Help!, s800 problem, any ideas?

ricardo

Member
Hi everybody,
Today I had this problem with my s800, it started suddenly. Once I could put it in ground one engine wasn't turning. This is the video when the problem start, the camera does not follow the nose because it was in free mode.

https://www.youtube.com/watch?v=8kqPXkJTDKE&feature=youtu.be

The second video is a short test I did after.

https://www.youtube.com/watch?v=_h5JON7mHAY

All engines seems to be running fine, but at the end you can see the problem again.
I have replaced the arm but nothing changed.

Any help is very welcome.

Thanks.

Ricardo.
 

Benjamin Kenobi

Easy? You call that easy?
Hmmm. I had a motor stop and start a month ago. For me the problem was the arm wasn't snuggly attached to the frame mount as it had become loose from carrying it around for 8 months. In my case I replaced the arm and the problem stopped.

Check the frame mount for the arm and that the contacts are clean and free of dirt. Check the receiver connections and those connections in the little red box where the flight controller connects to the frame.

Odd that replacing the arm didn't solve the problem. Means it's a frame/connection problem somewhere. Do you happen to have an iOSD with data logging? Data show anything?
 

ricardo

Member
thanks Ben,
I think I found the problem, it is related of what you mention. Thanks to the video my friend did, I noticed that the problem probably were in arms 1 or 4 (in slow motion you can appreciate in which direction is shaking).

This morning I replaced the arm 1 and everything seems fine, Just to be sure, I put again the suspected faulty arm and the problem has returned.
Anyway I'm going to inspect the points you mention

I'm not using osd so I don't have the data log

Nice reel you have!, are you using the Boscam diversity monitor?, I just brought one

Best,

Ric.
 


Benjamin Kenobi

Easy? You call that easy?
Hey,

Certainly got problems! Seems like a power connection problem with that arm. When you switched the arm the problem went away? If not then it's the arm mounting hub in the frame. You can hear the ESC rearming meaning the power is going off then on again. Try resoldering the connections and check the little pins inside are clean. You can bend the little connections inside a bit so they are more springy. What do you mean by 'small shaking'?

The second problem. I only saw you increase the throttle to less than 50%. The motors don't spin up fully until you are at 50% or above, unless you are in manual mode, it's a safety feature apparently.
 

ricardo

Member
Ben,
when I replaced the arm the engine/esc worked fine. But still the kopter did what I call "little shake" (please see this video, http://youtu.be/p2vQp0VZtgo )
DJI support told to try without the gps/compass but it is the same behavior, Maybe other arm/esc ?

The second problem is maybe not a problem, Usually the engine and throttle goes together, more power means more rpm.
but sometimes after engine start when I advance the throttle the engines first reduces the power (like in the video you saw), but when I reach more than 50%, the kopter takes off.

thanks
r.
 

Benjamin Kenobi

Easy? You call that easy?
The little shake isn't normal either. There's still something going on. Has your S800 been crashed at all? The little shake seems to be back to front so it could still be a problem with that front motor number 1. Have a really good look at that arm and connections. Test it on the bench and wiggle it around whilst powered up. Check the solder points also. Check the motor bearings also but unlikely to be this.
 

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