DJI Combined Stick Movement Arming Sequence

[2tall]

Perhaps I'm missing something...

The DJI ESC arming sequence requires that the TX aileron/elevator gimbal be either hard down-left or hard down-right while the motor/rudder gimbal is moved the same way. This starts the props spinning with the ship receiving some pretty ugly control inputs. Using the Naza software I have set the motor start/low speed to the lowest setting within the "recommended" range. I have almost tipped the ship over twice on start-up. I guess I'm not quick enough releasing the aileron/elevator gimbal to its center position. Am I missing something, or is it just a matter of becomming accustomed the the sequence? There sure should be a better way to arm those ESCs.

 

[VINHEX]

I'm not familiar with the Naza, however this does seem a little erratic... Have you checked all the prop rotations are correct, once the motors start, just let go of controls and raise the throttle a little so as not to time out and shut itself off.

 

[jforkner]

The CSC starts the motors, which, of course, assumes the ESCs are armed. I'm running an older version of the Assistant (w/o GPS & no throttle speed adjustment) and when I execute the CSC, the motors start and run at idle for 3 seconds. I haven't timed the duration of the CSC, but as soon as the motors start spinning (a few seconds), I release the sticks. I need to advance the throttle within the 3 seconds to keep them running.

If your copter is trying to fly (i.e., tip over) upon releasing the sticks, perhaps you should lower the motor idle speed.


Jack

 

[mailman35]

sounds like its motor/prop rotation. if the MR wants to flip.

 

[2tall]

I used the Naza software to lower the motor idle speed to the lowest setting. That seemed to help.

Motor and prop directions were all correct, as the ship behaved perfectly in the air. The problem was that the stick position for arming coupled with DJI recommended middle setting for motor idle speed produced a roll before I could release the aileron/elevator stick to center. With the idle speed much lower it is not an issue.

 

[Tahoe Ed]

I have flown the Naza from the first model and software versions to the current with GPS. I have never seen the issue you described. It might help if you would share your setup, motors/esc/tx/rx etc.

 

[2tall]

I have flown the Naza from the first model and software versions to the current with GPS. I have never seen the issue you described. It might help if you would share your setup, motors/esc/tx/rx etc.

Everything on the F550 is stock (motors, ESCs, Naza, GPS) I'm using 3S power with the stock Naza 8" props. The RX is a Spektrum 7010 talking with a JR9503. The throttle curve is linear with no trim or expo, and the end points are set at 100 (as are all the other controls).

Perhaps I simply do not understand the arming CSM sequence, and I'm making it all harder than need be. I'm holding the throttle/rudder stick in the bottom right position and then moving the aileron/elevator stick to the same position. With the motor idle speed set at the software default the motors generated enough lift to tip the ship before I could release the aileron/cyclic stick to its center position. After I changed the motor idle to the lowest position it became a non issue.

Once aloft the F550 behaves very well in all modes. I have the gains dialed in fairly well. My problem was only with arming the ESCs and motors. BTW: arming is a bit inconsistent. Sometimes the CSM works on try one while other times it just refuses to work. Not sure what that is all about.

Jon

 

[Tahoe Ed]

I have a similar set up only I use the 8" props with 4S. If I fly 10", I switch to 3S. When i arm, it is pretty much a simultaneous motion with both thumbs. I move the rudder to the right, the throttle is already at the bottom, and the right stick to the lower left corner. When the motors arm, I release the sticks and then advance the throttle. To me it seems like a more natural motion moving both sticks toward the center of the transmitter.

 

[2tall]

I switched to the 8 inch props after three of the 10 inch that came with the kit failed within ten minutes. The 8 inch versions have been fine for several flights, but probably will not do well with the added weight of landing gear and a light camera. I'm going to order upgraded 10 inch props, or switch to 4S (suggestions either way are welcome).

Getting back to the CSM arming sequence, I fly helis as well. I can't imagine using that CSM sequence to get a heli rotor spinning with a hard start ESC. New blades, masts and feathering shafts would have me in the poor farm. :tennis:

 

[Tahoe Ed]

I fly helis as well. The DJI products were not set up like this in the beginning. You could use throttle hold and the motors started when you increased the throttle. There was a small but very vocal group that demanded DJI add the feature. DJI finally did so about the third version of the software. I was sad to see the change, but oh well what can you do. I like the 4S - 8" props for the F550 and the 3S - 10" for the F450. It is a pretty personal choice. I like the flying characteristics of each craft with those combinations. I find the F550 is very twitchy in the wind with 10" props and low weight.