F550 WKM went down like a sack of bricks!!!

This is SOOO great! Thank you to all of you for your reply and suggestion. It makes a lot of sense. I had pinpointed the ESC as possible/plausible source of problem but the specific problematic was unknown, until you guy got involved with this thread. Your implication is greatly appreciated!!!!! I will report after mods.
 


Did you get any results yet? Does it fly any better? Twitch Free?

KS

This is SOOO great! Thank you to all of you for your reply and suggestion. It makes a lot of sense. I had pinpointed the ESC as possible/plausible source of problem but the specific problematic was unknown, until you guy got involved with this thread. Your implication is greatly appreciated!!!!! I will report after mods.
 

EUREKA!!!!!!

I have talen drastic measures to isolate the possible intermittent connections caused by the easily rotating contact element of the 9212 motor connectors to the ESC. I CUT THEM OFF AND SOLDERED THE WIRE DIRECTLY TO THE ESC CONNECTOR !!! It is not has difficult as it initially seems, you need a fresh X-Acto blade however to cut off the heat shrink and not the wires. As the ESC connector is hollow and capped at one end, the soldering is very easy. I replace the heat shrink with new one (Don't forget the install on wire BEFORE you solder...). I don't want to be overexcited as I only have 3 X 10 mins flights with the F450 so far BUT, ABSOLUTELY NO GLITCHES, STEADY AS A BAR, IT SEEM TO FLY HAPPY AND SMOOTHLY, JUST AS IF I JUST GREASED THE BEARINGS AFTER FLYING A WEEK WITH DRY BEARINGS (figure of speach of course...). Looks very promising, I continue the testing with an increasing smile!!!!!!

Will report progress again after a dozen more flights!
 



As this turns out, if this allows all DJI F450 and F550 to fly RELIABLY without any system glitches which has cost me over $300 so far, I think it is a good reason to scream don't you? :)
 


I sure did.. :) I ended up with 2 f550 frame, 2 WKM system, 2 Futaba 8fg trying to isolate the bad component out.. not all the reason..but that is what I told the wife...
 

Another 15 min + flight in gusted winds up tp 12 mph and she was FLAWLESS! I am using an hyperion 5000 mAh that loads her up pretty good and the variation in wind direction and velocity allowed me to see and hear the amazing NAZA controller in action. The hole flight in this condition of wind remained within8 feet horizontally and 3 feet vertically. Off course, the box is much smaller in near no wind conditions. I believe this is it!!!!! Off course I will happily conduct more flights but I have a good feeling about this one!!! It is great to fly and to be able to rely on your equipment. If I screw up, I pay and I can easily live with that, but if the ship is in a GPS hover for 30 secs and violently flip inverted, without control input, that really p...... me off!

Hoping and believing this will make a lot of pilots happy!
 

DLien

Member
I want to make sure I understand what this fix is.
Are you re-soldering the motor wires into the existing connectors to ESC’s? Or are you soldering the motor wires (without the connectors) directly into the ESC's?
 

Good question indeed. In order to absolutely take the intermittent connector issue out of the equation, I have unsolder the motor wire going to the motor connector leaving the end of the wire bare. I them solder the wire directly in the DJI OPTO electronic speed control (ESC) female receptacle. This way, there is NO possibility of intermittent contact.

Off course, one might say that this becomes a permanent connection and therefore does not allow for a quick motor disconnect, so be it! I don't disconnect my motors very often... If I ever need to replace a motor, I will simply pull out the soldering iron and unsolder the 3 wires to remove the motor. In my opinion, this is a pretty low price to pay for peace of mind flying.... Additionnaly, the ESC female connectors are very thin and allow for super easy soldering of the wire inside it, once you have remove the heat shrink around the connector. It is not necessary, nor recommanded to remove the heat shrink around the ESC. It contains many components that must be precisely fitted in order to work properly. I know, I had to see what's inside and got a little hot on the forehead putting it back together with a new huge heat shrink.... ;)

Try this, you will be happy!
 
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DLien

Member
Just as a follow up to the crash I reported on this thread. I was caused by a bad motor. I ended up swapping out motor #6 on the 550 and it has been performing very well since.
 

papawg

Member
I had a similiar thing happen to me with my DJI F550. Mine fell like a brick from 200+ feet. Needless to say, my worst crash to date.
I also broke two arms, some props, etc. I got it all put back together but I've had a vibration issue ever since and yesterday it flipped on me at about 3 feet above the ground, broke a prop and left me wondering, what is going on. I'm thinking maybe the ESC cut out for a split second so I ordered one for troubleshooting. Does anybody know how to troubleshoot an ESC
other than change it out?

I should have read the posts a little closer before I posted this. The intermittent ESC connection could be my problem too. Worth checking out. Thanks.
 
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Dewster

Member
This is interesting. Eliminating as many possibilities as conceivably possible to prevent crashes is what we should all do. I do like the plug and play aspect of DJI. It makes for quick builds. I found that the bullet connectors were tight on my builds. Soldering the connections just eliminates that dark cloud feeling of what if one rotates or comes disconnected during flight. Props seem to be the biggest issue of these aircraft falling from the sky. I read on this forum that some of DJI's motors lock up during flight.
 

DesJardins

Member
My concern email was unanswered by DJI, my suggestion is to buy a quality motor and not look back. You don't want to deal with flipping like I have over the last month. Haven't been able to toss FPV gear on from the lack of trust it won't fall out of the sky on me.
 

papawg

Member
I have flown my F550 twice since I did the solder job on the bullets, which upon close examination I could tell two out of the three were quite loose, I have started to gain a little confidence in the thing staying in the air, however I think I will stick to taking pictures with my GoPro for a good while before I mount the new Sony fx100 that I recently bought. What a nightmare that would be, how could I explain it to a wife who already can't believe I spent that kinda money on something that may be destroyed in a couple of minutes. Another thing that I found was the vibration issue I was having with the F550 went away for the most part after I reduced the gains to 100 (default). I also altered the camera mount to where it is completely isolated from the frame of the Hexa by using foam insulation. The only thing left to do is fly more and regain that confidence in the machine.
 

kloner

Aerial DP
man, you get minutes out of good expensive stuff... i've seen it go in seconds......

this is how kloner makes his stuff work, aside from making absolute sure the solder joints are good, this little spring thing gets loose and from time to time needs adjusting, i do mine like this
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deans plugs need the save lovin
 


papawg

Member
Kloner, that looks like good advise about bending the springy thing out to make it tight again especially with the deans, but I still think it would be better to solder the wires to the ESC. Probably just me.
 

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