Naza M Lite Fail Safe RTH...with AR6200?

[John7845]

Right Guys,

just had a mess around testing Pre-set and hold fail safes.

Looks like the AR6200 only does hold :((

Tried doing Pre-set, but all channels go to hold (last known position) and throttle channel will go to fail safe position.
Same with all other attempts.

But, throttle channel will go to pre-set fail safe position, meaning the heli set up will be viable?

Im not quite sure how this heli set up works yet, but I'll watch the video above.

Im still now pondering weather to go with an Orange Rx or Heli set up.


The thing with the orange rx is I just don't trust them long range.

They seem so cheap and tacky, I just don't think they'll perform as well as a AR6200 long range????

[John7845]

Hang on a second, for the heli mode, don't you still need an Rx that can preset, so can hold on all channels,
meaning when tx is off, it will go into 'throttle hold mode' and failsafe?

With AR6200 this would not work, as only throttle would hold, no matter which position the 'throttle hold' switch was in.

[jamesb72]

Isn't this where we started !!! Read back from the top again ;)

[JoeB]

I'm just about setup my NASA so glad I found this.

[John7845]

Your Bang on James/

Looks like the only option is to go for the Dreaded Orange Rx :((

[Spanner]

Wrong, you CAN do it, but you need to drive the throttle of the NAZA with the pitch/ch5 (hence the reason for setting up as a helicopter) and use the throttle o/p of the rx to drive channel U (using flat line throttle curves to select which flight mode you want), which is the only channel that needs to be driven in failsafe in the event of signal loss.

I promise you, it works! No need to buy another rx.

I'll write a "how to" tonight, off to work now :(

[John7845]

Will do. Thanks.

Stuck between new Rx or Heli mode?

Not sure which is worth more hassle.......We'll see.  :-\

[_tj_]

If you don't trust or like orange, buy a spektrum rx that failsafes. personally I've never crashed with an orange rx, I've had a couple that haven't worked when they have arrived.

Sent from my GT-I9300 using Tapatalk

[Spanner]

Right, a long post, I've read it a few times and it makes sense to me, I hope it does to you !!!


Firstly a little about programming your radio and how it differs between Heli and Fixed wing, what preset and normal fail-safes are. I'm basing this on a Mode 2 set-up, if this works with other modes then great, but I don't fly in any other modes, and haven't set anything up in other modes, so can't guarantee it'll work.
 
In a normal fixed wing configuration you'll have all the functions that you are used to, Aileron, Elevator, Rudder and Throttle. The Aux outputs can be configured to various switches but normally drive flaps or undercarriage for example, depending on how many channels your Tx/Rx supports. So in FW mode, the sticks (unless mixed with something else, but not relevant in this case) will only drive one channel.
 
In heli mode it differs quite a bit, but generally only in the background/programming. You still have your normal aileron, elevator and rudder functions, but the throttle works differently to a FW set-up. In a helicopter to go up we increase the collective, or pitch of the main blades and also increase the throttle at the same time to compensate for an increase in demand from the rotor head (a generalisation, but for this explanation it's fine). So on the throttle stick, unlike a FW set-up, you have two outputs/channels. One for Throttle (Thro) and one for Pitch (Aux1), both of which can be modified by throttle/pitch curves. Different curves can be set-up then selected via the flight mode switch. (Idle Up in model heli speak. Labelled Norm, ST1 and ST2 in JR radios) So when you select ST1 the curves can be completely different to that of Norm, similarly ST2 can be completely different to Norm and ST2, depending on how you want the heli to fly.
 
The other consideration to make is swash type, without going into what and how a swash is or works, you just need to know that different brands of radio name the swash types differently, and I could write a whole page/book about how a swash works! In your Spektrum radio it needs to be either 1 servo, Norm or 90'.
 
So, receivers and fail-safes. Using a receiver that is able to have a preset fail-safe, you can initially bind the receiver in a special way        with the sticks, switches, trims, gains and curves at whatever position you would like them to be in in the event of a total signal failure. You can then rebind as you would normally, return the sticks and switches etc for normal flight and fly happily all day long!
Other receivers don't offer this preset functionality, and it appears that your AR6200 doesn't. It does however, support fail-safe on the Throttle channel, or Normal fail-safe. You can set the throttle channel to a position, bind the receiver, and this position is remembered. In the event of signal loss, the throttle will drive to this bound position with all other outputs holding at the last demanded position. Great for a glider, but not so great for our multi-copters!
 
So what does your Naza need in order for the RTH fail-safe to work? The only channel that controls the fail-safe is channel U, so we need a method of driving this channel to fail-safe in the event of signal loss. Which, if you connect your Naza to your receiver in the way that DJI say, will never happen with your current receiver. You can try all sorts of bind methods, but the only channel that is able to achieve a fail-safe of any sort is the throttle channel.
 
So, as an experiment, connect your Naza as DJI specify, with the 3 position switch coming from Aux 1 on the receiver. Then create a new model, but this time, as a heli with the 90' swash type. Bind it at low throttle. Then restart your Tx and power up the model, start your Assistant Software and plug the model in. Then move your sticks and see what happens? You'll notice that your Ail/Ele/Rud will move as you expect, as will your throttle, but you'll also notice that one of the sliders will be moving sympathetically with the throttle, Channel U. Now turn your Tx off and you'll see that the throttle will be driven to the bound position.
 
SO, now unplug the throttle input from the Naza, and connect it to the U input of the Naza. Turn your radio on and now you'll now see that the movement of the throttle stick will now move the U slider, selecting GPS, Atti, Manual or fail-safe, depending on throttle position.
If you now plug the Aux1 to the throttle input, you'll now see that you can drive the throttle. Now, turn your Tx off. The throttle fail-safe which was bound to low throttle, will now drive the U channel on loss of signal.
 
So, now re-power the Tx and physically move the throttle stick to a position that will engage fail-safe within the Assistant Software. Now this is where you have to be careful not to touch the stick. Power off the model, disconnect from the Assistant Software and turn your Tx off. Now it's a simple case of rebinding the model with this throttle position. Re-power everything, and connect to the software. Now when you turn the Tx off, TA-DA!! You have a model which will, on signal loss, go into fail-safe and return to home!
HOWEVER, you need a way to be able to change the flight modes. You may have to enable the flight mode switch in your model menu (the place where you specify heli/swash etc, check your manual if you are unsure). Then, it is just a simple process of adjusting the throttle curves in the Tx.
 
Put your Flight Mode switch to Normal and your throttle stick to 0% then go into the Throttle Curve menu and then adjust point 1 to a %-age that will give you GPS, with that figure you can then make all the other points the same, you should end up with a flat line across the curve, the ones I have set up are around the 93% mark. If you change the Flight Mode to ST1 it'll come out of GPS, returning back to normal will select GPS again.
Change FM switch to ST1, and adjust point 1 to a %age that will give you ATT, and adjust the other points to the same number.
Do the same for ST2 to give manual mode or fail-safe. You now have 3 switch positions, for 3 different flight modes, if you only have a two position flight mode switch, then adjust according to what flight modes you require. You could configure the throttle hold for instance, to engage fail-safe.
 
And that's it; you now have a model that on loss of signal will engage fail-safe and RTH, and a switch that will enable you to switch between Norm, ST1 and ST2 so you can select GPS/Atti/Manual/fail-safe. All you need to do now is set it up normally within the Assistant Software, go fly and have fun!!

All you have changed is which channel is driving the throttle, in this case the pitch channel. Making the throttle curves as flat lines effectively makes them a switch with three positions at different levels.
 
So it should be connected as follows, Aileron--->A, Elevator----->E, Rudder---->R  Throttle---->U, Aux1----->T.

Your spare channel/s can then be assigned to the X1 or X2,so you can make use of either the remote gain adjust or the IOC functionality, I had to enable governor on one model in order get remote gain, but better than nothing.

Make sure you have the GPS puck plugged in or you won't be able to see correct selection of GPS mode or IOC functions.

******BEFORE YOU FLY, CONFIRM YOU ARE GETTING FULL AND CORRECT FUNCTIONALITY, PREFERABLY WITHOUT BLADES ON!*****

Green - GPS
Orange - Atti
Red - Manual
FLashing Orange - Failsafe

Sorry if this is a bit long, but I got carried away! Feel free to PM me or ask here of you need any further clarification, I'll do my best! Cheaper than a new Rx!
 
Spanner.

[John7845]

Wow, thanks for the detail Spanner, really really good post!

I understand about heli set up, as I have a few CP Heli's lurking about.

SO....just to clarify.

Throttle goes to U port
Aux 1 goes to throttle,


Bind with throttle high lighting Fail safe for fail safe setting when signal lost...that's all good.


The only still sightly confusing part is getting into all the different modes.
Please note the DX6I does not have a three position switch, I am currently using
Gear and Flap switches to control mode..

Could you expand a little upon the block about getting the three/four modes? through heli settings?

Thanks so much,
I am glad you got carried away as the detail is amazing and really helpful.
Thank you for taking the time to explain all this, I am sure it will also help many to come in the future!
All the best,
John. :D

[Spanner]

Ok, getting it into the different modes is a case of adjusting the throttle curves in the different flight modes. They should be enabled by default on the flight mode switch, and from memory your flight mode switch is on the left shoulder of your transmitter? Of which there are only two, Normal and IU1/ST1?. There should also be a Hold switch on the lower right shoulder?

Unfortunately, as you only have a two position switch, this method will only give you two flight modes on that switch, and one on the throttle hold.

With both model and Tx powered on, and the Naza plugged to your computer with the Assistant Software running, you can monitor the position of the Flight Mode slider on Channel U located in the Tx Cali tab.

If you leave your throttle stick at the lowest position, 0%, the slider should be at the very end stop of one side. Now go into the throttle curve menu, by default you should start in normal. Now you can adjust what the output percentage of the throttle channel will be. By default you will be presented with a straight line "curve" running from 0-100%. The curve is split into 5(?) points, all of which you can adjust.

Highlight point one, which will be at 0%, and use your scroll wheel to increase the value. Whilst doing this monitor your Naza software, when the slider gets to the required flight mode, GPS for example, stop and make a note of what percentage it is. Change to point 2 and change it to this percentage, same with points 3, 4 and 5. This will now leave you with a flat line running across at that percentage. I set one up a while ago and from memory GPS was around 93%.

You have now set GPS to be selected when the flight mode switch is in position 1.

Now, in the throttle curve menu, select IU1/ST1. Again this will be a 0-100% "curve". Follow the above procedure, but this time make the percentage of point 1 select a different naza flight mode, Atti for instance?

You have now enabled Attitude mode to be selected when the flight mode switch is ion position 2.

The final flight mode you can select is on the Hold switch, again you can adjust the throttle curve when this switch is selected. I set this as fail safe on a friends radio.

Curves should look something similar to these works of art below!!

    Default                      Adjusted

100|                   .          100|
      |               .                   |____________ 93
      |           .                       |
      |       .                           |
      |   .                               |
   0 |_____________           0  |_____________

[John7845]

Ah yes, I understand now....very similar to one of my heli set ups,

just getting to grips with the idea of pitch doing mode and throttle separate yet linked ;))

My DX6I has three modes I can program as Naza Modes:

Normal
Stunt
Hold

So I can program Normal as GPS, Stunt as Attitude and Hold as Manual.

Then I guess I will have to leave Fail safe for only when the Tx is turned off...as there are no more
positions of the pitch curve I can program to a mode........

Looks good, will sort it tomorrow and report back Spanner?

[Spanner]

Please do mate, hope you get it sorted :)

[Spanner]

Suppose it depends how often you'll fly in manual? I have a friend who I know will never fly in manual, to scared of losing control! So we set his hold switch to failsafe, his "In case of Emergency" switch!

[John7845]

I guess you are right. I never really fly in Manual, mostly GPS and Attitude.

Probably set my throttle hold switch to Failsafe then I think


The only time I tried to take off in manual the quad immediately flipped on its back??

Not sure what caused it but it put me off flying in manual since, Not sure weather it
was prop wash and too slow a take off or a really out COG. I haven't the guts to try switching
into Manual whilst in the air for fear of a never ending death loop!

I think it is because my COG is out though, I will re-center it when I add all my FPV and gimbal gear
in the next few days. :D :D

All good,
John.