Revised 07/10/2012 Pyramid Models
PYRAMID MODELS
RX3S Orange Rx Flight Stabilizer Setup Guide
Click here to buy Male to Male jumper cables (you will need 3 of them)
Description:
The RX3S OrangeRx Flight Stabilizer from Pyramid Models is a 3 Axis gyro system designed to
stabilize the flight of a 4Ch Fixed Wing type Aircraft. It provides stabilization for the Aileron (roll),
Elevator (Pitch) and Rudder (Yaw) Axis. It utilizes an Atmel 168 processor and an
Invensense ITG3205 Mems 3 axis gyro chip. On the board is an Atmel AVR ISP 6 pin
type programming connection making it available for some 3rd party future upgrades or
possible upgrades from Pyramid models (No announcement of this availability or promises of
this availability to date).
The board has 3 independent gyro gain dials as well as a 3 switch Dip switch for reversing the
gyro channels.
Pre Setup:
I recommend that you fly the plane you plan to mount it on and try to achieve a mechanical setup
that yields zero or near zero subtrims as well as full servo travel (100% ATV/Travel Adjust/Endpoint Adjust). Although these 2 steps are not required, they yield less problems in the end (like
driving servos to the point of binding during flight or transport while on).
Setup:
I recommend connecting up the system prior to gyro mounting to verify it is
functioning properly.
SPECIAL NOTE: The label on the end of these Stabilizers (shown above) may NOT
be positioned or aligned correctly with the relevant pins, this may cause confusion
and incorrect results, so please double check by counting from one end or the otherfor absolute correct alignment !
Connections:
Connect the Rx to the Stabilizer as follows:
1) Use Male to Male leads purchased separately. Click Here
2) Orient the Brown or Black lead of the cable to the outside edge of the board
(shown as – on picture above) and the orange or white lead towards the inside
(shown as S on picture above).
3) Connect the Yellow AIL Input of the Stabilizer to the Aileron output of Rx
4) Connect the Yellow ELE Input of the Stabilizer to the Elevator output of the Rx
5) Connect the Yellow RUD Input of the Stabilizer to the Rudder output of the Rx
Wire the Servos to the Stabilizer as follows:
1) If you have 1 Aileron servo or 2 Aileron servos on a Y connector, connect to the Gray Ail[L] output of the Stabilizer. If you have 2 Aileron servos that are reversed from each other (connected on
two separate channels in your TX, Mixed and reversed from each other), connect one to the Ail[L]
and the other to the Ail[R]. Note that you MUST double check the Transmitter reversing before
flight! Transmitter reversing is tested without moving airplane and ONLY moving sticks.
2) Connect Elevator Servo to the ELE, GREY output of the Stabilizer If you have 2 elevator servos
and one is reversed from the other, you MUST install a separate Servo reverser supplied separately.
3) Connect the Rudder servo to the RUD GREY output of the Stabilizer.
Power:
There is a power connection available on the Orange Rx Stabilizer. So long as your RX is powered
by a 5V power, and at least one of the servo wires going from the Rx to the Stabilizer has the Center Wire, you may leave this disconnected. Most people will not need to connect anything to the
power input.. I do not know what the power tolerance is but I’m guessing they left this connection
so you could isolate Rx power from Stabilizer power by removing the center wire of the RX to Stabilizer cables then use this power connection. You will know the Stabilizer is getting power from
the Rx because the Red LED light on the Stabilizer near the Gain dials will come on when powered up.
Verifying TX reversing
If you have already flown your plane, making the above connections, you SHOULD NOT have to
change the TX reversing, but you should test this now. Turn the gain dials of the Stabilizer all the
way Counter Clock Wise (CCW). Power up Tx, then RX. Move the TX sticks and make sure all 3
axis respond correctly. Also verify none of the servos are binding. If so, fix this mechanically by adjusting the rods on the servo or surface horns.
Verify Gyro reversing.
For now, tape the stabilizer down to your plane with tape or foam tape in the approximate location
you plan to put it at. Orientate the Stabilizer with the main label facing either Up or Down. Also
face the servo connection either forward or towards the Rear. (Note, the orientation you do the
gyro reversing MUST be the same as the way you plan to permanently install as orientation affects
the gyro reversing). This will be suitable for initial testing.
Aileron:
Now with everything powered up, Turn the Aileron Dial all the way Clockwise (CW) to full gain.
Quickly Roll the airplane Right. The right aileron should have lifted when you were rolling it right. If
not, flip the AIL dip switch and try again. When you have it right, reset the AIL dial to half way (50%
gain).
Elevator
Turn the Elevator Dial all the way Clockwise (CW) to full gain. Quickly lift the tail up. The Elevator
should have moved UP when you lifted the tail. If not, flip the ELE dip switch and try again. When
you have it right, reset the ELE dial to half way (50% gain).
Rudder
Turn the Rudder Dial all the way Clockwise (CW) to full gain. Quickly push the tail right (Nose left).
The Rudder should have moved Right when you pushed the tail. If not, flip the RUD dip switch and
try again. When you have it right, reset the RUD dial to half way (50% gain).
Mounting the ORX Stabilizer
Mount the gyro in the same orientation as you did the testing. Use some double foam tape such as
Helicopter Gyro tape, or 3M Indoor/Outdoor tape (gray with red release paper). I recommend you
avoid the 3M foam tape that is white with green letters. There are other mounting methods.Do not
tape directly to foam. I recommend you glue/epoxy some plastic or something to the foam first unless you can be assured that the gyro will not come loose in flight. A loose vibrating gyro can
cause severe oscillations or an uncontrollable situation.
Double check your TX reversing and your Gyro reversing as described above!
Note, I do a gyro test and TX test before EVERY FLIGHT. It does not take much time at all! The
more you do it, the quicker it will take.
Setting Gains
At the time of the release of this revision of document, It is confirmed that the Orange Rx gain dials
are very sensitive and do not have a good linear range. In other words, from fully CCW (say 7 o’clock) to mid position (12 o’clock), the gain dials do virtually nothing. From 3 o’clock to 5 o’clock,
the gain jumps dramatically. For this reason, I recommend starting your first flight with the gains almost turned down to nil. That would be the ½ way 12 o’clock position. Moving the airplane should
barely (if at all) move the control surfaces. It should be like it was before you flew the airplane. Fly
the plane, trim it out, then land. Start to bump up the gains 1/16 to 1/32 turns at a time. Use some
common sense here. If you want to be cautious, do it 1 axis at a time. You may find that the aileron
axis is the most sensitive. You want to test for oscillations, If you get oscillations, you need to dial
the gains back. You will get the possibility of oscillations at various speeds. Ailerons tend to get the
worse in a downward high-speed dive. Elevators and Rudders vary for each plane but for a complete test, you want to fly at various speeds before you know your gains are good. On a very windy
day, you MAY see more or temporary oscillations and if so, dial the appropriate gain back. Keep in
mind that too much gain also works the servos harder and CAN cause pre-mature wear on the
motors or servo pots. Some people have reported reduced roll/loop rates when gains are higher.
Keep that in mind and do your loops/roll testing with enough altitude before building confidence.
And most important:
Have FUN. and Remeber If anyone criticizes you for using a gyro, just laugh at them when they
pack up and go home due to not being able to land crosswind, or very high winds, either of these
may result in a crashed or severly damaged model - NOT ANY MORE !
Pyramid Models has many more items on their website at www.pyramidmodels.com/shop
Pyramid Models
22 Jubilee Crescent
Arlesey
Bedforshire
SG15 6SB
England
Tel:01462 731562
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