General Align T-Rex 250 FBL (3GX) + Taranis

O

ore22

New Member
Alright, I'm a beginner so please be patient with me :)

I recently got the T-Rex 250 Pro DFC and a Taranis for myself since I wanted to start a new hobby (I have some experience with quad-copters and very small easy helicopters).
Yet, I am stuck now at the moment since the Taranis is quite a beast and the 3GX is as well. I think it all boils down to me not exactly understanding what the 3GX does and how it needs to be controlled.

What I have done so far:
* I built the helicopter according to the instructions and no parts were missing or too much :)
* I hooked up the X8R receiver to the 3GX and performed the binding process between the taranis and the receiver (it appears to be working)
* I watched the Youtube Video from rc-help.com, especially on the DIR mode (which I was successfully able to enter).

Yet, I was not able to get the behaviour which is shown here: (I added the exact time).

Now for a basic understanding and just to see if I got this right:
* In DIR mode, the output from the TX is simply put through to the servos
* Although it is a FBL system, I need to mix the inputs on my taranis to get the correct outputs for the servos (at some places I read that I must not mix outputs, others say I need to). To do this, I set the swash type to 120° in the Heli menu and I am using CYC1,2,3 outputs assigned to the various channels
* I would like to use Mode 2 (my TX is setup for that mode), which means that left stick up/down is throttle, left stick left/right is rudder, right stick up/down is nick and right stick left/right is roll. Why does the video show that if I move the left stick up/down in DIR mode will move up/down the whole collective. Is this some special thing of the DIR mode and once I leave the setup it will behave normally (THR)?
* I am quite sure that I got the assignment between CH1,2,3,6 and the CYC1,2,3 wrong. I guess I will need to set them up so they behave like in the video - is that correct?

- - - Updated - - -

Obviously I am not able to edit my post. I did not mean to add the video inline, just the link:Sorry for that (in case it doesn't work again, the behaviour I mean is at 2m 28s)
 
Last edited by a moderator:
O

ore22

New Member
Alright

In the meanwhile I have found out that I need to set the option in the Heli Menu for "Collective Source". I would still be happy if anyone could answer the questions, just so I get the right idea.
 
murankar

murankar

Staff member
I am not much of a 3gx guy buy do know something about your radio. I have a th9x flashed with er9x.

If the 3gx does all the mixing of the swash then you will want to have a heli setup in the radio. You will also need to use zero mixing in the setup menu.

There are people on here with that radio that may very well have a 3gx. If they don't answer up I will have to post a screen cast I guess. I won't say its easy but its definitely learnable. Let me see what I can find for you. I do have a saved file but it may not work for you.

Sent from my LG-E980 using Forum Runner
 
O

ore22

New Member
muranker, thanks for your response


Yesterday evening I got a little bit further. I would like to add this information for other Heli Pilots (+ there is another question at the end)

My gear is:
Align T-Rex 250 Pro DFC (Flybarless)
FrSky Taranis TX
FrSky X8R RX (connected via S-bus to the 3GX)

I have setup the Taranis as follows:

  • Swash Type: 120
  • Collective Source: THR
    [*]Swash Ring: 0
    [*]Collective Pitch Direction: Invert


For the Mixer I have set the following settings:
  • CH1: -100% CYC2 (Aileron)
  • CH2: 100% CYC1 (Elevator)
  • CH3: THR
    [*]CH4: RUD
    [*]CH6: CYC3 (Pitch)


By using these settings (+ I needed to set the Default Channel Order to AETR (this should be Futaba-style)) I was able to get the correct behaviour for my heli and to make it through the DIR setup.

Yet, I am currently stuck at the Governor Setup (basically which tells the 3GX the stick position for full and low, not really a speed governor in that sense).

When I setup my Taranis, I reduced the THR Input down to about 32 (of 100), since otherwise the pitch would (by far) exceed the 11° maximum deflection pitch the 3GX, respectively Align specifies for "normal" flight.

Yet, when I perform the Governor Setup (keep "Set" button pressed until all lights light up upon powering on), I am successfully able to get through the setup and the 3GX will reset (which is what it should do). Yet, when I re-power the ESC, I only get a continuous beeping from the motor/ESC (beep beep beep beep ...) until I disconnect power. The rotor will never turn. So I guessed that this would probably be an invalid setting for the ESC (too little deflection). I then quickly made a new model and only assigned THR at 100% and immediately the rotor would start turning (after performing the governor setup again).

Currently I am thinking the following:
The deflection for pitch would actually be ok at the 32% setting, but it is not ok for the throttle (throttle should get 100%). Since I reduced it in the Input settings, I reduced the setting for the throttle stick. Yet, in fact I should set the output which is then given to the servo. I will try that tonight.

If you have additional thoughts in the meanwhile, let me know.
 
O

ore22

New Member
Alright, I'm still not quite sure if I'm going into the right direction, so please correct me if I am wrong.

Apparently I need to output different values for the Throttle and the Pitch channel. I tried setting the Pitch channel to limit it to certain values, but this makes the swash plate move strangely, since the pitch and ail/ele need to go in unison up/down. If I limit them as well, I do not get the desired deflection anymore (there's just too little movement possibility since everything is restricted).

That means to me that I will find a way so that Collective Source Input is basically the throttle stick, but I would want this to be limited; the output for the throttle should be 100% max.
 
murankar

murankar

Staff member
The very first thing is your radio needs to be at:
Swash type: 0.

On a normal radio this translates to a 90° single servo. So if the 3gx is a 90° single servo gyro (which i think it is) then make sure you do this. Once that's done then you can move on to the rest if the radio.

For the curves it does not matter what order you do things. What does matter is you remember what number is for what. I think my first three curves are throttle and my next two are pitch and the last is for throttle hold with zero throttle.

Next as for channel assignment it really doesn't matter as long as you know what channel is what. Best practice is to stick with either Specktrum or futaba. Which ever use stick with it. I use Specktrum style layout.

Later tonight I will post the file from my radio to the forum. Now you will need eepe to view it. Once you open the file you could mimic my settings. Now I will have two models in my file both for a Gaui X3. One is for ZYX-S (which is a 90° single servo) and the other is for a beasts clone (same as other 90° single servo). You should be able to copy and paste from one to the other.

For Tony; where should I post my zipped file for my radio setup?

Sent from my LG-E980 using Forum Runner
 
Last edited:
Tony

Tony

Staff member
Uri, post it in here. If this is NOT a spektrum file, then you will need to put it in a .zip folder for it to upload to the forum. You can do it within your Manage Attachments after you click the Advanced tab in the reply.
 
murankar

murankar

Staff member
Its going to be an eepe file which I think is a .eepe file. Okay then once I get settled down I'll post it up. Today has been a whirlwind for me.

Sent from my LG-E980 using Forum Runner
 
O

ore22

New Member
@murankar:
According to many videos on Youtube, with the 3GX the Swash Type needs to be set to 120° 3 Servo mode. I am nearly sure this is correct, although the manual states "While using 3GX FBL system be sure to turn off the following functions in the transmitter: Swash Ring, Linkage Compensation, Swash Mix, Mixing, Acceleration".
As far as I understand the 3GX differs from other Gyros in that it doesn't do the mixing of the servos by itself but relies on the TX (which maks the configuration of a 3GX on the Taranis so inherently different from other gyros such as Microbeast).

I have gotten even a little bit futher now. I do now have my input from the throttle stick. This input is passed on to CH17 (which is a "virtual" channel). The pitch setting will take its value from CH17 and output it reduced to around 32% at channel 6 (which is pitch). The throttle channel (#3) takes its value from CH17 as well (but it takes the full 100%). This appears to work as I want it to since now I am able to move the collective in the desired direction (with my limits obeyed) and I am also able to successfully initialize the motor/ESC.

Hopefully I will get additional tools tomorrow (swash plate leveler + set of screws; mail takes an eternity here), then I will be able to exactely test my setup and to fine-tune it. I'll keep you posted on my progress.
 
murankar

murankar

Staff member
Yeah with turning off swash miking means the radio is set for 90° single servo. Swash ring is a Futaba thing that was incorporated into er9x and open9x.

To get back on track. The 3GX will do all the mixing instead of the radio. This kinda complicates things for open 9x from a programing aspect. Its not complicated once you see what's going on.

Let me get my file posted so you can see what I mean. I am at the grocery store getting dinner atm.

Sent from my LG-E980 using Forum Runner
 
murankar

murankar

Staff member
ore22 said:
@murankar:
According to many videos on Youtube, with the 3GX the Swash Type needs to be set to 120° 3 Servo mode. I am nearly sure this is correct, although the manual states "While using 3GX FBL system be sure to turn off the following functions in the transmitter: Swash Ring, Linkage Compensation, Swash Mix, Mixing, Acceleration"...
Click to expand...

I highlighted the two key facts that make this a contradiction. You cant have the swash mix turned off and set for 120 degree 3 servo mode at the same time; unless there is an option in the 3gx software that allows you to set 3 servo 120 degree. Now I know with the Tarot ZYX-S gyro you have mixing turned off in the radio and in the gyro software you set the gyro to 3 servo 120 degree and that's how the mixing is done.
Here is a screen shot of the ZYX-S swash setup:

servo-setup-screen.jpg

As for the radio you cant have both programed in the radio, its one or the other. You will see below how to turn off Swash Mix and this is what tells me that the 3GX does the mixing instead of the radio. Your radio will not be doing a whole lot, most of the work is done by the gyro.


ore22 said:
I have gotten even a little bit futher now. I do now have my input from the throttle stick. This input is passed on to CH17 (which is a "virtual" channel). The pitch setting will take its value from CH17 and output it reduced to around 32% at channel 6 (which is pitch). The throttle channel (#3) takes its value from CH17 as well (but it takes the full 100%). This appears to work as I want it to since now I am able to move the collective in the desired direction (with my limits obeyed) and I am also able to successfully initialize the motor/ESC.

Hopefully I will get additional tools tomorrow (swash plate leveler + set of screws; mail takes an eternity here), then I will be able to exactely test my setup and to fine-tune it. I'll keep you posted on my progress.
Click to expand...

I would have to see your file to understand whats going on there with the throttle. It sounds like its setup the hard way. All of my throttle settings are mapped to channel three through the Mixes and Curves menus. My Collective is on channel 6 and handled through the Curves Menu just like throttle. The only Virtual channel you should need is for throttle cut and that's actually more of a virtual switch than a channel.

Really look at the file I linked here. It should help you out. I got the basic file from the openTx forum that handles all the tech support for the *9x firmwares minus the one HK used for the TH9XR.


Here is my eepe file. Unzip and open in eepe not open9x.

View attachment gauiX3.zip

Start a new model and use templates:

  • T-Cut
  • Sticky T-Cut
  • Heli Setup

Next follow the tabs in order

Setup: should be easy enough to follow. Leave all the defaults. The only thing that you could change is the timers.

Heli Setup:

  • Swash Type: Off
  • Collective: CH11 (not sure how this effects stuff since I have nothing on CH11 in my mixes tab).
  • Swash Ring: 0
  • Invert: Nothing checked

Modes: Skip (not sure what this is.

Expo/DR: Follow what I have or use your numbers if you what those are. This is going to be set to what you like to fly with. For my X3 these numbers are fine.

Mixes:This is your channel assignments. This screen will assign functions to the actual channels. I have a mode 2 Specktrum rx layout. So this is what works for my heli. I flew at Hotter-n-Heli earlyier this year and this setup worked just fine. CH5 is your gain channel for head hold and rate modes. The P2 you see is for pot 2. that knob will adjust the gain of the gyro for the tail. Once that is set you can use hard coded numbers later on. CH6 is your three pitch curves listed on the Curves tab (curves 4 and 5; and 6 is for throttle hold) CH14 uses virtual switches to get throttle hold to work. It is tied to the Switches tab (more on that later)

Limits: This will be set custom to your heli setup with the 3GX firm where. This screen is also how you adjust your pitch ranges and servo travel. First on deck servo travel; the offset column is used to reverse servo travel. Min and Max columns set the actual pitch of the blades. Ch6 sets the collective range for positive and negitive pitch. CH1 and CH2 will be used to set the 8 degrees referance for the 3GX. This is best done on the radio and not the software.

Curves: 1 and 2 are throttle curves and 4-6 are pitch curves. Curve 6 is used for throttle hold setup and autos if you get to that point in flying. Although with the 250 you wont be doing any real autos due to lack of weight and enertia.

Switches: CSwitch7 through CswitchC is setup for throttle hold. Make sure its set just like it is here. It should be if you use the templates.


That should complete the radio setup. If you have any other issues let me know. I will do the best I can and now that I have this file and explanations maybe the 3GX owners can help out also. If some thing is not clear enough please let me know.

PS
I also have my realflight 7 model in this file. As of right now it works but I think it could be improved. I got throttle hold mapped, the f mode switch is mapped and all you have to do to get it to work is make sure in real flight 7 you turn off software mixing and let the radio do all the mixing.

servo-setup-screen.jpg
 
Last edited:
O

ore22

New Member
@murankar: Thank you for the setup instructions, I will try this within the next days (tools arrived today).

Can you say something why e.g. this guy: Align T-rex 450L 3GX Setup - YouTube (at around 1:10) states that it needs to be 120° swash type (3GX with a larger T-Rex 450)? Maybe I'm getting this wrong (english is not my native language or maybe I'm confusing the vocabulary regarding swash mix ...)?

Thank you so far for your support. I really appreciate it.

- - - Updated - - -

Two more facts:
* The software doesn't have a setting possibility for the swash type.
* The manual states the following:
* Step 1.4: Collective Pitch Setup: Adjust the maximum collective pitch using the transmitter's swashplate mixing function (pitch swash AFR). (...)
* Step 1.5: Adjustments to the CCPM servos endpoints should be done through transmitters swashplate mixing function (AIL swash AFR). (...)
* Step 2.2: (Swashplate mixing type recognition and elevator endpoint setup): With all channels stationary, move the transmitter elevator stick forward, and then back to center position. This completes the swashplate mixing type recognition process. The control unit will determine the CCPM mixing ratio or traditional mechanicalmixing maximum elevator endpoints.

- - - Updated - - -

Not sure if I am allowed to upload files, so I put my current configuration here: http://1drv.ms/WpjIYm
 
Slobberdog

Slobberdog

Well-Known Member
You have to set the swash type to 3 servo 120 deg in the tx, mixing is done in the tx not in the gyro!
 
Slobberdog

Slobberdog

Well-Known Member
Wish I could help you more fella but not got the info on setting up the taranis, the 3gx is not to bad to set up but can't get a good manual to point you in a good direction on the tx
 
O

ore22

New Member
@Slobberdog: Don't worry. I am just confused since murankar tells me I must not do mixing in the TX and you tell me that I need to.

I just tried following the instructions (Swash Type: Off) but when I'm in DIR setup mode, only single servos will move upon input from the Throttle/Pitch stick. The swashplate doesn't move as it should (up/down). Is it possible that the 3GX is so much different from the ZYX-S murankar uses?
 
Slobberdog

Slobberdog

Well-Known Member
Yes the 3gx is totally different to the zyx, as I said the 3gx does not do the mixing it has the be done in the tx
 
Last edited:
You must log in or register to reply here.
Top Bottom