The G-400 is a single setting unit, while the G-450 offers infinite adjustment to optimize both hovering and forward flight. Both the G400 and G450 utilize a state-of-the-art integrated design and performance simular to their previous JR NEJ-900 Piezo gyro.
Both gyros offers a true linear response of up to 720 degrees per second. In addition, both are approximately 10 times more sensitive than mechanical gyros. Since the response time is faster than any current mechanical type gyro, there is a substantial gain in performance. Unlike standard mechanical type gyros that use a motor, fly weights, bearings, etc., Piezo gyro systems are totally free of moving parts that in time wear out, giving nearly unlimited service life.
The Piezo gyros environment is very different than that of a mechanical type gyro system. Many current settings, including the travel volume, exponential, dual rates and tail rotor revolution mixing values, must all be changed from their previous normal settings in order to achieve the correct tail rotor / control surface response and maximum performance.
If you have been using a mechanical gyro, it is highly recommended that you first re-adjust throws and linkages as recommended in the instructions.
According to JR, in the event of hooking the system up incorrectly, no damage will occur to any of the radio components. Of course - I'm pretty sure this does not apply to re-wiring the gyro for other systems.
Servo Selection
The G400-450 Piezo gyros offer greatly improved response time, sensitivity and performance as compared to some other Piezo gyros. However, in order to realize these improvements, great care and consideration must be taken in the selection of the servos to be used. In general, the quicker the transit time and the more accurate the centering tendencies of the servo, the better the gyro will perform.
If a servo with a slow transit time is used, in actuality the G450 may become too quick for the servo, resulting in a "wag" or hunting situation which will require the user to reduce the percentage of gain. This reduction in gain will also reduce the holding power and therefore, the performance of the gyro. There are three important points that must be considered when deciding on the correct position you should mount the piezo gyro;
#1 Heat - The Piezo sensor is sensitive to drastic temperature changes, in some cases a neutral drift will occur. When mounting the Gyro Sensing Unit, be sure it is located away from the engine and exhaust system so a minimum of heat will transfer to the Gyro Sensing Unit from these or any other helicopter parts that might change temperature during operation. Also, when subjecting your helicopter to temperature differentials, such as going from your warm car to the cold outside, allow the gyro's temperature to stabilize for about 10 minutes before flying.
Also note that with the use of fuselages, heat can circulate throughout the radio compartment. It is important to have adequate ventilation, both incoming and outgoing, to allow the hot air to escape during operation.
#2 Vibration - The Piezo gyro is 10 times more sensitive to rotational motion than a standard mechanical type gyro . Plus, it has a 10 times faster response time (the time it takes the gyro system to react to motion). Because vibration is motion, the Piezo gyro senses even minute vibrations and acts upon them (sending the servo an opposing command) 10 times faster than a standard gyro. It is, therefore, important to reduce the vibration of your model to a minimum by making sure that everything is balanced, straight and properly adjusted. The Gyro sensor should be mounted away from inherent high vibration areas, such as the engine.
#3 Location - The Gyro Sensing Unit should be mounted as close to the center of gravity (normally the main shaft) as possible. Some model manufactures provide mounting bases near the main shaft. Use them only if they are positioned away from heat-generating sources. While it is not mandatory to mount the gyro directly under the main shaft, you should attempt to do so if possible. Keep in mind that excellent results may also be obtained by mounting the gyro in the forward portion of the model such as in the radio compartment.
Helicopter Installation
It is important that you mount the gyro with the label on top of the unit facing upward. The G400-450 Piezo gyros gives true linear feedback and response of rotation rates up to over 720 degrees per second (standard gyros are limited to approximately 250 degrees per second). Thus, the gyro is still sensing at high rotation rates, giving appropriate feedback to the servo. This allows for more consistent pirouettes in the wind and improved 540 stall turns with aggressive stops.
Because of this high rate of rotation sensing, the adjustment values such as; travel adjust, dual rates, exponential, tail rotor compensation, will be very different than what you might be used to with mechanical gyros. The following is a setup and adjustment procedure that must be followed to achieve the highest level of performance from your system.
Set-Up
Step 1: Unhook the tail rotor linkage from your rudder servo and swing the servo arm out of the way. Lightly grasp the tail rotor pushrod at the servo end and move it through its entire pitch range. The tail rotor linkage should move through its entire range smoothly with very little friction and no rough spots. If needed, adjust the linkage system until this is achieved.
Step 2: On your transmitter, set all rudder trimmers (sub-trim, trim offset, mechanical trim, etc.) to zero. Set the throttle-pitch stick at exactly the hover position (standard hover position is 50%, switchless inverted (Mas Tech) position is 75%). Turn off or zero out both the revolution mixing up and down and the acceleration mixing.
Step 3: Turn on your receiver and allow the helicopter to remain totally motionless for 3 seconds. This procedure is necessary to allow the gyro time to establish and record the center or neutral positions.
Step 4: Remove the servo arm and replace it so that it is exactly 90 degrees to the tail rotor pushrod. You may find that the splines in the screw output shaft are just offset enough on your servo arm so as to not allow 90 degree positioning. Rotate the servo arm to another position and try again. Find the spline that is closest to 90 degrees and secure it in place with the provided screw.
Control Rod Ball Placement - For best performance, attach the tail control rod ball to the servo arm at a distance of approximately 15-18mm from the center mounting screw of the servo arm. The performance of Piezo gyros will be greatly reduced if the tail control rod ball is attached at a distance of less than 15mm.
Step 5: Be sure the rudder servo is moving in the proper direction. A right servo command should move the nose to the right. Seek help from a qualified pilot if necessary.
Step 6: Move the tail rotor stick to the right and note the direction the rudder servo moves (clockwise or counterclockwise). Now pick up the helicopter and quickly move the nose to the left. The servo should move in the same direction. If it moves in the opposite direction, switch the small reverse switch located on the gyro sensor in the opposite direction.
Step 7: To verify that the gyro is compensating in the correct direction. With a quick motion, rotate the nose of the helicopter to the left while viewing the servo arm/tail rotor blades. If correct, the leading edge or front of the tail rotor blades should pitch to the left as shown. Reverse the direction of the gyro compensation if necessary using the Direction Reversing Switch located on the Sensor Unit.
Overdriving the Tail Rotor

 

As the transmitter gives a command to the servo to find a specific position, such as full right rudder. The gyro senses the right rotation and gives the opposite command (left) to the servo. The final servo position (and hence the rotation rate) is based on the transmitter's command versus the gyro's gain setting versus the rotation rate.
In order to get really rapid rotation rates with some helicopters, it may be necessary to use a travel adjustment that, on the ground, actually exceeds the mechanical limitations of the tail rotor mechanism. In flight, the Piezo gyro will reduce the travel so binding will not occur. But be very careful on the ground to ensure that you don't give hard over rudder commands to prevent binding.
Transmitter Adjustments:
Travel Adjust
Set the rudder travel adjustment to maximum right and left. If you are using a JR PCM-l0S, l0SX, l0SXll or l0X, set this adjustment to 150% 1eft and l50% right. Please note that this may overdrive the tail rotor mechanism on the ground. However, in flight, the gyro will reduce the throw preventing binding at the extremes.

Dual Rates - The recommended starting points for dual rates are:
Maneuver Dual Rate Flight Mode
Hover 80% Normal
540 Stall Turn 100% Flight Mode 1
Standard Aerobatics 80% Flight Mode 2

After some experience and flight time is gained, these values can be adjusted to suit your preference. It is recommended to adjust the dual rate values to obtain the desired maximum rotational rate during a maneuver.
Example: If 100% dual rate yields too high of a rotation rate in the 540 stall turn when the rudder stick is fully displaced, reduce the dual rate value until the desired rotation rate is achieved.
Exponential
Because large servo travel is utilized, such as 150% left & 150% right, the control sensitivity around neutral is very high. Exponential is recommended to reduce this over-sensitivity around neutral.

Recommended expo settings:
Maneuver Exponential Value Flight Mode
Hover 30% Normal
540 Stall Turns 30% Flight Mode 1
Std Aerobatics 40% Flight Mode 2

After some experience and flight time is gained, these values can be changed to suit your preference. It is recommended to use exponential to adjust the control sensitivity from neutral to approximately 1/3 stick position.
Revo Mixing
The G400-450 actually increases the total servo travel by approximately 35%. Compared with previous gyro systems, the Piezo gyro will require that you reduce the revo mixing, stunt trim, and +/-P values by approximately 35%.
Stunt Trim
Test fly and adjust until the tail follows exactly behind the body in fast forward flight, full throttle.

G-450 Remote Gain Control Set-Up JR PCM10, 10S, 10SX, 10SXII, l0X

The Remote Gain Controller allows adjustments to be made from the transmitter. When using JR PCM l0 Series radio, plug the Remote Gain Controller's AUX connector into the receiver's AUX 3 jack. This will allow gain control adjustments to be made in Code 44 of the transmitter. See the radio's instruction manual for further information.
Enter Code 44 in the transmitter. Press the ACT on the screen to activate the gyro sensing adjustment. By flipping the AUX 3 switch on the upper right of the TX, the arrow moves from one gain position to the next. The values can be changed by pressing the + or - key. For hover (normally the top value), set a starting value of 90%. For forward flight, set a value of 70%. See the screen example. Please refer to your radio's instructions for further information.

Remote Gain Control Set-Up JR XP8103

The JR XP8103 offers two different types of gyro sensitivity adjustments, manual or automatic. This feature gives the user the choice of selecting gyro sensitivity manually through the Rudder D/R Switch or automatically through the Flight Mode Switch. When using this feature, connect the remote gain controller AUX connector (white) into the AUX 2 channel of the receiver. Next, select either the manual or automatic gyro sensitivity feature and adjust the gyro rate values as shown in the illustration.

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