5 minutes, wobble begins, then....

hangloose

Member
Hello,

This is my first real post here after lurking for awhile and reading a lot of the advice given here. You all seem like a friendly bunch so here goes..... I recently purchased a barebones DJI S900 setup and paired it with a DJI A2 purchased separately a few months back. My transmitter is a Taranis X9D. Assuming for a moment that all of my settings were correct, why would my maiden flight end with a wobble, loss of control input, flip and crash straight down into the ground.

Thoughts, questions?

Thanks in advance,
Frank
 

hangloose

Member
I should have also mentioned that I started off in manual, then switch to ATI shortly after take off, then switched to GPS/ATI towards the end of the flight when all hell broke lose.
 

Hoki

Member
MYbe all the switching in flight makes it funnny. I know my drone will wanna flip n act wonky if my transmitter battery is low
 

hangloose

Member
I considered the transmitter after the crash and looked at all of the switches and the gain setting dials. I didn't check the battery since it was a freshly charged 2S.

I think that I'm done with building anything of this size on my own at this point. Is there a log or something somewhere that I can pull off of the A2? I can't seem to find anything specific to whether or not log files are even available without some type of advanced configuration to capture them.
 

jbrumberg

Member
Hangloose-

Welcome.

Out of curiosity did you calibrate the compass and give the flight controller time to initialize and get a GPS lock prior to launch?

Launching in manual mode would n0t involve the GPS and I am not positive, but probably also the accelerometers.
 

hangloose

Member
Hangloose-

Welcome.

Out of curiosity did you calibrate the compass and give the flight controller time to initialize and get a GPS lock prior to launch?

Launching in manual mode would n0t involve the GPS and I am not positive, but probably also the accelerometers.

Good catch. During the preflight, prior to arming, I was able to verify zero lights flashing while set to manual mode, and when I switched to GPS/ATI mode the led would flash 1 red light or no lights. The compass was calibrated. Also I had the ground station running and there were no alerts prior to take off that led me to believe there was an issue with the GPS. Keep the questions coming in the hope that I can figure this out.
 

Benjamin Kenobi

Easy? You call that easy?
Hello,

This is my first real post here after lurking for awhile and reading a lot of the advice given here. You all seem like a friendly bunch so here goes..... I recently purchased a barebones DJI S900 setup and paired it with a DJI A2 purchased separately a few months back. My transmitter is a Taranis X9D. Assuming for a moment that all of my settings were correct, why would my maiden flight end with a wobble, loss of control input, flip and crash straight down into the ground.

Thoughts, questions?

Thanks in advance,
Frank

Hi mate,

It could of been so many things on a maiden flight.

What was the IMU orientation setting in the assistant program? Or the compass direction?

How come you were taking off in manual mode? ATTI mode is preferred due to the inherent instability of the system.

Transmitter settings? Verified correct direction in the assistant program?

Did the ESCs all sound like they started properly?

Lots of questions....sorry! :)
 

hangloose

Member
Hi mate,

It could of been so many things on a maiden flight.

What was the IMU orientation setting in the assistant program? Or the compass direction?

How come you were taking off in manual mode? ATTI mode is preferred due to the inherent instability of the system.

Transmitter settings? Verified correct direction in the assistant program?

Did the ESCs all sound like they started properly?

Lots of questions....sorry! :)

The IMU orientation was pointed towards the front of the craft, it was aligned perfectly inside the outline etched onto the center-chassis bottom plate. The assistant software confirmed that the orientation was correct.

I'm confusing manual with ATTI, I do take off in ATTI mode on my F550 clone, however I usually use P-mode with my Phantom 3 Pro. So yes, I used ATTI mode to lift off with this rig.

As for the transmitter settings, I do remember verifying as well as calibrating the sticks. Other than the yaw being a bit twitchy with the recommended gain settings, the rig was responding very smoothly to my inputs on the sticks in all directions. It was flying beautifully and I was excited and then boom.

About the ESCs sounding like they started properly, that's a good question because I'm not sure what I would have compared that to. All of the motors were spinning consistently. On the subject of foldable propellers, the one thing that bothered me was the lack of explanation in the DJI documentation (at least that I could find) as to whether or not I needed tighten them so that they were fixed. I know that defeats the purpose of foldable props, but as someone inexperienced with foldable props, I have absolutely no clue. From what I could gather, foldable props are supposed to move freely and some magic occurs to keep them extending outward and providing the lift forces needed.

I'm sure I must have done something wrong, I just don't know what it was and it's bugging me. :)
 

sledge57

Member
I haven't flown DJI in a while, what is the led supposed to show when you have good Sat lock? Maybe something, motor, esc, .... who knows just failed at that time. Most electronic equipment seems to fail early on or last a long time (barring crashes). Could have been something defective... also thoroughly check all wiring, bad solder joint could fail after a few minutes also.

Good Luck.
 

hangloose

Member
I just found a problem with my configuration, I had the A2 configured for Octo instead of Hex. It was just something that I overlooked apparently. I have no idea how the thing flew as good as it did with the wrong configuration.
 


Benjamin Kenobi

Easy? You call that easy?
I just found a problem with my configuration, I had the A2 configured for Octo instead of Hex. It was just something that I overlooked apparently. I have no idea how the thing flew as good as it did with the wrong configuration.

Glad you fixed it! It's so easy to overlook little things in the assistant program. Have fun flying! :)
 

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