Lemon Stabilizer Plus User manual

StabPlus Quick Start v1
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Lemon Stabilizer Plus - Quick Start Guide
This Quick Start guide outlines the basic setup of the Lemon Stabilizer Plus with a generation 2 or later Spektrum
transmitter. For other transmitters and additional details see:
Essential Instructions
https://www.rcgroups.com/forums/showatt.php?attachmentid=11910025&d=1554438806
and the Reference Guide
https://www.rcgroups.com/forums/showatt.php?attachmentid=9835599&d=1488573620
Important: As supplied, stabilization is turned OFF. To turn ON, see table below.
1) Set up a new model on your transmitter. It must be set up as a conventional model with ailerons (single or
dual) and normal rudder and elevator. Even if your model has a V-Tail or has Elevons (e.g. is a Delta), do not
do any V-Tail or Elevon mixing in the transmitter.
2) Set the 3 white switches 4, 5 and 6 as shown in the table below. A pin is a good tool to flick the switches On
or Off. Make sure they are firmly at one side or the other.
Model configuration
Aircraft type
Switches
Wing
Tail
4
5
6
1x Aileron servo, conventional tail
Normal
Normal
ON
ON
Off
2x Aileron servos, conventional tail
Dual Ail
Normal
ON
ON
ON
1x Aileron servo, V-Tail. Tail servos connect to E and R
Normal
Normal
Off
ON
Off
2x Aileron servos, V-Tail. Tail servos connect to E and R
Dual Ail
Normal
Off
ON
ON
Elevons or Delta wing. Servos connect to A and E
Normal
Normal
ON
Off
Off
The photo above shows how the output pins support the various functions.
Channels 1 - 4 are the primary controls, in order: Throttle, Aileron, Elevator, Rudder.
Channel 5 (Gear) controls Stabilization mode and is not to be connected to a servo.
Go to Channel Assign, NEXT, and set 5 Gear: to a suitable three-position switch, e.g. B or D.
Channel 6 (Aux1) may be used for Retracts or for the second servo in a dual Aileron setup.
Channel 7 (Aux2) can support Flaps and doubles as the Bind pins.
Channel 8 (internal to the StabPlus) is used for Master Gain (knob) on an 8-channel transmitter.

StabPlus Quick Start v1
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3) Set the 3 rotary stabilizer gain resistors (“pots”) to about the 12 o’clock position.
The illustration is of a top pin StabPlus. The top pin and end pin stabilizers are
identical apart from the pin type.
This is a good safe initial setting for almost all models. It will normally give modest
but noticeable stabilization.
4) Mount the StabPlus securely using the supplied double-sided tape on either a
horizontal or vertical surface facing along the centreline of the fuselage with the pins to the rear. The case
edge should align with the fore and aft direction.
Connect all the servos and the speed controller. For any orientation except Upright, it is essential to reset
the stabilizer level, as described briefly under Stabilizer Setup at 6), point 3 below. Full details are provided
on pages 11 and 12 of the Essential Instructions.
5) Bind the stabilizer to the transmitter and set Failsafe.
1. Put a bind plug on the Bind/channel 7 pins.
2. With the transmitter OFF, apply power to the stabilizer. The
Red and Green lights (and the Red internal light) should
flash rapidly to indicate Bind Mode.
3. Turn ON the transmitter in Bind Mode. The transmitter
should be separated from the stabilizer by 1-2m (3-6 feet).
In some cases, even more separation may be needed for
binding.
4. Wait until the transmitter indicates “bind complete” and the rapid Red/Green flashing stops.
5. Wait up to 20 seconds or so for the initialization process to complete, as indicated by: Green/Blue lights
no longer flashing.
6. Move the relevant transmitter sticks and switches to the desired failsafe positions.
7. Press the stabilizer button briefly (less than 1 second) and release. If the green light next to the button
stays on, failsafe is set.
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It remains set unless you do a rebind.
8. Power down the stabilizer and transmitter. Don’t forget to remove the bind plug.
To test the bi nd, tur n on t he transm itter and then the s tabi li ze r. Wai t at le ast 20 seconds for
initialization to complete. Check the operation of the Stabilizer mode switch with the sticks left at
neutral:
• Position 0: OFF – Red/Green solid (or flickering very slightly); no servo movement when model is
rotated.
• Position 1: Gyro – Green ON solid, Red OFF; servos move briefly when model is rotated.
• Position 2: Autolevel – Red and Green lights flashing alternately; aileron and elevator servos stay
deflected when model is not level, rudder servo moves briefly when model is rotated (yawed).
1
If the BLUE light comes on, you have held the button too long and selected Always-ON. Press the button again for more than 1 second to
cancel this, then to set failsafe, press briefly (less than 1 second) while holding the desired control inputs.

StabPlus Quick Start v1
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6) Stabilizer Setup.
Always remove the propeller or disconnect the motor before working with the battery plugged in.
1. Place the model on a firm base and in a “level flight” attitude – typically 2-3 degrees nose up.
2. With the receiver already bound, power up first the transmitter and then the receiver.
3. As soon as the Green/Blue LEDs start flashing, toggle the switch that controls Stabilizer Mode. “Toggl ing ”
means rapidly flicking the switch from one extreme to the other at least 3 times. If successful, first the
red LED on top of the unit will light, then the green light will flash four times
4. Wait for the receiver to complete its initialization. Do not move the model during this time –
approximately 10-15 seconds.
5. With the stabilizer mode set to OFF (Red /Green ON solid), verify that all control surfaces travel in their
correct directions when the transmitter sticks are moved. If necessary, change the relevant Reverse
setting under Servo Setup in the transmitter. At this time check that all control surfaces are centered.
6. Set the stabilizer mode to Autolevel (Red/Green alternately flashing slowly). Rotate the model about the
pitch and roll axes and watch for the ailerons and elevator to deflect and stay deflected when it is not
level.
7. The directions of the stabilizer action on the aileron and
elevator axes MUST be as follows:
If the model is rolled to the right: right aileron goes DOWN
and the left UP to level the model.
If the nose of model is pitched down: elevator goes UP to
restore the model to level flight.
The rudder is also stabilized but reacts differently:
If model is yawed (rotated) to the right, the rudder pulses
LEFT momentarily to resist the displacement, then returns to
neutral.
If any response is incorrect, use the appropriate switch J1, J2 or J3 to reverse the action and test again. The
labels On and Off have no specific meaning for these switches.
7) Transmitter Setup.
1. If available, set Master Gain to the midpoint (i.e., 0% on the transmitter’s monitor screen for channel 8).
If your transmitter has less than eight channels, Master Gain is fixed at 1x, which is 0%, and you can skip
this.
2. Check that the flight control trims are set to zero. If necessary, use a little Sub-trim to align the servo
arms at right angles to the pushrods. Adjust mechanical settings to center the control surfaces.
3. Te st fai lsafe by turning off the transmitter with the motor running and the prop removed or the model
restrained. (Do this failsafe test on the ground, NOT in flight!).
Make sure you know how to find the Stabilizer Mode switch without having to look down at the transmitter
and that you know how to turn it OFF quickly.
It is recommended that you set up Dual Rates on the transmitter with Low Rate being about 70% and High
Rate 100%. Use mechanical adjustments and/or servo travel to set control throws to those recommended for
the model.
You may also wish to add 20% Expo, or somewhat more, to soften control responses around neutral, but
keep in mind that stabilization has an expo-like effect.

StabPlus Quick Start v1
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8) Flying
1. Carefully recheck the directions of BOTH control movement AND stabilizer action – a mistake here can
have serious consequences! In summary: correct response to stick input is set in the transmitter, correct
response to a disturbance is set in the stabilizer.
2. Set Stabilizer Mode switch to OFF (Position 0). Red/Green LEDs are solidly on. Select Low Rate.
3. Ta ke o ff and cl im b to a safe he ig ht.
4. Turn ON Gyro mode (Position 1). Expect Gyro mode to cause the model to fly more smoothly, resist wind
gusts, and be somewhat less sensitive to control inputs than with the stabilizer OFF. If there are any
unexpected reactions, immediately turn OFF the stabilizer (Position 0) and land to trouble-shoot.
5. If you see oscillation on any axis, slow down and land (or slightly turn down Master Gain, if you have it).
Turn the relevant pot(s) down (CCW) by an “hour” or so to reduce stabilization. To increas e stabil izati on
on any axis, turn up the gain. See Adjusting Gain on page 10 of the Essential Instructions for detail on
adjusting gain and the Reference Guide for further advice.
6. Switch to Autolevel mode (Position 2). In Autolevel mode, you should find the model much more docile,
with a strong tendency to return to level when you neutralize the sticks. You will still have control, but
turns may require significantly more input and maximum bank and pitch will be limited. To increase
control authority, you can use High Rate and/or change to Advanced Autolevel mode in the stabilizer
configuration, which allows steeper bank angles (see Essential Instructions page 13). Be ready to switch
to OFF or Gyro if you encounter a problem.
If the model (with throttle set appropriately) does not maintain level flight in Autolevel mode, switch to OFF
or Gyro mode, land and reset Stabilizer Level and Stick Neutrals. Level is set by a toggle gesture during the
initialization period while the Green/Blue LEDs are flashing. Stick neutral is set by a toggle gesture after the
initialization period is complete. This is explained in detail on pages 11 and 12 of the Essential Instructions.
Variations of the StabPlus
The top pin LM0043 and end pin LM0044 are identical apart from the pin type.
When purchasing from the website, if they have a D suffix they are specified for a 5V supply, E and T suffix
versions can be used up to 8.4V. Early models with no suffix can be used up to 7.2V.
NOTICE
This guide is provided to help you quickly set up and use the Lemon Stabilizer Plus 7-Channel Integrated
Receiver. The authors are not associated with Lemon Rx and this is not a Lemon Rx publication.
You can freely quote from, redistribute and/or modify this guide; in doing so please acknowledge the source
and any changes.
The guide is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details. In using this guide, you agree that you accept all responsibility.
Additional information and discussion about the Lemon StabPlus is available in “The NEW official Lemon
Stabilizer Plus thread”.
The Lemon RX website is here.
JJ604 and Daedalus66 - February 2020