Uncontrollable Auto-ascension By S800: How Do I Stop It?

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AerialDiesel

Member
Hey all, first post here, and really hoping you can help with this issue. I'm hoping it's not a common one as I don't want to look moronic, but at the same time we've been researching an answer but to no avail.

We have a couple DJI S800s. The one you'll see in the video has had the issue of auto-correcting itself when in slightly windy conditions. It will suddenly ascend, climbing even today as high as an estimated 150 feet, without any throttle control by the pilot. Try landing it when this happens! This S800 has been plagued by this for some time now, and while we've tried every gain setting and played with them, nothing seems to help.

It will happen in either GPS or Attitude mode. While I'll admit it's a nice safety element to keep from drifting or crashing, it's a bit too dramatic for the copter to be of any use. Anyone else experience this? What obvious button haven't we pushed to correct this?

EDIT: Here's another try at the video. First one wasn't working right: http://youtu.be/dabgbitltKA

Thank you in advance!

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T

Tahoe Ed

Active Member
What FC are you using? What are your gains? is the S800 stock? What is your AUW? Sorry for the questions, just trying t get a feel for your issues.
 

A

AerialDiesel

Member
No, great questions! Thanks!

FC is Wookong M.

Pitch 210
Roll 210
Yaw 173
Vertical 173 (we've been adjusting this to figure out what's up, to the top, to the bottom)

I'm pretty sure it's stock (we have another guy building them for us).

The UAW is 11.5 lbs.
 



gtranquilla

gtranquilla

RadioActive
I had similar but much more severe altitude control issues with a Naza on a modified F550...... turned out to be a motor/prop vibe issue affecting the IMU sensors (not just the baro).
I tried rebalancing motors and props then finally mounted the FC as well as the RC receiver on Kyosho Zeal tape and all the problems disappeared!
 


A

AerialDiesel

Member
No flight log. What we're thinking is that the IMU is bad. We used the isolation tape method in some gel to the same result. This IMU was from a crashed S800, though not so bad that we thought it could've damaged the IMU. We have a new IMU and will try that. Can IMUs get damaged to this point without being hit directly?
 

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