Adding Auto Leveling and Return-to-Home to a Lemon 7 channel stabilizer. - RC Groups
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May 21, 2015, 07:32 AM
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Mini-HowTo

Adding Auto Leveling and Return-to-Home to a Lemon 7 channel stabilizer.


What is it?

This project adds automatic self-leveling (like the Eagletree Guardian 2D mode) and automatic return to the launch point using a GPS receiver to the Lemon 7-channel integrated DSMX receiver/stabilizer. It takes about 5 minutes and requires no modifications or soldering. The end result is a first class, very compact and lightweight full range DSMX receiver with excellent selectable variable rate stabilization for normal flying, plus an optional “panic mode” self leveling or return to home if you lose control or lose the model.

The first picture shows what the final unit looks like - with the optional Lemon satellite attached.

Background

The Lemon 7-channel 3-axis stabilizer has proved an outstanding rate stabilizer integrated with a first class DSMX receiver. For Spektrum transmitter users, particularly those with an 8 channel or better transmitter, it offers excellent basic stabilization in windy conditions, including in-flight adjustable gain, in a very compact, simple and low cost package. Lemon are working on a much more advanced version which is to incorporate telemetry and a 9 axis stabilization system. However in the meantime it proved possible to add auto-leveling and automatic Return to Home using an add-on Turnigy T1000FC stabilizer. (Footnote 1) Such a contraption is particularly attractive to those of us flying motor gliders at long range whose eyesight is not what it was. Get disoriented or lose the model and you can automatically level it and circle until you catch sight of it again or even get it to obediently come back to where you launched it, maintaining height all the way. It works well but it is clumsy and requires the use of an external switch or twin receiver switch to disconnect the TF1000FC when you want normal Lemon stabilization or no stabilization at all.

I came across another extremely attractive option. This is the very small and light Bigaole BGL-6G-AP. Bigaole make a range of model stabilizers.

http://www.bglmodel.com/contents/7/78.html

See Picture 2 for what is in the package.

There are a number of Internet vendors selling it. I got mine from Michael at Mad RC who was so impressed with it he has imported a few to Australia from the manufacturer for resale.

http://www.ebay.com.au/usr/mad_rc

Like the Turnigy, this is a single aileron channel stabilizer (but see Post 5 for discussion of use with dual ailerons or flaperons). On its own, it is a fairly useless stabilizer for my kind of flying – conventional fixed wing models. It works well but only has a restrictive auto leveling stabilization mode plus the GPS functionality. I assume it is of interest to FPV pilots, but when stabilization is on, it more or less just turns a plane into an unresponsive truck that you can steer around the sky.

Add it to the lemon DSMX/Rate stabilizer unit however and it is a completely different story. And it makes a much more compact, useful and lighter unit than the Turnigy T1000FC.

See Picture 3 which compares my new solution with my Turnigy T1000 equivalent.

What you need

All you need comes with the two stabilizers.
See Picture 4 showing what comes in the two packages.
You will also need either Ch6 (Aux1/Flaps on many Spektrum Tx) or Ch 7 (Aux2) free and controlled by a 3 position switch on your DSM2/X transmitter to manage the BGL-6G-AP.

The whole thing installs in a fairly small space. Here it is behind the battery compartment in my Multiplex EasyStarII test bed.
See Picture 5.
You can also remove the plastic protective GPS aerial case if space is really tight. Leaves a one inch square aerial unit. It seems to work just fine but I recommend clear (not black which may contain carbon) heatshrink to protect it and also note which way is up.

How it works


This “Autopilot” is a 6axis stabilizer that has three functions when the white GPS discus shaped aerial is connected.

1) OFF.
The one thing that the Turnigy T1000FC lacks - and which makes the T1000FC such a pain to use.
2) Auto-leveling.
The stabilizer will automatically level the plane in both pitch and roll when switched to this mode.
3) Automatic Return to Home using its GPS receiver.

I wanted this for use in motor gliders as an insurance policy. Normally I fly with the BGL-6G-AP turned off and use either no stabilization or, when in gusty conditions, the excellent Lemon built in stabilization by switching the Gear switch and adjusting the Gain knob as usual. If I do something stupid, get disoriented, or cannot tell which way the model is going, flicking the Flaps (Aux1) switch up will instantly level the plane out and keeping it flying straight and level. I can steer it around with the rudder or override the level with the ailerons and elevator if I need to. If I lose sight of it altogether, I just turn off the Lemon stabilizer, and flick the Flap switch down, put on about 50% throttle and the plane obediently turns around wherever it is and flies back to the launch point while maintaining the height it is at. The range of the Lemon receiver is far beyond any distance that I can see a plane.

Footnote 1: https://www.rcgroups.com/forums/show...&postcount=186
Last edited by jj604; May 31, 2015 at 07:23 PM. Reason: Added about needing a free channel and removing aerial housing.
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May 21, 2015, 07:33 AM
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Putting it together


The BGL-6G-AP can be integrated with the Lemon stabilizer with no additional parts, modifications or soldering in a couple of minutes. The servo leads that Bigaole supply are just fine but you can make the whole assembly a bit neater by replacing them with shorter ones if you want to. I did. Hobby King will sell you 10x “3cm Male to Male Servo Lead 26 SWG” Flight Controller leads for less than $5. Technically, some of us think they are properly described as Female to Female since the pins, not the housing, formally describe gender. Whatever they are called, they are just the right length for this sort of job.

http://www.hobbyking.com/hobbyking/s...dProduct=23036

You just need to swap one black lead pin into a spare empty servo connector housing.

See picture 1 which shows them compared.

Connect it up as shown. This shows the Single Aileron Servo Wing Type setup, which is very straightforward. The Single Aileron setup uses a Y lead with DIP6 Off and connects Aux1 as the BGL-6B control. It may be possible to set it up while retaining Dual Aileron servo or Flaperon functionality and this is covered in post 5 but the Single Aileron setup is simpler and provides more effective leveling and is recommended.

See Picture 2 which shows the connections for a singleaileron wing.

Then mount the BGL-6B on top of the Lemon stab with the tape supplied with the Lemon or BGL-6B. Everything on both stabs remains accessible EXCEPT the DIP switches on the Lemon so make sure you have set the Lemon gyro directions correctly before you join them up.

Connecting it up for Single Aileron Servo Wing Type

A Single Servo wing setup is simple and gives you the use of Channel 7 (Aux2) for something (like Flaps or Gear). It also works if you only have a DX6. However, as always, you do need an 8 channel transmitter to get in-flight gain control of the Lemon stabilizer.

Use a Y Lead and set the Lemon DIP6 to Off. Channel 5 (labeled ‘Gear’ on the receiver) controls the Lemon stabilizer function Off/On as usual, while Channel 6 (normally Aux1) controls the BGL-6B Auto level/Off/RTH. Channel 8, if you have it, is master gain for the Lemon stab as usual.

Picture 3 shows the wiring diagram for this single aileron wing setup.

This is by far the simplest to set up and has the advantage of providing a free channel for Flaps or Gear. Unless you REALLY need Aileron differential or Flaperons, I recommend it. It also makes the BGL-6G-AP much more assertive in auto leveling and the return-to-home turn radius. See the post 5 for a discussion about the possibilities of an alternative dual servo setup.

The end result

The next 3 pictures show what the assembled unit looks like.

If you are sharp eyed you may note that the BGL-6G-AP control wire is plugged into Aux2 not Aux1 on the Lemon receiver in these pictures. That’s because I am not using Flaps on this model and prefer to have the BGL-6G-AP control switch on the same side of my DX8 transmitter as the Lemon on/off and gain knob.
Last edited by jj604; May 22, 2015 at 05:43 AM.
May 21, 2015, 07:33 AM
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Setting it up


Step 1: Set up the control surface movements as usual with both stabs turned off.

Step 2: Set up the Lemon stabilizer with correct response direction and adjust the gains as usual. You may want to leave the BGL-6G-AP disconnected and connect the servos directly to the Lemon for the first flights till you are sure the Lemon stabilization is working correctly.

Step 3: Adjust the BGL-6G-AP to switch correctly using your 3 position switch. The BGL-6G-AP red LED flashes the same way in all modes to indicate the GPS is connected and so does not indicate what mode it is in - but it is easy to confirm.

1) With the BGL-6G-AP connected and Aux1 in the center (1) position, turn the Lemon stabilization off (both Red and Green LED On) with the gear switch.
2) Check the controls still work correctly. Then leave them at neutral.
3) Move the model in pitch and roll. Nothing should happen. This confirms the BGL-6G-AP is OFF.
4) Switch Aux 1 to the 0 position. Tilt the model in the pitch axis. The elevator should move and stay deflected until you level the model again. This confirms the BGL-6G-AP is in AUTO (self level) mode. Do the same in the roll axis the ailerons should operate similarly.
5) Switch Aux 1 to the 2 position. The ailerons will probably instantly deflect. Tilt the model in the pitch axis. Nothing should happen. Now hold the model level and rotate it about the vertical axis (like a totally flat turn). At some point the aileron(s) will move to neutral and then deflect the other way. This confirms the BGL-6G-AP is in RTH mode. See footnote about the rudder control.
6) Now is a good time to ensure that the gain controls on the BGL-6G-AP are set for correct deflection correction directions and adjust the BGL-6G-AP gain in flight.

Initialising the BGL-6G-AP and setting the gain and direction.

1) With the transmitter on and bound, and both the gear and Aux1 switch off, switch both BGL-6G-AP DIP switches on.
2) Connect power to the receiver/stabilizer
3) The Lemon will initialize as will the BGL-6G-AP. The BGL-6G-AP red LED will change from quick flash to solid red then a slightly slower flash. After a while the blue LED on the GPS aerial should start blinking slowly. The BGL-6G-AP is now talking to the GPS unit.
4) Power off and switch both BGL-6G-AP DIP switches off.
5) Set the model into level flight position, switch Aux1 to middle position, power up and wait till the red LED on the BGL-6G-AP DIP is flashing. Press the push button on the BGL-6G-AP DIP, wait for 3 seconds or so till the LED goes solid, and then release. Level is now set. Power off.
6) Switch Aux1 to RTH position, power up and wait till the red LED on the BGL-6G-AP DIP is flashing. Press the push button on the BGL-6G-AP DIP, wait for 3 seconds or so till the LED goes solid, and then release. The Home position is now set to where you currently are.

Both of these settings are retained by the BGL-6G-AP.

NEVER LEAVE THE GROUND WITHOUT CHECKING THAT:
1) The control surfaces move in the proper stick directions.
2) The Lemon stab corrects for disturbances in the correct direction.
3) The BGL-6G-AP levels the model with correct deflections

If you roll or pitch the model both stabs MUST give opposite correcting deflections if they are turned on. Roll to the right and the right aileron should go down, pitch the nose down and the elevator should go up. If you yaw the model, the Lemon stab should give opposite rudder.

This is true of any stabilizer installation - it is just with two in place you need to check even more carefully.

Footnote about the Rudder: Unlike the Lemon, the BGL-6G-AP does not (and does not need to) control the rudder at all. You have normal control over it with the stick. This means you can “steer” the model even when the BGL-6G-AP is maintaining auto level flight. It also means you can “steer” the model and override the RTH direction. When you let the rudder go it will obediently turn (using the ailerons) and head back home.
Last edited by jj604; Jun 07, 2015 at 06:16 PM. Reason: Corrected error in Step 3.1
May 21, 2015, 07:34 AM
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How well does it work


In a word – excellently.

When Aux1 is in the center, the Lemon stabilizer is completely unaffected and works as usual. You can switch it on and off using the Gear switch and adjust the gain in flight using the knob (if you have an 8 channel transmitter) perfectly normally.

When you flick the Aux1 switch to Auto, the model will immediately level out and maintain level flight no matter what its attitude. It does this almost as quickly as the Eagletree Guardian, which I regard as very fast. I found it did this even if the Lemon stabilizer was active, although it is faster when the Lemon is off. It holds a very stable level flight once the gyro gain is adjusted correctly.

The RTH also works very well. It is as good, if not better than, the Turnigy unit and significantly better than some others I have tried. If the Lemon stab were on you would turn it off, then switch Aux1 to RTH. Immediately the model turns round and heads straight back to you. As it passes overhead it goes into about a 50m diameter circle and will continue to circle, occasionally changing direction to set up a figure 8 pattern with the center based on where it was initialized. You need to maintain enough throttle to maintain height of course. But if you overdo it, the model maintains its altitude, just flies a bit faster.

A couple of special questions

Can I use it with Vtail and Elevons?

Should be able to - but there is a trick.
All fixed wing model stabilizers work on the 3 normal flight axes Roll, Pitch and Yaw. So all corrections are made assuming that. If the model uses angled or coupled surfaces to achieve control that mixing has to be done AFTER any stabilization corrections. So the Lemon stab has to be set up as though the model was a “normal” one and any Vtail and Elevon mixing done using the two DIP switches on the BGL-6G-AP. I have checked this works properly on the bench but have not set up a model with either VTail or Elevons. It may require some experimenting with connections and directions. Be interested if anyone gets it to work.

What happens if you turn on BOTH stabilizers?

That’s a very interesting question.
In theory you shouldn’t, as the reaction of the stabilizers will interfere with one another. In practice, the actual result is a function of stabilizer and model dynamics and theory doesn’t always turn out the way it should!

I found the Lemon/Turnigy1000FC combo would not work if you turned on both stabs. Very quickly the model would either dive off to one side or start galloping across the sky. With the Lemon/ BGL-6G-AP combo in the same plane it does seem to work fine. As you would expect the Lemon tries oppose the BGL-6G-AP corrections and reduce the speed with which it auto levels or heads for home but otherwise it seems to work. This will almost certainly depend on the model and its dynamics. I only checked it in a docile motor glider so test it for yourself.
Last edited by jj604; May 21, 2015 at 08:14 AM.
May 21, 2015, 07:35 AM
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Dual Servo/Flaperon Wing Type


If you use a Dual Servo wing setup and want to use Differential or Flaperons then set the Lemon DIP 6 on. Channel 5 (normally Gear) controls the Lemon stabilizer function Off/On while Channel 6 (normally Aux1) is the second aileron servo. Channel 7 (normally Aux2) now controls the BGL-6B Auto level/Off/RTH. Channel 8, if you have it, is master gain for the Lemon stab as usual. You should get full Lemon functionality but the BGL-6B will only control one aileron to level the plane in the roll axis. In theory this should work OK, but it isn't that simple to get working properly. The transmitter servo direction; Lemon stab response direction; which aileron the BGL-6G-AP controls; and the BGL-6G-AP response direction all interact.

Picture 1 shows how you would wire up a dual servo wing.

It ought to be simple and would look like picture 2 in practice.

The problem is that we now have a multitude of possibilities for connections since we have two aileron outputs and two servos, but only one BGL-6G-AP channel. It can be a challenge to get the aileron stick deflection AND the Lemon correction AND the BLG-6G correction all working properly.

The final picture shows the problem. There are 4 different ways to connect up the Lemon, BLG-6B and the two servos.

Add in: transmitter servo reversing, Lemon response direction reverse and BLG-6B response reverse and it could take quite a bit of mucking about to find a combination where everything works correctly. The problem is that the way the stabilizers reverse response direction also affects how the control surfaces move when the stab is off. It can be a real challenge to find a solution where everything moves the way it is supposed to. Even adding a servo reverser I was unable to find a combo that worked correctly. Be very interested if someone gets it working with full dual aileron servo functionality.
Last edited by jj604; May 21, 2015 at 08:22 AM.
May 21, 2015, 07:36 AM
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Reserved for updates


Post #71 has my "Compact" version. See attached picture.

Post #91 has a bit of a flight report.

Logic of setting it up.

Combining a receiver and two stabilisers can make setting it all up a bit confusing especially as the Bigaole seems to reverse servo directions.

So here's a step-by-step that ought to work every time for a single aileron servo setup.

Stage 1

1) Do not connect the Bigaole.
2) Set up your transmitter with a 2 position switch on channel 5 and a 3 position switch on channel 6. On Spektrum transmitters these are commonly the Gear switch and the Flap switch. If you do not have a 2 position switch, you can use a 3 position switch on channel 5 and just ignore the centre position.
3) Bind the Lemon to your Transmitter.
4) Plug a servo into channels 5 and 6.
5) Confirm that the channel 5 servo moves from one end to the other when you toggle the 2 position switch and that the red LED on the Lemon goes on and off.
6) Confirm that the channel 6 servo moves from one end to the centre then the other end when you move the 3 position switch. Which end is which doesn't matter at this stage.

If all that works, the Lemon is correctly set up (except for adjusting the gains and their direction). Do not connect the Bigaole till you get both switches working correctly. Now power off the receiver and remove the test servos.

Stage 2

1) Connect the Biagole stabiliser and the A,E,R servos as shown in the diagram in post #2. You do not bother about correct stick/surface direction at this stage.
2) With the Lemon stabiliser OFF using the 2 position switch, put the 3 position switch in the middle. Switch both white slide switches on the Biagole to ON. Power on and wait for both Lemon LEDs to come on and the Bigaole LED to start blinking.
3) Wait outdoors for a few minutes for the GPS to lock on to satellites, then push the small push button on the Bigaole. The blinking red LED will evetually go solid for a second or two then start blinking again. After a while the solid blue LED on the GPS will start blinking slowly.
4) The Biagaole is now working. Power off and slide both switches to off.

Stage 3

1) Get all the surfaces moving in the correct direction using servo reversing on your transmitter and both stabilisers turned off. You do not do this until BOTH stabilisers are connected up.
2) With the 3 position switch in the centre, turn on the Lemon stabilisation with the 2 position switch and adjust J1, J2, J3 to get the gyro reaction in the correct direction. Gain amount and Master gain (if used) is adjusted a usual. The Lemon should correct roll, pich and yaw.
3) With the 2 position switch off (both green and red LED on the Lemon), turn the 3 position switch to one end. Wave the model about. If the elevator moves that switch position is AUTO. If not it is RTH. Check a follows:
....a) With the Lemon off and Bigaole in Auto both aileron and elevator should move when you maove the model about.
....b) With the Lemon off and Bigaole in RTH only the aileron should move when you rotate the model about the vertical axis.
4) Set the correction directions and amount of stabilisation using the two pots on the Bigaole.
5) If you prefer the 3 position switch to have the RTH and Auto the other way round just reverse the channel 6 servo in your transmitter.

At any time you can set the level on the Bigaole by repeating the push button trick but with the two slide switches left off. They are only turned on for initialisation and setting up the GPS connection. The GPS will automatically set the home position wherever you are every time you power it up.
Last edited by jj604; Jun 07, 2015 at 07:57 AM.
May 21, 2015, 10:28 AM
Registered User
Great work and thank you very much for posting all this Informations!!
May 21, 2015, 11:44 AM
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weight?


thanks for the discovery of an amazing product.
i was looking at the pic but got mixed up. i was seeing the 2 as if were connected.
Last edited by phil alvirez; May 21, 2015 at 02:32 PM.
May 21, 2015, 01:30 PM
Registered User
This is very promising news. The GPS device is only $73.00.
http://www.rc-castle.com/index.php?r...aole+BGL-6G-AP
Couple it with the Lemon 7-Ch stab Rx for another $26.00 and you have a nice little package that rivals the T1000FC and less complicated, less inhibiting, more versatile.
My T1000FC and Buddy Box on my SkyMule does a similar thing but the rat's nest of wires is horrible.
May 21, 2015, 02:10 PM
Registered User

weight


i was asking for weight:
weight of bigaole shows 23 grams in the specs.
http://www.rc-castle.com/index.php?r...aole+BGL-6G-AP


- Dimensions: 23mm x 38mm
- Weight: 23g (with connecting cables & GPS)
- Operating voltage: DC 4.8V - 6V
- Operating current: 30ma
- Servo compatibility: 1.52ms analog servo, 1.52ms digital servo
- Radio compatibility:PPM, PCM & 2.4G
- Operating Temperature: -15℃ - 65℃

plus the lemon stab.

that could do with 2 mt sailplanes

and if i had this before i would not loose 2 planes.
Last edited by phil alvirez; May 21, 2015 at 02:34 PM.
May 21, 2015, 04:25 PM
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rudder-no ailerons


what if my plane has no ailerons? do i connect it to rudder instead?
what changes with it?
thanks
May 21, 2015, 06:45 PM
Registered User
Quote:
Originally Posted by phil alvirez
what if my plane has no ailerons? do i connect it to rudder instead?
what changes with it?
thanks
Planes like that (eg. Radian, Mystique RES), the rudder acts as the aileron and are generally plugged into the aileron channel. Rudder is empty.
May 21, 2015, 06:53 PM
Registered User

?


Quote:
Originally Posted by xviper
Planes like that (eg. Radian, Mystique RES), the rudder acts as the aileron and are generally plugged into the aileron channel. Rudder is empty.
thanks. i have been doing that with my aileronless planes, including when using the stabilizer and works fine.
my doubt is if it affects the behaviour of this device.
am talking about this at the end of post 3: Footnote about the Rudder: Unlike the Lemon, the BGL-6G-AP does not (and does not need to) control the rudder at all. You have normal control over it with the stick. This means you can “steer” the model even when the BGL-6G-AP is maintaining auto level flight. It also means you can “steer” the model and override the RTH direction. When you let the rudder go it will obediently turn (using the ailerons) and head back home.


John?
May 21, 2015, 07:05 PM
Registered User
Quote:
Originally Posted by phil alvirez
thanks. i have been doing that with my aileronless planes, including when using the stabilizer and works fine.
my doubt is if it affects the behaviour of this device.
am talking about this: Footnote about the Rudder: Unlike the Lemon, the BGL-6G-AP does not (and does not need to) control the rudder at all. You have normal control over it with the stick. This means you can “steer” the model even when the BGL-6G-AP is maintaining auto level flight. It also means you can “steer” the model and override the RTH direction. When you let the rudder go it will obediently turn (using the ailerons) and head back home.


John?
Planes that have high dihedral in the wings and have no ailerons, fly by rudder for roll (banking). Most stabilizers that incorporate a RTH function use "bank and yank" to steer the plane home. On my SkyMule, it only uses the ailerons and elevator to "bank and yank". The rudder is fed manually into the RX. Yes, I can still use it during RTH but why would I? Same goes for Alt/Heading hold. If you choose one of those functions, why would you interfere with the device trying to do its job? All that would happen is that if you introduced rudder input on a plane like that, the device would "bank and yank" harder to maintain heading.
If the plane has no ailerons, the actual rudder "becomes" the ailerons for that purpose and it goes into the aileron channel. With the rudder channel empty, you have no ability to input rudder and hence, no ability to interfere with the device trying to keep a heading. IE, on your aileron-less plane, nothing goes into the rudder channel anyway.

For stability, if the device detects roll, it would normally counter with aileron but since you have the rudder plugged into the aileron channel for aileron-less planes, it is still using "aileron" to counter the roll.
May 21, 2015, 10:27 PM
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Sorry, Phil your question arrived while I was asleep but I see xviper has answered - thanks.

Just to summarise the options.

We have 3 variables:

1) The transmitter. If you have a Tx that allows stick re-assignment like a DX9 then you can freely choose which Tx control stick (A or R) controls the Rudder. This is also true to more limited extent for a Tx like the DX8 if you have enough free mixes to do a "stick swap". That just changes which stick does what and does not affect the plane.
2) The Lemon stabiliser. This has three fixed channel assignments that are locked to the 3 flight axes and the Tx channels. That is, aileron is always on channel 2 and always responds to a movement about the roll axis. Similarly for the other two. So the Lemon does correct yaw using the rudder.
3) The Bigaole stabiliser. This has two independent channel assignments that are locked to only the pitch and roll flight axes but not the Tx channels. That is, the aileron output always responds to a movement about the roll axis. There is no third channel and the Bigaole does not respond to yaw changes in Auto mode. However in RTH mode it does respond to direction changes due to yaw and makes corrections using the ailerons. However the aileron input/output is not locked to a particular channel and can be used to pass on the rudder command to the rudder servo.

So what options does that give? Pitch is set up normally, but you do have a choice with roll and yaw.

1) One solution is to connect everything up as labelled. There are no connections to aileron on the Lemon or Bigaole. You get pitch and yaw correction from the Lemon when it is on, but pitch only correction in Auto mode on the Bigaole. This might be fine since Auto on a rudder/elevator model is probably being used just to bring the plane level in an emergency. However in RTH the Bigaole will not work since it is sending direction corrections to a non-existant aileron servo. This option doesn't make any sense for a rudder/elevator plane.

2) The obvious solution is to connect the Rudder (ch4) output of the Lemon to the Aileron input of the Bigaole and connect the Rudder servo to the Aileron output. You use the Rudder stick to turn.
When you have the Lemon stab on it will correct Yaw with Rudder. There is no Roll correction since there are no ailerons. The plane will roll due to dihedral when the rudder correction is applied by the Lemon and also self correct any induced roll.
When the Bigaole is switched on, it will self level in pitch correctly but will not level the wings. What it will do is deflect the rudder when it senses any roll. I suspect this will work fairly effectively, since it is what you would do manually to correct a bank on a rudder only plane, but it will depend on the model dynamics.
RTH should work, as it will maintain height normally but steer the model using the rudder rather than ailerons. All it does is keep the model turning until it is pointing straight at the home GPS position.

3) Alternatively you could connect the Aileron input of the Bigaole to the Aileron output of the Lemon and the Rudder servo to the Biagaole Aileron output. This changes the Lemon stab corrections. And you use Aileron stick to turn.
When the Lemon is on, if the plane rolls the rudder will deflect to correct the roll, if the plane yaws there will be no active correction - just the normal aerodynamic one.
With the Bigaole on, in Auto it will attempt to level the plane in pitch using the elevator and in roll using the rudder. In RTH the Bigaole will keep height as usual and adjust direction using the rudder.

Might be worth trying both 2 and 3 and see which works best for you.

With a basic transmitter with fixed channels, which option you chose also forces which stick controls the rudder: Aileron or Rudder. With a more capable transmitter that has channel re-assignment or sufficient mixes this is not a factor.

John



Quote:
Originally Posted by phil alvirez
thanks. i have been doing that with my aileronless planes, including when using the stabilizer and works fine.
my doubt is if it affects the behaviour of this device.
am talking about this at the end of post 3: Footnote about the Rudder: Unlike the Lemon, the BGL-6G-AP does not (and does not need to) control the rudder at all. You have normal control over it with the stick. This means you can “steer” the model even when the BGL-6G-AP is maintaining auto level flight. It also means you can “steer” the model and override the RTH direction. When you let the rudder go it will obediently turn (using the ailerons) and head back home.


John?
Quote:
Originally Posted by xviper
Planes that have high dihedral in the wings and have no ailerons, fly by rudder for roll (banking). Most stabilizers that incorporate a RTH function use "bank and yank" to steer the plane home. On my SkyMule, it only uses the ailerons and elevator to "bank and yank". The rudder is fed manually into the RX. Yes, I can still use it during RTH but why would I? Same goes for Alt/Heading hold. If you choose one of those functions, why would you interfere with the device trying to do its job? All that would happen is that if you introduced rudder input on a plane like that, the device would "bank and yank" harder to maintain heading.
If the plane has no ailerons, the actual rudder "becomes" the ailerons for that purpose and it goes into the aileron channel. With the rudder channel empty, you have no ability to input rudder and hence, no ability to interfere with the device trying to keep a heading. IE, on your aileron-less plane, nothing goes into the rudder channel anyway.

For stability, if the device detects roll, it would normally counter with aileron but since you have the rudder plugged into the aileron channel for aileron-less planes, it is still using "aileron" to counter the roll.


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