I have a new Wookong system that I installed and setup and it flies nice. I use 5.20 firmware as I believe its truly the last reliable firmware.  It flies very smooth and stable in GPS, ATTI and manual modes.  I have been reading and researching how to properly setup the failsafe correctly.  I have set it up so that when my radio powers off, it does go to fail safe in the U channel.  I also have selected altitude go home and 50 meters selected. My question and concern is about inconsistencies about a throttle value needing to be stored in the radio or not. Some people believe that you do not need to store any throttle value and that the flight control system just automatically will know how to land.  Some people believe you need to manually store and program your radio with a throttle value of less than what your normal hover throttle is.  Some people believe that if you don't store a value into it that it will use a value of 0 and throttle will essentially cut off when it tries to land.  So the opinions vary and the Wookong user guide is not specific about the proper procedure.

With all that said I am very confused.   After reading everything so far I would draw the conclusion based on my assumption that you do indeed need to set the fail safe throttle value in the radio because every copter will be different as far as the amount of throttle required to hover because this is based on motor-prop choice and payload.

Now with that said, if this is true I don't know how programming the value into the radio makes any difference because when the radio is shut off or loses connection with the RX the value in the radio is meaningless.  So I ask this question, if you do need to store a fail safe throttle value into the radio upon binding, does that mean it stores this value into the RX so that if the RX loses the TX's signal it will give the wookong the appropriate throttle value?   What happens if you don't program a value would it just use a default of 50% or 0%?

Any help is very much appreciated. I have a very good flyer and do not want to crash a very good working copter.

Thanks in advance.

Dave King                                       

You are right that if the radio is off any values in the radio do not mean much since they are not recognized by the flight controller.  Failsafe will assume auto control of the channels.

I think some confusion may come from some systems where the throttle channel triggers failsafe by going to a value lower than it normally would at zero throttle.
Many receivers allow failsafe programming of the throttle channel where you can set a throttle value for the receiver to output if signal is lost.  Some flight controllers use this as a way to trigger failsafe mode.

You definitely do not want your radio throttle at zero since you might be able / want  to regain control in some instances.  So throttle should remain around its hover point in most circumstances.  As to the receiver most normally default to last position unless you program otherwise.  If anythink I would use 50% - hover in Attitude / GPS mode.

joe@heliflightc Posted at 2015-5-5 21:25
You are right that if the radio is off any values in the radio do not mean much since they are not r ...

Hello Joe and Support

I guess I am still not understanding how it works. Will the stored value in the radio's fail safe be programmed in the RX if the TX loses power?  When the WooKong goes into failsafe is it going to look for a stored value or not? If it does should it be set to hover throttle or a lower throttle? How does Wookong determine landing throttle?

In the manual you should read how to set Radio switches and Transmitter setup.

You have a Mode control switch.  This is the switch used to select flight mode - attitude / GPS mode etc.
You need to program your receiver failsafe so that when thit no longer sees your RC transmitters signal that channel will go to the value neede for failsafe.
You can verify this in the Assistant software

The WKM is just reacting to what signal is sent to it from the receiver.  The receiver recognizes it is no longer getting a signal and sends the WKM the failsafe values you set when setting receiver failsafe.

Hi Dave
just thought i would add to your thread.
Yes you are  correct in setting the U channel (flight mode) to failsafe but there is one other bit to consider.

If you initiate a failsafe by either the U channel (say channel 5 on your radio set) or by a radio signal failure then you enter failsafe but there is a delay before it initiates.
Depending on your radio set and reciever if you have a signal failure then it will either go to a preset failsafe position or hold its last position before failsafe takes over.

For this reason i set all of my channels to a preset position

Flight mode (typically channel 5) set to failsafe position
channel 3 - Throttle to just below mid point (hover)
channel 1,2,4 rudder aileron, elevator to mid stick.

This would mean that when you loose a radio signal and enter a failsafe situation your control inputs and throttle should be nulified before failsafe takes over, it takes a couple of seconds for failsafe to kick in and a lot can happen in a couple of seconds with a multirotor depending on what was happening before the loss of radio signal.

Definitely agree with this.  For a receiver capable of all channel failsafe setting this is the right thing to do.  This should happen by default if you and move throttle to mid point and all other sticks are centered.

Which brings up the point you should make sure you have a receiver that can do failsafe on all channels.

joe@heliflightc Posted at 2015-5-8 21:50
Definitely agree with this.  For a receiver capable of all channel failsafe setting this is the righ ...

Thanks project41 your reply made sense to me at last !!! I've been trying to get an answer to the same question as DAVE KING but using a nazalite f/c ,to be fair it is a little confusing to newbies and a simple explanation goes a long way.The manual says to set failsafe to no less than 10% of endpoint.and i think that's what confuses us  .Easier explanation to me is set rx failsafe at slightly below hover on throttle ch and center stick on all others...worst case scenario craft will descend slowly or naza detects no signal and takes over .i hope i understood you properly.

I think there is some confusion here relating to Failsafe.

If you a flying with a radio system and its standard receiver e.g. like a standard RC fixed wing aircraft) and your radio system supports failsafe then you can program fixed failsafe settings into the receiver (And they are stored on the receiver not in the transmitter). If the receiver loses connection to the transmitter. i.e. gets no radio signal, it will move the servo's to the failsafe position previously configured.

This is failsafe at the receiver.

With Naza and Wookong the Flight control unit is after the receiver and has its own criteria for failsafe. and also return to home etc.

With a Naza or Wookong system you should not program your rc receiver for failsafe. Allow the flight controller to do its job.

Basically programming your RX unit to enable the Rx failsafe via your TX is a bad, bad thing to do if you have an intelligent flight controller.

All you need to do is assign a switch on your transmitter, set its position via the TX configuration settings and the NAZA  /  Wookong assistant software, to assign a spare channel on your RX to enable a manual failsafe return to home switch.

Its all in the clearly detailed in the DJI user manuals.



Cheers