DJI S800 issues with arm to core connection - please be aware !

[atomkind]

This is a problem that will sooner or later lead to an esc failure in flight.

When in the middle of flying my s800 suddenly nicked about 45 degrees to one side, recovered and repeated this for several times i was kind of shocked. I managed to land but ripped the whole copter apart on search for the failure.


I recognized that the esc on arm 4 beeped when i lifted the copter at random times.


After changing the esc, resoldering every single solder joint on the way from the controller to the esc the problem of the beeping arm did not go away.


Finally I discovered that the connection between the arm and the core itself is the issue and softened over time.


As the copter is 13 months old and got every update (from evo arms to evo dampening). Surely it has 200 flights without issues but this problem seems not to be a repairable one. You can clearly see sparks between the arm and core poles paired with occuring bad esc status. So this s800 will not fly again.


I will now forward this issue to DJI and my retailer to see if I get replacement.


Please be aware of this issue as it might occur on every s800 out there thats used for a longer period of time.

Please find the video here:

http://www.youtube.com/watch?v=L5qlWCvE_lg&feature=youtu.be

 

[Louis O'Dwyer]

Just replace the connector unit on the "core" ?

 

[atomkind]

As I have this issue on 2 arms I think it will happen on even more. I´ve removed the connector blocks from the main core and noticed that the springs on the contacts got bent all the way in over time. This and the fact that the whole frame weakens its structural integrity leads to contact losses between core and arm.

I would have to replace all the 6 connector blocks to fly 12 months and then change them again. Not a perfect solution. Maybe I change over to a carbon copter frame.

Also I think this might not be an issue on s800 without damper kit. Without the dampening kit the h-bar gives the frame more stability as it connects the 6 arms together. With the damper kit installed this very connection gets lost by the dampening system itself which accelerates the weakening of the arm-core connectors.

No respond from DJI so far.

Greetings

 

[ProPilotWannaBe]

Also I think this might not be an issue on s800 without damper kit. Without the dampening kit the h-bar gives the frame more stability as it connects the 6 arms together. With the damper kit installed this very connection gets lost by the dampening system itself which accelerates the weakening of the arm-core connectors.

It looks like I may have a similar problem as you, but I do have the damper kit installed. Last week on two ocassions I could hear arcing coming from inside my M3 connection. However, once I took the arm off and back on, that went away and I seem to be flying OK. However, it does have me on edge, obviously, and wanting to ensure it doesn't repeat itself again.

 

[atomkind]

I have the s800 EVO damper kit on it too.

I just ordered one of these connection blocks to see if it helps. I´ll let you know.

 

[jrlederer]

Sorry for sounding naive on this subject,but it interests me because I just finished building my new Evo S800 with all the perks like Zenmuse, iosd mark ii, etc. and I just wondering what you mean by you just bought one of those connection blocks? What and where to obtain these.. Also, are there any aftermarket upgrades worth purchasing to make this fly the best it possibly can? Lastly, I ended up relocating my ImU to the landing gear mount point, but it seems to me that this totally negates the ease of breaking this unit downforce transportation purposes. Anyone still have their IMU inthe original recommended position and are happy with overall performance?

thanks,in advance, for your time and help with these questions.

Have a nice day

Jonathan.

 

[ProPilotWannaBe]

Sorry for sounding naive on this subject,but it interests me because I just finished building my new Evo S800 with all the perks like Zenmuse, iosd mark ii, etc. and I just wondering what you mean by you just bought one of those connection blocks? What and where to obtain these.. Also, are there any aftermarket upgrades worth purchasing to make this fly the best it possibly can? Lastly, I ended up relocating my ImU to the landing gear mount point, but it seems to me that this totally negates the ease of breaking this unit downforce transportation purposes. Anyone still have their IMU inthe original recommended position and are happy with overall performance?

Hey Jonathan. They questions you asked are quite broad and I hope some others might chime in with their thoughts. In particular, the question about "upgrades" is something that you will get a thousand different opinions on. I personally do not have any third party upgrades. I only have the DJI main equipment and the upgrades they recommended (such as the IMU mount on the landing gear frame).

The "connection blocks" we're talking about are those six "U" shaped mounting points for each of the arms on to the main "hub". These can be replaced, through they are a pain to do so. The connection we're talking about that apparantly get worn out are the connections in those blocks to the arm connectors. This post is the first I have heard of that issue, though, as stated above, I did experience my first indication last week that something wasn't quite right.

As for the IMU and transportation, I travel with my S800 and I have the IMU on that tray. I'm not super happy with my solution, but basically I mounted the flight computer on top of the S800, and I simply unplug the IMU cable from it when taking it apart. I have toyed with the idea of not fixing my IMU on the tray permanently, but rather strapping it down with zip ties or velcro so that I can remove it from the tray. When I get a chance, I might start a thread on this forum asking that question of others.
FYI, I did have my IMU in the original position, and I was happy with it, but decided just not to risk it, so I moved it to the anti-vib mount.

 

[Louis O'Dwyer]

Sorry for sounding naive on this subject,but it interests me because I just finished building my new Evo S800 with all the perks like Zenmuse, iosd mark ii, etc. and I just wondering what you mean by you just bought one of those connection blocks? What and where to obtain these.. Also, are there any aftermarket upgrades worth purchasing to make this fly the best it possibly can? Lastly, I ended up relocating my ImU to the landing gear mount point, but it seems to me that this totally negates the ease of breaking this unit downforce transportation purposes. Anyone still have their IMU inthe original recommended position and are happy with overall performance?

thanks,in advance, for your time and help with these questions.

Have a nice day

Jonathan.

Here's how I pack mine away:
http://youtu.be/mW19jpU_NPY

 

[Ramhvac]

I like yourself have a fully upgraded S800 with all of the EVO parts, I have had several hundred perfect flights, I regularly fly upto 1/2 mile out over the ocean, with no problems. Then this last week on a shoot with actors below, the craft starts twitching, then a dip, then complete motor failure, I regained the craft but it was spinning, so I land, I think no big deal, I change to a spare arm and motor. Then off the the bay for another shoot, during the next 3 flights there were weird things happening, and my confidence in the craft was diminishing. The last shoot of the day was to follow alongside a New Porshe convertible as it drove up the winding drive lined with trees. On the third take another motor/esc failure putting it in a hard spin, on landing the retract gear snagged ground cover and broke in total 2 pieces of carbon on the gear. I finished the shot with a 680 sized craft with Zen 3d/Gopro, it came out great.
Once back home I dissected the craft, to find (3) bad female arm connectors under the top plate. I replaced 2 waiting on more connectors to come. To me vibration and the constant assembly/disassembly make this type of connector unacceptable. I have now retired the craft, and started using the S1000. The S1000 and new S900 have permanent arm connections that are always attached, so this problem solved.
In conclusion: if you fly this craft long enough you will have this failure, the more weight and vibration the sooner it will happen.