Fun with the DJI Phantom

One guys experience!

...Tiger

I tested my hexacopter by switching the transmitter off while in a low flight about 100 yards away because I always wondered what would happen if it lost signal. It falls. Immediately. I learned that I need to investigate some kind of fail safe.

That is spektrum's fail safe, to fall.

LOL. Spektrum's fail safe is to fail.

I thought your flight systems, controllers weren't supposed to that or to return home when a problem arises
... What am I missing? LOL, enlighten my ignorance What is supposed to happen?

It's my interpretation of the Spektrum Fail Safe is to stop the aircraft from flying off never to seen again. Safely landing autonomously after a connection failure was never a trick, a feature Spektrum offered it's users.

-w00d​

...

Well we have RTH (return to home) and "Fail Safe", they are two different things entirely but can be combined. On my setup, a Spektrum DX7SE transmitter, I have programmed a switch to initiate a RTH. This comes in handy if you lose visual on the model so you can flip the switch and have the model return to where it took off. For this RTH to function you need to have control signal at the model.

Fail Safe can be a few things but in the context we're discussing it is the behavior of the model when it loses control signal from the transmitter. Ideally, for me anyway, would be to have the model perform a RTH when the control signal is lost. Unfortunately this is not something that Spektrum thought was important in the design of their radios. As I understand the situation as far as Spektrum systems go this is a function of the receiver on the model, not the transmitter. The receiver I am flying currently does not appear to have this capability.

As my setup is currently configured, and according to the results of the test I made, when the control signal is lost the model basically drops.

With Spektrum's so called 'Fail Safe' mode I guess the way they see it, it's just the lesser of two evils,
ie; Flying-off into the unknown, NEVER to be seen again or to simply drop it out of the sky where the probable damage can be quantified.
... Neither outcome is ideal but it-is what it-is A choice: LOSt model and lost $$$ verses a PILE busted aircraft !?!

Just one more reason I fly FUTABA!

...Tiger

John, can you tell me how Futaba implements Fail Safe? How are you using it on your setups?

I'm not using it, but I should be. How it works depends on the receiver you are using. If I use my 10C in 7 chan mode (cheap receivers), it only gives me programmable failsafe control of the throttle channel. At least with that you don't free fall with zero throttle. On higher channel receivers, there is a failsafe menu that lets you specify the position of every channel individually during failsafe. That will let you program anything you could possibly want.

Was poking around and found this link about a guy doing failsafe with a DX-7/DX-8. You might take a look at posting #14 on this page:

http://forums.openpilot.org/topic/10541-how-to-setup-fail-safe-on-dx7/

...Tiger

Fail safe is something you "set" on a nicer radio and Rx combo. You set it to be whatever it needs to be to do what you want it to do. On cheap DX6i stuff you just get what it is out of the box, no choice, it just closes the throttle so the airplane crashes nearby. All the fpv style Tx stuff allows almost every channel to be set however you want.

I read that post and I seem to recall reading and discussing something like this some time ago. I know there is some hokey (in my mind anyway) method to program a Fail Safe in Spektrum, but what I was looking for was where and how Futaba does this better.

GPS - I just took a picture of the FailSafe screen on my 10C. Maybe this will make it a little clearer. You can set any of the channels to go to any position when it goes into failsafe condition (loss of signal). If you don't program a position, it remains in Normal (NOR). I set the throttle to 20% so you can see what that looks like. You'd probably want to program chan 7 or 8 to trigger the NAZA into failsafe for Return To Home.

...Tiger

That's exactly what I wanted to see, thank you Tiger. Is "NOR" referring to the three position switch setting?

NOR just means that you didn't program a specific action for that channel so it doesn't do anything special during failsafe. There are no switches involved in the failsafe (loss of signal) function. That would be pointless since if you have no signal, you have no switches! The way it works on the screen is you scroll to the channel you want to set, then turn off NOR (to activate) and dial in the setting you want for that channel. You can make any channel go to any position.

...Tiger

Yes, That is how I understood it. Of course you can't flip a switch when you've lost signal. On Spektrum the three position switch has a "NOR" (normal I presume) and I was wondering if that could be set/changed when the signal was lost. It looks like the answer is yes. You can program any switch positions to occur on Fail Safe. In my case one of those switches would be the RTH. Thank you for the explanation. I wish I knew then when deciding on my radio what I know now. I guess multirotors were not really happening then though. The way this stuff advances waiting another year will only bring more new features and goodies.

Yep! This is how they keep us on a constant upgrade path. I see Futaba has a new series of radios now. Don't know what that's about. Just hope I don't need what they have. I have two 10C's and hope to take them to the grave.

I've been thinking about a way (simple hardware add-on) to trick the Spektrum and the cheap Futabas into doing the RTH. We'll see how that goes.

...Tiger

Trick a stock radio and receiver, or trick the radio to trigger a Naza?

Trick the radio to trigger the NAZA.

...Tiger

You don't need to have a hardware ad-on for that if your radio is programmable. You can just set it to a switch. Even Spektrum can do it.