printed in USAHMXZ4911 For HMXM1010