S8R and Delta Wing

[Mik120]

Hi. Got a new ‘stupid’ question
I’m setting up an old twinjet model with a S8R reciever, but since the delta wing mixing is done by the reciever, I just can’t get the throws right?
I have my aileron and elevator setup on channel 1&2 and they do work, but I need to invert the throw on ch2.
(Or take out the servo and flip it)
I know, it’s probably a stupid question, but can that really not be done on the TX or with openTX?
Everything I try seems to confuse the RX in its mixing…

 

[gnichola]

I think you can just go to the outputs and change the direction.

 

[Mik120]

I tried that, and it does change the output, but no matter what I try, I can’t get the right direction on the servos.
They are mounted ‘mirrored’ (if that makes any sense).
But when I pull back, for instance, one goes up and one goes down. If I change direction of one servo, the ‘one’ goes down instead and the second one goes up
The ‘wing’-mix is done in the reciever, and I think that’s why it gets confused

 

[gnichola]

Oh, I haven't setup the gyro rx with a delta, but this isn't like a "controller". For example, on my helicopters I use a 3 axis gyro and all the mixing is done there. The gyro here is not that. My suggestion is to turn off the gyro feature of the receiver and get the mixing right first, then turn on the gyro and set it up.
If you disable the gyro, the radio setup should be simple. Elevator should move both surfaces in the same direction, and if not, reverse one output. Then it should be a simple matter of setting the correct direction for ail/ele

 

[Mik120]

Oh, I haven't setup the gyro rx with a delta, but this isn't like a "controller". For example, on my helicopters I use a 3 axis gyro and all the mixing is done there. The gyro here is not that. My suggestion is to turn off the gyro feature of the receiver and get the mixing right first, then turn on the gyro and set it up.
If you disable the gyro, the radio setup should be simple. Elevator should move both surfaces in the same direction, and if not, reverse one output. Then it should be a simple matter of setting the correct direction for ail/ele

The thing is, that the manual says that if you are programming a delta, v-tail (and one more) you have to program it without any mixing at all. The S8R will do all the mixing.
Don’t ask me why?
And if you ask me anyway, I’d say it’s pretty stupid. Not all delta wings are built the same way….
I wish I’d read the manual before I ordered an openTx radio, if it turns out half the functions are preprogrammed and not left up to you after all.

 

[Mik120]

Oh, I haven't setup the gyro rx with a delta, but this isn't like a "controller". For example, on my helicopters I use a 3 axis gyro and all the mixing is done there. The gyro here is not that. My suggestion is to turn off the gyro feature of the receiver and get the mixing right first, then turn on the gyro and set it up.
If you disable the gyro, the radio setup should be simple. Elevator should move both surfaces in the same direction, and if not, reverse one output. Then it should be a simple matter of setting the correct direction for ail/ele

Solved!
I changed the order of channel/function
So instead of channel 1 being ELE and channel 2 being AIL, it’s now the other way around.
Reversing the servos doesn’t change anything.
But now I have going the same way when applying elevator, which is probably going to make it easier to fly the damn thing
Thanks for your suggestions guys

 

[Mik120]

Oh, I haven't setup the gyro rx with a delta, but this isn't like a "controller". For example, on my helicopters I use a 3 axis gyro and all the mixing is done there. The gyro here is not that. My suggestion is to turn off the gyro feature of the receiver and get the mixing right first, then turn on the gyro and set it up.
If you disable the gyro, the radio setup should be simple. Elevator should move both surfaces in the same direction, and if not, reverse one output. Then it should be a simple matter of setting the correct direction for ail/ele

Solved!……again
So, I thought I’d solved it, but it turns out that the solution done at the dinner table (with 2 other servos) didn’t work any way.
The thing is that the 2 servos in my delta wing, are different makes, and they don’t have the same direction of throw when given the same signal
So actually, the tx and rx where doing it right, but I have a servo that is doing it wrong
I’m embarrassed that I didn’t see that before, but hey…you live and learn right?
Sorry guys, it was a 50” problem

 

[gnichola]

LOL. I have my Tx channel order in Futaba" mode, aileron, elevator, throttle, rudder. How is yours setup? Now you just have to make sure the corrections go the right directions. Good luck to you!

 

[Mik120]

Same as you I’ve been using a FC28v3 for the last 25 years. I was more of a heli-guy
So the transition from FM to digital and
OpenTx has been a little harder than expected

 

[jseyfert3]

Oh, I haven't setup the gyro rx with a delta, but this isn't like a "controller". For example, on my helicopters I use a 3 axis gyro and all the mixing is done there. The gyro here is not that. My suggestion is to turn off the gyro feature of the receiver and get the mixing right first, then turn on the gyro and set it up.
If you disable the gyro, the radio setup should be simple. Elevator should move both surfaces in the same direction, and if not, reverse one output. Then it should be a simple matter of setting the correct direction for ail/ele

Actually, the S8R is exactly like your 3-axis gyro, and all mixing (and reversing) for delta/flying wings (or V-tails) is done on the receiver.

If you use any of the stabilized FrSKY receivers, DO NOT reverse servo throws on the Tx the way you would on the OUTPUTS page if you use a normal receiver. If the servo is moving the wrong way, you must use the STAB lua script on the radio to reverse the servo in question at the receiver. This script programs settings on the stabilized receivers. Alternatively you can use an app or a USB adapter and computer program.

Why? Because reversing the servo at the radio will cause it to move the right direction if you move the stick, but the receiver will still move it the wrong direction for gyro or autolevel modes. In other words, the receiver always says that up is "this way", but if you move your stick and up elevator gives you down elevator, and reverse this on the OUTPUTS page, when you move your stick the output will now be "that way" instead of "this way", but when the gyro/autolevel engages, it'll still say that up is "this way", which is now backwards from your stick movements. And things will go bad quickly. Hence, you must leave the reversing normal at the radio, and if a servo moves backwards change the receiver reversing settings to change the servo direction.

You do not want to disable the gyro for setup. You must leave this engaged during setup. More specifically, you leave the auto-level engaged during setup. Once you verify that all controls move the correct directions with both the sticks and auto-level system, you're good to go and can engage/disengage the auto-level/gyro as desired.

Solved!
I changed the order of channel/function
So instead of channel 1 being ELE and channel 2 being AIL, it’s now the other way around.
Reversing the servos doesn’t change anything.
But now I have going the same way when applying elevator, which is probably going to make it easier to fly the damn thing
Thanks for your suggestions guys

Glad you got it fixed. Note that the manual also specifies that for delta/flying wing, AIL is channel 1 and ELE is channel 2. So you were correct to flip these channels.

See my above explanation for why servo reversing, if needed, must be set on the receiver and NOT on the Tx OUTPUTS page. You set reversing per channel via the lua STAB script on your TX (or phone app or computer, depending how you prefer to setup the stabilized Rx settings). I just went through the setup on my SR8 (which appears to have the same setup and channel order as the S8R) last night, so let me know if you have questions and I'd be happy to help.

Before you fly, be sure to not only check that the controls move the correct directions, but also engage auto-level mode and move the plane. Verify the control surfaces move the correct directions to level the plane as you tilt it away from level. For example, tilt the plane as if it was in a left hand turn, and the elevons should move to force it into a right hand turn. Tilt the nose up, and the elevons should both move down to try to force the nose down. And vise versa. If not, do not fly until this is fixed!

 

[jseyfert3]

Oops, I must correct my above statement. I just performed the final setup and check of my SR8 Rx, in a regular plane. You may, in fact, need to use the reversing in the OUTPUT page on the Tx. So, what you really need to do is what I outlined in my other thread:

I think I figured it out. Vertical was right after looking at the picture on the script and the coordinate system. Aileron and elevator were moving backwards when they were inverted on the controller, but correctly with my stick. So I went to OUTPUTS page, inverted aileron and elevator, back to the script, set them to non-inverted. And bingo. Now they moved correctly both when I tilted the plane, and when I moved the sticks.

The odd aileron flip-flop when tilted just past level either way was when I incorrectly switched mounting direction to vertical reversed, because the controller now thought the plane was upside down, so it was putting in max ailerons to try and level the plane, but doing it in the direction that would get it level the quickest.

It all makes sense now.

Step 1: Ensure mounting matches how you have it mounted.
Step 2: Enable auto-level. Pitch and roll plane. Watch ailerons and elevator. Ensure they move correctly to level the plane. Yaw plane, ensure rudder moves to give opposite yaw. If not, invert channels as appropriate in the lua script.
Step 3: Move sticks. Ensure controls move in correct directions. If not, invert in radio OUTPUT page.
Step 4: Double check your work.

In other words, start with all outputs in normal direction. Enable auto-level, verify controls move properly. If not, check the mounting direction setup in the Rx, and if that's correct, invert the servo directions on the Rx side. Double check auto-level now moves the controls properly.

Once this is done, check stick movement. If reversed, now go to the OUTPUT page and reverse the channel direction. Double check both stick and auto level response moves in the correct directions.

You have to start with the auto-level directions, because inverting the output on the Rx swaps both the auto level output and the stick output. Whereas inverting the output on the OUTPUTS page only inverts the stick output, not the auto-level output. So if you try to set up the outputs in the correct directions before verifying the auto-level output, your stick moves correctly, then when you invert the auto-level output to make that work your stick moves backwards.

I suppose you could start by ignoring the auto-level, inverting the channel on the OUTPUT, then check auto-level. But if the auto-level is wrong, after you reverse it you have to go back and re-reverse the direction in the OUTPUT page. So it's easier to set the auto-level direction first, then set the OUTPUT direction second, as it saves you a step.