Futaba G501 User Manual

formance. To obtain full performance from this rate gyro and
also for safety, please read this manual before use. After read­ing this manual, please retain it for future use. Also read the
instruction manual supplied with the digital proportional radio
control set, model kit, and engine.

D60510

Thank you for buying a Futaba FP-G501 piezoelectric rate
gyro.
The FP-G501 is used with model helicopters and fixed wing
aircraft when wanting to suppress changes in the aircraft's atti­tude by changes in air currents, engine torque, etc.
The FP-G501 features a very fast response speed and high
gyro sensitivity made possible by using a piezoelectric ceramic
element as the angle sensor. In the past a rotating motion was
used which resulted in a wide dynamic range that allowed con­stant control of the rotating speed which was much slower per-

NOTE:

to obtain maxima performance. If used with another servo,
the FP-G501 may not operate satisfactorily, or yield maxi­mum performance.

The FP-G501 should be

used

with the FP-S9203

CONTENTS

1.FEATURES

2. SET CONTENTS

3. MOUNTING AND CONNECTIONS

4. SENSITIVITY ADJUSTMENT

5. ADJUSTMENT PROCEDURE

6. USAGE PRECAUTIONS

7. RATINGS

8. REPAIR SERVICE

IMPORTANT:

For safe use, read the items indicated
tion mark especially carefully.

by the

following cau-

I ;Caution mark

"All, or part. of this manual may not be reproduced without prior permission.
"The contents of this manual are subject to change without prior notice
"This manual has been carefully written, but if you find anything that you do not
understand or that is incorrect, please contact Futaba.
"Futaba is not responsible for use of this gyro by the user.
"Futaba" is a registered trade mark.

• Minimizes changes in an aircraft's attitude by wind, etc.

The especially high frequency response of the piezoelectric
gyro allows an increase in gyro sensitivity. The original ability of
a gyro to suppress changes in an aircraft's attitude due to wind
and engine torque changes and other unexpected phenomena
has been increased substantially.

• Angular acceleration commands used.

To take advantage of the wide dynamic range of the piezoelec­tric gyro, angular acceleration commands are used. The trans­mitter stick operating angle becomes the aircraft command for
angular acceleration and the aircraft rotating speed is propor­tional to the stick operating angle that is obtained while main­taining stabilization performance. This is the greatest merit of
the piezoelectric rate gyro over conventional gyros. Fixed rota­tion of the aircraft can be commanded by the transmitter stick
operating angle.

• Piezoelectric gyro drift cancellation.

Deviation of the gyro from the direction to be maintained (neu-

tral) is called drift. When the power is turned on, the FP-G501

senses this drift and automatically compensates it during gyro
operation. Therefore, do not move the aircraft for four to five
seconds after turning on the power.

• FP-S9203 high response servo.

To take advantage of the excellent response of the FP-G501
and to extract the ultimate performance of the piezoelectric
gyro, a FP-S9203 coreless servo has been designed for this
purpose.

• Sensor vibrationproofing.

A special suspension is built into the gyro to vibration-proof the

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sensor element itself. The sensor is protected against un­wanted vibrations around the sensor shaft while maintaining
high response.

• Simple sensitivity adjustment.

High side and low side sensitivity can be easily adjusted from 0
to 100% each by means of control box trimmers.
The sensitivity can also be adjusted from the transmitter.

(Terminology)

Piezoelectric gyro

Whereas the conventional gyro uses a rotating body to sense
angular acceleration, the piezoelectric gyro uses a piezoelectric
ceramic element. When rotation angular acceleration is applied
while the piezoelectric ceramic element is vibrating, force propor­tional to the rotation angular acceleration is generated in the di­rection perpendicular to the direction of vibration. The piezoelec­tric element is flexed by this force and the angularacceleration is
sensed by extracting the change of this vibration as an electric
signal. The gyro is called a piezoelectric gyro because of this
principle. An amplifier processes the sensed signal, together with
the control signal from the transmitter, and controls the servo.

Gyro

Servo

Accessories

Single set

FP-G501

Small screwdriver (for adjustment)
Double-sided tape (for gyro mounting)

Set w/servo

FP-S9203

Mounting precautions

The amount of improvement of gyro performance
has a considerable effect on the fuselage vibration
level or the size, type, linkage method, looseness,

etc. of the tail rotor.
The use of a tale rotor drive tube or other part with a high
torsion performance for the tail drive is recommended.
Since a higher gain than usual can be used then the tail
rotor is more effective, the load on the tail is also greater.
Therefore, take the strength of the tail into account during
inspection and adjustment.

Gyro mounting

Mount the gyro so that it is on a straight line with the axis you
want to stabilize as shown in the mounting example

In this case, stick thick double-sided tape (use the

double-sided tape supplied with the gyro) to the

entire bottom of the sensor so that unwanted vibra-

tions of the fuselage are not directly transmitted to

the sensor and the gyro is fastened firmly to the

fuselage.

Control amp mounting

Wrap the control amp in sponge and mount it the same as the
receiver.

Mounting examples

Control box mounting

Modify the aircraft to match the mounting position hole and
mount the control box, or fasten the control box to the aircraft

with double-sided tape.

Mount the control box where vibration and exhaust

are small.

CONNECTIONS

Control amp

Gyro sensor

Adjust low sensitivity with the "L"
side sensitivity trimmer and high
sensitivity with the "H" side
sensitivity trimmer. When the
direction of the sensitivity switch is
opposite, set the direction using the
reverse function for gyro channel.
This is usually CH.5.

Servo

*Servo controlled by gyro.

Gyro output polarity switch

Connector

A

(black)

Connector B (red)

"When adjusting the linkage, always check the
polarity of the gyro output. If the polarity is opposite,
switch it with the direction select switch.

PRECAUTIONS WHEN TURNING ON THE RECEIVER POWER

Never move the aircraft for four or five seconds
after turning on the gyro power (shared with re­ceiver).

Since initialization is automatically performed inside the
gyro immediately after the power is turned on, if the aircraft

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is moved at that time, the neutral position will change. In this
case, turn on the power again.
At this time, the rudder servo (servo controlled by gyro)
moves to the home position after the servos on the other
channels, but this is normal.

To receiver rudder channel

(helicopter yaw axis stabilization)

To receiver channel 5
(sensitivity switching channel)