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Old May 11, 2014, 09:13 AM
ancora imparo
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The official Lemon stabilizer receiver thread

This thread is an attempt to bring together information on the Lemon 6 channel stabilizer (and any later models). It is not an alternative to the main discussion about Lemon products but an attempt to make specific information on the stabilizer easy to find. I will update the first few posts regularly when new information or useful tips are posted.

Frederick, the Lemon CEO has indicated that he is happy for this to be the official Lemon stabiliser thread and that he will monitor it in addition to the main Lemon receiver thread.

For about $16 the Lemon is a very attractive lightweight full range 3 axis receiver stabilizer combo. However information about it is scattered throughout the main Lemon receiver thread and is getting hard to find. I have copied some bits from that thread but haven’t generally given the original reference so thanks to everyone who contributed.

Background

Lemon receivers are low cost, but high performance, DSM2/DSMX receivers directly competing with the well known Orange range from HobbyKing and the various copies of the Spektrum units. Ironically they were originally called Orange receivers but had to change the name because of the HobbyKing brand.

http://www.lemon-rx.com/shop/index.p...te=common/home

They started out with a DSM2 only version of a very compact and light 6 channel receiver and it turned out to be better made than the competition, have longer range, be extremely reliable and cheap as chips. They now make several 6 channel versions together with 8 and 10 channel receivers some with PPM and UART out and also DMX versions. Over a substantial period, despite the obvious jokes about the name from the Americans , they have gained respect as an extremely well designed and well-supported product from a small responsive apparantly Taiwanese manufacturer (although all the stuff comes from Fo Tan in Hong Kong). The Lemon receivers are designed by a BCIT grad... a fact the Lemon CEO Frederick who lives in Vancouver (fmak2 on the forums) is quite proud of.

The main Lemon thread is here

http://www.rcgroups.com/forums/showt...tabilis&page=1

Version 1

A stabilizer version of the receiver was announced as placed in production and the design prototype was pictured on the Lemon thread on 24 July 2013. It was eventually made available on Aug 10th.

The first posted flight report from a user on Aug24th was of a disaster. That same day Lemon responded to the modeler with an analysis of the issue, and announced on the Lemon thread that the stabilizer was susceptible to voltage drop under certain conditions with an inadequate BEC. Mine worked well in rate mode with a known solid BEC but was not useful in AVCS (“heading hold”) mode, which IMO is of limited utility on a low cost stabilizer without very high quality hardware and software (like the ICE Man Pro) or accelerometers (like the Guardian). AVCS was removed in the next version.

Lemon set about redesigning the unit, and immediately reimbursed those who had purchased them together with a discount offer on standard receivers as a compensation. Generally Lemon has been very highly regarded on the forum for their responsiveness to customers and customer suggestions and the way in which they deal with faulty units.

Version 2

The revised design was finally made available on Feb 5, 2014. It was quite different from the original in board layout and was in fact a DSMX receiver (although a few early purchasers received a DSM2 version which was available for a couple of days).

Lemon explained the change to DSMX virtually on the day they had released the DSM2 version, “It's just that DSMX will also work on DSM2 transmitter. For this reason, we have removed the DSM2 stabilizer from our website for sales even though it was already developed and fully tested.”

I have called this version of the DSMX 7 channel stabilizer Version2.

See the attached picture of Version 1 and Version 2 compared with the Orange 4 channel and 6 channel DSM2 stabilisers.

The version 2 stabilizer weighs just under 5 grams, and can also take an additional satellite receiver for a total of about 8g. This is similar to the Orange 4 channel DSM2 stabilizer but significantly smaller and lighter than the Orange 6 channel stabilizer (although of course that comes in a case).

Version 3

There is a revised version 3 based on user suggestions almost ready for release at the time of writing that will come in a case and has significant operational improvements and I will put what is known about it in separate posts. There have been requests for an alternate endpin version like the original for tight fitting applications but it remains to be seen if having a hard case will make that unlikely. I also think a pin-less and case-less ultra light version would be popular with the micro crowd but we will have to see what eventuates.

UPDATE Version3 was released on May 12th. The website instructions are still partly for V2. The control channel has moved to Gear and two aileron outputs are available.
Version 4 started shipping at the end of August. It is identical to V3 but has Aux2 available while in stabilised mode.


I have put instructions on how to use it in this thread at Post #3.

http://www.rcgroups.com/forums/showt...6#post29478793
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Old May 11, 2014, 09:14 AM
ancora imparo
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Melbourne, Australia
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About Version 2

NOTE THAT THIS DISCUSSION IS ABOUT V2. ALL LEMON STABILISERS NOW SUPPLIED ARE V3 V4.

YOU CAN TELL IT IS V3 or V4 IF IT COMES IN A PLASTIC CASE. THE SIGNIFICANT CHANGE IS THAT ALL REFERENCES TO CONTROLLING THE STABILISER BY THE AUX1 CHANNEL SHOULD NOW MEAN THE GEAR CHANNEL


How many channels actually is the stabilized receiver?

This has caused some confusion, partly because it was originally advertised as a 7-channel receiver and is now shown a 6-channel receiver.

Why the confusion?

The technical answer is that it is actually a 10-channel DSMX receiver but only the first 8 channels are used.

The practical answer is - it depends.

The stabilizer “could” be regarded as a 5 channel, 6 channel 7 channel or 8 channel receiver depending what transmitter you use and how you have it configured.

In practice it only has 5 available independent flight controls available out of the receiver to connect to servos.

They are the first 5 standard Spektrum channels. Throttle, Aileron, Elevator, Rudder, Gear.

The complications.

Channel 6

1) Aux1 out is also available as a servo connector on the receiver but since this transmitter channel is used to switch the stabilizer on and off in flight it has very limited application. You can only use it to drive something that will always follow the stab on/off command. Because Aux 1 is a three-position switch it is possible by adjusting the travel to separate the two functions in a partial way but it has limited use. For example you could have:

Posn. 0= Stab OFF Other function OFF
Posn. 1= Stab ON Other function OFF
Posn. 2= Stab ON Other function ON


2) Since Aux1 is hard wired as an on/off switch internally in the receiver, you cannot use the Spektrum independent dual aileron function. In particular you can only use the Normal Wing Type in your transmitter setup. If you choose Dual Aileron wing Spektrum sets Aux1 to be LAL (Left Aileron) and the stabilizer will be switched on and off every time you roll. Many cheap stabilizers, even if they have two aileron outputs pins, can only accept one aileron control input. This is a significant limitation for those wanting aileron differential, flaperons and the like and is fixed in version3.

UPDATE: Version 3 has fixed this problem. See Post #5.

Channel 7

1) Aux2 is not available at all as an output when the stabilizer is active on V3 but is on V4.

2) However it is possible to disable the stabilizer completely using the on-board DIP switch and it then becomes a conventional non-stabilized 7 channel receiver. Aux1 operates as a normal output and Aux2 is now available on the Bind connection. This is why Lemon originally advertised it as a 7-channel receiver.

3) BUT early production of the stabilizer had a problem. Some servos have a low enough resistance when connected to these pins that they work like a Bind plug. So in order to have 7 channels with these servos (many common analog servos which will be popular with this receiver fall into this category) you needed to connect the 7th servo after the receiver is powered. Current production has had this problem fixed, but if you wanted a 7 channel non-stabilized receiver their 8 channel normal receiver is lighter, simpler and cheaper.

Channel 8

1) If you have a DX8 or better, then the Aux3 channel works to control the Master Gain of the stabilizer. A DX7 has a knob but it is not on channel 8 and a DX7 cannot control Master Gain.

2) This is not a receiver option. It is always there, but a 7-channel or less transmitter simply does not send the signal and the Master Gain defaults automatically to a value of 1.

There is a summary of how the various channels work attached to Post #5.
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Old May 11, 2014, 09:15 AM
ancora imparo
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Orientation

The Lemon does not have a computer interface like more sophisticated stabilizers such as the Eagletree Guardian and because it is an integrated receiver/stabilizer you cannot change the stabilization axes within the stabilizer. This has implications for how you can mount it – and the flexibility you have depends on the sophistication of your transmitter.

On stand-alone stabilizers there is nothing to stop you manually swapping the channels. They are just 3 orthogonal gyros with their own gains. The labels are a convention. As long as you swap BOTH the inputs and outputs you can swap over two directions.

But you cannot do that with an integrated receiver/stabilizer like the Lemon as the channels are internally fixed. This may be a problem if you want to mount it in any other way than that recommended.

See the diagram of the plane for identification of the 3 names of the control axes. The normal way to mount the stabiliser is horizontally facing fore and aft and with the pins toward the rear.

You can rotate the Lemon through 180 degrees on any axis and still have it work by changing the 3 directional DIP switches.

However you cannot rotate it by 90 degrees on any axis without changing the order of the control channels.

So you can mount it upside down without any problem but you cannot mount it vertically on the side of a profile foamy unless your transmitter allows channel order to be changed. The DX8 does not allow channel reassignment for example but the DX9 does.

However it is possible to effectively change channel order by a combination of mixes on a transmitter that has enough of them. So although a DX8 does not allow channel reallocation it is possible to swap two channels by cross mixing them to one another. The most common situation of mounting the Lemon on the side of a profile fuselage requires 2 axes to be changed (Yaw and Pitch) which requires 4 mixes. My DX8 with the latest firmware has 6 free mixes which is more than enough. It is only a workaround however as the trims stay on the original channels.

Poster JMP_Blackfoot did a nice summary on the Lemon receiver thread that shows all the options for orientation.

To elaborate on the subject of orientation, if you have a transmitter that allows for free channel allocation, then it does not matter how the stabilizer-receiver is mounted (in a fixed wing model).
The 3 axes are interchangeable; just change the channel allocation to suit (Standard is Ail= ch2, El=ch3, Rud=ch4)

Here are the channel allocations for the 6 possible positions as shown in the drawing:
1 - Lengthwise on floor : Ail=ch2, El=ch3, Rud=ch4 (this is the standard)
2 - Crosswise on floor : Ail=ch3, El=ch2, Rud=ch4
3 - Lengthwise on side : Ail=ch2, El=ch4, Rud=ch3
4 - Vertical on side : Ail=ch3, El=ch4, Rud=ch2
5 - Vertical on bulkhead : Ail=ch4, El=ch3, Rud=ch2
6 - Crosswise on bulkhead : Ail=ch4, El=ch2, Rud=ch3


I have attached his diagram showing all 6 options.
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Old May 11, 2014, 09:16 AM
ancora imparo
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Common questions/observations

Flight test observations

Most people seem to find the stabilizer works extremely well in flight. In that respect it does what any simple 3-axis gyro only stabilizer does – damps out external disturbances. It makes flying in windy conditions much easier. General reports are that the pot range and settings and inflight master gain control make this a superior product in the simple stabilizer category.

Mechanical issues

The version2 came without any case. This is not a big deal for a cheap receiver but it IS for a stabilizer, which needs to be securely mounted.

a) The PC board is good quality but thin and in danger of damage when you need to peel it off whatever you mounted it on. The double-sided tape they supply is hard to separate. Because the receiver is a two-board assembly it is highly susceptible to the daughter board detaching when you try and separate the double-sided tape.

“Guys,
Just a word of warning. I received a DSMX stabilized receiver and upon initial binding, the receiver board detached from the stabilizer board. I was handling it with a lot of care.

Upon closer inspection, there's a small amount of hot glue near the antenna and in my case, it wasn't stuck to the stabilizer board. The only thing holding the two boards together are 3 small solder joints on one edge of the board.”


One recommendation is to put some thin heat shrink around the PC boards which will hold them tightly together.

b) The aerials are a weak point and a potential failure risk. They are heavy wire soldered direct to the board and with no strain relief except a small dab of goop of some kind. Better than nothing but not much. Lemon have progressively improved this during production however with thinner wire and additional strain relief.

Lemon say they have addressed all these issues with the new version 3 which comes with a case.

UPDATE: Indeed they did. See updated post #5. V3 is significantly improved and is now a very neat unit mechanically as well as electrically.

Failsafe

As far as I know it provides only standard Spektrum-type "Smart Failsafe" - that is preset failsafe on CH1 only for throttle and hold on the other channels.
UPDATE: Lemon stabilisers do not have active failsafe. They output no signal to the servos on radio link lost. In practice what this means is that any modern ESC will shut down after 2-3 seconds and control surface servos will stay where they were when the signal was lost.

Setting the gains

It will work just the same as any other 3-axis stabilizer with remote gain.

You adjust the individual gains for each of the 3 axes with master gain set to 1 (mid position on the Aux 3 pot).

When you are happy that you have each flight axis right, you can wind the overall gain up or down in flight to suit the conditions or flight envelop. For example if you are flying faster than usual and you get some oscillation starting just back off the master gain.

Think of it as an overall volume control you can use in flight. The 3 on board pots are the volumes of individual channels pre-set on the ground.


For transmitters below a DX8 there is no Master Gain control and the stabilizer defaults automatically to a gain of 1.

11mS vs 22mS issue.

The servo outputs on Spektrum receivers can refresh at either11Ms or 22mS intervals. 22mS is the normal standard and works with all servos. 11mS gives faster refresh but is only for digital servos. There is considerable confusion about this topic as there are two places where the 11/22mS applies – between transmitter and receiver and also between receiver and servo. Spektrum gear manages it automatically but some users were reporting being unable to force the Lemon to use 22mS with analog servos. Lemon have now changed the stab so that it only outputs at 22mS. This IMO is appropriate for a simple stabilizer. It applies to stabs sold after March 14, 2014.

In practice it was a problem for the DX6i, which you had to set in DSM2 before binding or it wouldn’t work properly. With other radios it was fine in both DSM2 and DSMX mode.

There is an excellent detailed explanation of the issue in this post by Ben http://www.rcgroups.com/forums/showp...postcount=3726
but it is more than most people will need to know.

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Old May 11, 2014, 09:17 AM
ancora imparo
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Version 3

Some suggestions were made for improving the Lemon Stabilizer. Here is what they said that version three would have:

We have actually done / doing the following at the moment.
1) Changed it as "6-channel stabilizer" on website. We will not mention about the 7-channel on user manual at all. We haven't change the firmware at all so channel #7 (aux2) will become a hidden trick for those who urgently needs an extra channel for whatever reason.

2) Plastic casing is still being fabricated but once it is completed, the stabilizer is much more robust to handling and installation issue.

3) - Gyro on off to channel 5 (Gear channel).
- DIPswitch 4 and 5 will become (Fixed Wing single servo Aileron, V-tail, Delta, Fixed Wing dual servo aileron. For fixed wing dual servo aileron user can select dual aileron on Spektrum transmitter)
- For dual aileron settings gear channel will be used for the 2nd servo.
- J6 on is for disabling the Gyro
- A label that says "see webpage for step by step instructions"
- 22ms output permanently so it fits all servos


Version3 was released on May 12th. Due to production delays caused by Lemon establishing a new factory only a few were shipped and the main shipping date was May 26th.

The final version 3 varies from what was said above in that J6 was not used to disable the gyro, which is now achieved by turning DIP switches 4 and 5 off.

The significant thing to note is the change from Aux1 to Gear to switch the stabilizer off and on which has allowed two aileron servos to be used - the Dual Aileron and Flaperon modes in the Spektrum "Wing Type" menu. This is a big plus as the Lemon stabiliser can now provide full dual aileron servo capability including differential and flaperons.

Note that although you can put a servo on the gear output it would normally not be used in stabiliser mode- unless you want you gear to go up and down when the stabiliser is turned on and off. If you have retracts they will need go on the Aux1 output and then you cannot use the Dual aileron/Flaperon setting on the transmitter.

The Aux2 output (on the bind plug) only functions in stabilizer- disabled mode as before. Lemon have said they will look into changing this in the future. Would be very useful for DX7 and above owners who could then have full dual aileron as well as gear or separate flaps.

UPDATE: This was the improvement made in v4.

Aux3 controls master gain as before for DX8 and above transmitters.

The stabiliser is now usable (for a single aileron setup) with a DX4 or 5 since they both transmit a switchable 5th channel.

The v3 stabilizer comes in a case, as does its satellite. It is therefore much more robust and easier to mount than v2 and one very big improvement is that the aerials are now well secured by plastic mouldings on the case. The whole thing, including the label, is very neat and well thought out. Lemon have done an excellent job of the mechanical design as well as the electronics.

My stabilizer weighs exactly 8.002 g cased; the satellite is 2.542g and the connecting cable 1.782g. So total weight for a satellite version is just over 12 g (well under ½ oz).

If you remove the case from the receiver/stab, don’t use the satellite, and are careful of the aerial and mounting you end up with a DSMX full range receiver stabilizer weighing exactly 4.5g – pretty neat.

To remove the case there are two small screws, then the other end has to be pried apart with a thin knife at the join as there are two plastic studs that are a push fit in holes in the case. Don't bend the case apart or you will break the little plastic studs.

I have attached a pdf cheat sheet that summarises all the options of the 3 DIP switches 4, 5, 6 and the result you get for all Spektrum transmitters. It is based on testing with my DX8 and LP5DSM but I am fairly sure the others are correct. Would appreciate it if anyone spots an error they would let me know.

I have also included it as 3 screen shots as that makes it a bit more obvious.

UPDATE: The latest version of the Instructions and DIP switch options is on the dedicated Lemon Instructions thread.

http://www.rcgroups.com/forums/showthread.php?t=2249026

John
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Old May 11, 2014, 09:17 AM
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Later versions

Version 4 of the "simple stabiliser".

Lemon have updated the firmware of Version 3 to enable Aux2 to be output when the stabiliser was engaged - not just when it was used as a normal receiver.

I tested a pre-production sample on 17 Aug and it seems to work perfectly. See Post #908. We await an official announcement from Lemon as to when it will be in production. Version 4 looks identical to Version 3 but this modification allows Flaps and Gear on a single aileron servo wing type or Flaps or Gear if using dual aileron or flaperon servo wing. It is likely that the new version will be distinguishable by a double flash of the two LEDs when powered up but that remains to be confirmed.

In my view this is likely to be the final version of the simple stabiliser.

UPDATE: The v4 stabiliser started shipping without any announcement at the end of August 2014. You can check if you have a v4 by the two quick flashes of both LEDs when you power up.
At least one user has reported a V4 that has Aux2 enabled but no double flashes. It may be part of a small batch of the first production of v4.

The super stabiliser

Lemon have announced they are developing a "super stabiliser" that will incorporate GPS and accelerometers all in the one package - hopefully the same size as the Lemon 10channel receiver. If they can do this, it will be a remarkable achievement and a very useful device. A DSMX receiver of Lemon range and robustness that incorporated sophisticated stabilisation, 8 free channels and a Return to Home capacity would be a real winner IMO. It is some time off yet though.
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Old May 11, 2014, 09:18 AM
ancora imparo
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Hints and Tips

NOTE: This post is now updated to reflect the changes to v3 and v4 of the stabiliser.

Stick centering
Some people seem to overlook the need for initial calibration of the stabilizer to their transmitter.

From the instructions, “Upon trimming, toggle Gear switch twice in 1 second allows stick centering detection which is required for optimizing the stabilization.” The LED will flash rapidly.

See Post #272 for an explanation of why this may be important.

The GEAR control is not correctly set
A number of mysterious in flight “problems” have turned out to be caused by the stabilizer simply not being switched on. It’s easy to check by plugging a spare servo into the GEAR pins and seeing if it moves from one end to the other when the switch is toggled.

Green + red means no gyro while solid green means gyro is enabled.

Setting the Pots
Here is one users experience.

I have tried in several planes, and believe 10 o’clock is a good start.

What I find is it depends a lot on how the plane is set up. The receiver/stabilizer is working independent of the transmitter, so for example the amount of stabilization movement is the same whether you fly on high or low rates. I'm lazy so have some planes with the end points adjusted from the transmitter, some as low as 75% at full setting. The stab doesn't know this and will still move the surfaces as if 100% used.


From Daedalus66

My experience too was that aileron needed a little less gain than elevator or rudder.

If you have the master gain control hooked up on channel 8, make sure it's in the middle or a little below for takeoff. In the air, increase master gain progressively till you get oscillation, then back off a little. Note which axis experiences the oscillation. After you land, reduce the individual gain setting for the corresponding channel. When you get all three channels balanced, you can use master gain to tune stabilization to the type of flying you want to do. Remember that oscillation is dependent on speed.

Voltage
The Lemon stab is specified to work from 3.45 -7.2V .

In practice you can run it off a single LiPo cell, normal 4.8 or 5V supply or two LiFe's.
These ratings are probably very conservative. Many people have used the featherlight Lemon 6ch receiver off a 1S LipO and it keeps operating well below the specified 3.45V. I am pretty sure the stab would happily run off a 2S Lipo as well but haven't tested it.

UPDATE: I have now tested the stab and it operates correctly down to 3.3V. Lemon have advised that the circuitry is designed to operate on 3V but that there is a 0.3 V drop from the voltage regulator. Their specified 3.45V min is a sensible number to allow some variation in stabilisers, but the bottom line is that this stabiliser will work reliably on a 1S LiPo.

Around post 316 there is examples of how to change the pins to 1.25mm Molex connectors in order to use the very popular HobbyKing 1.7g servos. A stabiliser with 4 servos weighs less than 11g.

Watch your BEC

From Rich in ILM

Just wanted to pass along something that came up in another discussion. If you have the stabilizer on for a lot of the flight, the average current draw can go up quite a bit in windy conditions. My first stabilizer (early HK) went into a PNP plane with a liner bec in the ESC. The BEC wasn't up to it and I was lucky the plane was just landing when I lost everything. Anyway I would suggest making sure you have a switching BEC in your ESC or use a stand alone BEC. In general linear BEC's suck for all but the lightest 3s and 4s applications.

Using an Orange transmitter

mgdon has posted detailed instructions on how he set up his Orange transmitter to gives flaperons, exponential and aileron differential using 2 separate
Aileron servos here.

http://www.rcgroups.com/forums/showp...&postcount=970
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Old May 11, 2014, 09:19 AM
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Updates and new information

Oranges and Lemons

The obvious competitor in the price range for the Lemon is the Orange ORX v3 integrated DSM2 Rx/Flight stabiliser from HobbyKing. There is discussion later in the thread about the advantages of the Lemon DSMX v3. Just for info, the first picture shows the two side by side showing their size and weight.

The action of Master Gain

Daedalus and Frederick (fmak, the Lemon man) have clarified the action of Master gain and its dependence on the way in which different transmitters treat servo travel. Most people will be using a Spektrum transmitter but folks with DSMX/2 modules or hacks in other transmitters will see some variation.

In Spektrum terms -/+ 150% is the gain multiplication factor from x0.0 to x2.0 on the Aux3 channel - with unity gain (no modification to the onboard pots) at centre position which is 0%. 150% is the maximum range the Spektrum will put out if you extend the servo travel limits. However most people will probably be using the default -/+ 100%. The stabilizer master gain will then be adjusted from around 0.3 to 1.7 by the knob (Aux3). In other words turning the knob fully clockwise does not completely turn off stabilisation.

If you have another make of transmitter it can get a bit complicated since not all manufacturers use % the same way.

From Daedalus66

For anyone using a 9x transmitter with ER9x firmware, a Taranis, or a 9XR, note that all the open source firmwares are set up from Spektrum/JR. On these transmitters,100% is equivalent to 125% on Spektrum/JR.

Everything is much clearer if we look at the actual pulse width.

For Spektrum/JR, +/-100% corresponds to a pulse width range of 1.1 to 1.9 ms. For open source firmware, +/-100% is 1.0 to 2.0ms.

The Spektrum 150% being referred to here is therefore 0.9 to 2.1ms. To get this with open source firmware you have to enable extended limits (method varies with type of firmware) and set to 120%.

Confusing at first, but it explains why models set up for mainstream transmitters respond differently when used with say a 9XR with apparently similar settings.

His later post is a nice summary:

"To achieve full in flight control over master gain, from zero to a multiplier of 2, set the travel (end points) of channel 8 (Aux3) to give a pulse width range of 0.9 to 2.1 ms. For Spektrum and many other transmitters, this corresponds to +/-150% travel. For transmitters such as Taranis and 9XR using open source firmware, the same pulse range is achieved at +/-120%.

If a reduced travel is used, such as 100% on a Spektrum transmitter, this will still give a range of gain control which is ample for normal purposes.

If channel 8 is not available on the transmitter, the receiver will automatically use a master gain factor of 1. Gain of individual channels can still be controlled using the pots in the receiver."


Channel limitations

No matter what transmitter you have, the Lemon stabiliser can only output 5 independent flight control channels. Normally these will be T,A,E,R and Aux1 or T,RAR,E,R and LAR. You can put Gear OR Flaps on Aux1 only if you use a single servo wing setup on your transmitter. No clever mixing will be able to give you independent Gear and Flaps until Lemon update the stabiliser to provide Aux2 on the Bind pins. While Gear out is available it is essentially useless since it follows the on/off switching of the stabiliser.
UPDATE: V4 fixes this problem. Aux2 now works.

For fun I made a 9channel version of the stabiliser using a Lemon 10ch receiver and a different manufacturers 3 axis stabiliser. It works really well but it isn't a practical solution for most people. Post 602 has my DIY 9channel Receiver/Stabiliser using a Lemon DSMX receiver and NX3 3 axis stabiliser.

I also made up a combined Rx /stabiliser from a 10ch Lemon Receiver and an Eagletree Guardian. This works extremelly well and makes a neat sophisticated stabiliser with Lemon's exceptional DSMX performance. It has 8 available flight control channels: Throttle, Aileron, Elevator, Rudder, RAL/Aux1, Aux2, Aux4, Aux5

Effect of the stabiliser on aircraft response to the sticks

Any simple rate stabiliser will add some "mushiness" to stick response. The reason is inherent in the way stabilisation works. As soon as you initiate a deviation by moving the stick, the stabiliser senses it and tries to oppose it. However the programming of the stabiliser has a big effect on how much of an issue this is. By reducing the amount of stabilisation as the input deviation is increased it can be minimised. The Lemon is fairly good in this regard compared with some other cheap stabilisers.

From victapilot

"Gyro effect diminishes linearly to zero at full stick, assuming full stick equals max range. I would prefer zero gyro at 75% stick, but that's not the way it works.
If full stick is anything less than max range, then there will always be some gyro effect."

Rich in ILM noted:

"It is interesting that, somewhere, in the instructions for the stabilizer it says to turn off all mixes. Again my roll rate is the same with full stick gyro on or off and that is on a couple of planes. I don't think the gyro is intrusive after about 40% stick if you are running clean."
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Old May 11, 2014, 11:50 AM
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Great start - thanks.

I've got one of the initial versions, and will be ordering up a few more once the dual aileron support is available. The lone v1 version I have is installed in a hot-rodded T-28, and after a bit of trial and error I'm pretty happy with it. The main problem I had was trying to get adequate stabilization over a wide range of speed. With the wide flight envelope I have with my T28, there's definitely a need to routinely adjust master gain in flight depending on how I'm flying.

It takes more time, but here's how I dialed it in.

- Adjust the control surface gain pots one at a time. This might sound like overkill, but with all three surfaces being stabilized I have trouble telling where the jitter is coming from in the air. With only one surface actively stabilized, there's no doubt. Zero out the two not being adjusted, and set master gain to about 50%.

- Fly it, adjusting the pot until there's no jitter on the one surface being stabilized at low speeds. At higher speeds, ensure you can eliminate the jitter on the surface by reducing the master gain.

- Repeat the above for the other two stabilized channels.

Once done, adjusting master gain provides great stabilization at any speed without jitter. And, for those of you with DX9's - try using the slider switches on the back for master gain. Much easier to adjust than the knob on top; you don't need to take your hands off the sticks, and you can tell by feel exactly where you have the gain set currently.
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Old May 11, 2014, 11:54 AM
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San Jose, Ca.
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Off topic:

You Rock, JJ !!!!

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Old May 11, 2014, 12:29 PM
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San Jose, Ca.
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Quote:
Originally Posted by syspig View Post
Great start - thanks.

I've got one of the initial versions, and will be ordering up a few more once the dual aileron support is available. The lone v1 version I have is installed in a hot-rodded T-28, and after a bit of trial and error I'm pretty happy with it. The main problem I had was trying to get adequate stabilization over a wide range of speed. With the wide flight envelope I have with my T28, there's definitely a need to routinely adjust master gain in flight depending on how I'm flying.

It takes more time, but here's how I dialed it in.

- Adjust the control surface gain pots one at a time. This might sound like overkill, but with all three surfaces being stabilized I have trouble telling where the jitter is coming from in the air. With only one surface actively stabilized, there's no doubt. Zero out the two not being adjusted, and set master gain to about 50%.

- Fly it, adjusting the pot until there's no jitter on the one surface being stabilized at low speeds. At higher speeds, ensure you can eliminate the jitter on the surface by reducing the master gain.

- Repeat the above for the other two stabilized channels.

Once done, adjusting master gain provides great stabilization at any speed without jitter. And, for those of you with DX9's - try using the slider switches on the back for master gain. Much easier to adjust than the knob on top; you don't need to take your hands off the sticks, and you can tell by feel exactly where you have the gain set currently.
You're making me want to get a 9 instead of the new 6!

bob
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Old May 11, 2014, 01:00 PM
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United Kingdom, Yeadon
Joined Mar 2007
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Can't wait for the V3

I have a V2 but not used it yet. I'm wanting full dual aileron support for flapperons etc.


Tony
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Old May 11, 2014, 03:15 PM
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United Kingdom, Yeadon
Joined Mar 2007
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I've just noticed that my DSMX stabilizer looks to have come with a DSM2 satellite...

Not good!
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Old May 11, 2014, 03:35 PM
Scout CX | mCX2 | mSR | 120SR
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Canada, AB, Edmonton
Joined Dec 2011
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Are you saying that because of something printed on the board? I seem to remember something about the new ones using the older dsm2 boards. Don't quote me on that, but something like that rings a bell.
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Old May 11, 2014, 03:53 PM
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United Kingdom, Yeadon
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Yes.

I've checked the website, it looks like the DSM2 satellite has one antenna and the DSMX one has 2 antennas. It might just be marked up wrong...
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