Naza GPS flipped but why

[Omegamanuk]

I'm new to quad copters, we have just got a 450 flying with the naza GPS installed, had about 5 or6 fights on it now all Los, but added a 200mw and viewing through a gopro3, and on the second flight it flipped for no apparent reason , the gopro was recording and the footage is below, I'm thinking from the audio a motor stopped, but at home they all spun up ok, must admit I'm puzzled.

http://m.youtube.com/#/watch?v=mYptQS8odAk

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[pk-surfing]

I you are using the DJI motors connected to the 30A DJI ESC's then you will have this happen again and again until you desolder the the bullets from the motor leads and solder them direct to the ESC.

Not a nice job to do but the supplied bullet connector male/female pair just do not give a good electrical connection, they might appear tight but in fact the 'squashable' slotted cage part of the male bullet does not squash enough to give good electrical continuity, I have 12 pairs in front to me that I removed and when plugged together you can easily spin the main part of the male bullet when it is in the female barrel.

Have a look here....

http://fpvuk.blogspot.co.uk/

Do this mod and your problems will be over.  :)

PK

[DaveyLC]

The bullet connectors in principal are fine.. ive never heard of the connection between them being an issue before??

the weak point in 'some cases' has been the soldering on the motor bullets.

Personally I've never had a problem and my F450 gets abused :D but others have reported issues and shown photos of the bad joints.

[pk-surfing]

DaveyLC,

PM me your address and I'll post down a pair of the DJI connectors I've removed so you can see what I mean.

With the bullets unsoldered and then plugged into each other the solid centre core of the male spins round inside the springy 'cage' that's on it, there intermittent connection clear and simple.

I've used the DJI ESC's on another F550 but used iPower motors with their long leads and bullets, these fit the DJI ESC bullets fine and no slack or intermittent connection.

I've kept the ones I removed so that I can show them to Coyote and Dakarsg next time we fly.

PK

[DaveyLC]

Give them a squeeze with some snipe nose pliers then.. Changing arms would be an arsehole of a job with no bullets!

[g.collins]

I Have always soldered my motor leads directly without connectors, then heat shrink them, why take the risk, it doesn't take that long, the p;rice of my quads is worth it.
:) G

[Omegamanuk]

Thanks for the replies,

I'm not using the dji esc s but am wondering if that's where the problem lies . All connectors in the photos are pushed in as far as they will go, yet some go in further than others, (this may be due to excess solder stopping the plastic covers going down far enough) think I will put a spot of hot glue on them to stop them working out.  I'm also going to put some black tape on the side of the naza as a precaution.

Then test and see if it flips again!

Thanks guys.




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[Omegamanuk]

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[Dizzy]

My tips of the day, after many many years flying models if it can go wrong it will go wrong at some point  :)

1/ I dont use servo extentions becouse your introducing another fault point. ( remake to length or solder your extention)

2/ I always solder important connections by wire wrapping mechanically first then soldering

3/ don,t use a switch unless its a really really needed. if you do make sure the (switch on position is facing forward if its a slide switch)  I have seen models that (could) have been saved after a mid air crash becouse the impact switched the radio off ;D

4/ remember that the more friction joints in a circuit the more likily it is to have issues when vibs occour whilst flying :) which is a case in point on this thread  :D

dizzy :)

[Zeeflyboy]

1/ I dont use servo extentions becouse your introducing another fault point. ( remake to length or solder your extention)

Agreed, but sometimes a servo extension is the best solution - just put a little heatshrink over the joint or use a servo extension lock like these http://www.electricwingman.com/servo-extension-lead-locks.aspx

3/ don,t use a switch unless its a really really needed. if you do make sure the (switch on position is facing forward if its a slide switch)  I have seen models that (could) have been saved after a mid air crash becouse the impact switched the radio off ;D

Best to go for a "fail on" switch if you really need one. If anything goes wrong with the switch, power stays running... Good tip about the installation direction.


To the OP, check the solder joints in the bullets themselves too - it's not been unknown for issues to occur due to a cold solder joint.

[c0nners]

+1 for blaming the bullets to the ESC. I had random flips that came after several minutes of flight. I went for a direct solder into the ESCs and I haven't had a glitch since.

Good luck fella.. Sort it before you break something!
Conners

[DaveyLC]

OP: Check your motor bullets if you're using the DJI motors.. Remove the heat-shrink and see how much solder you've actually got in the bullets, DJI's factory have been known to be a bit "stingey".

[Omegamanuk]

Went out with it tonight, flew the first battery fine but on the second it started twitching so brought it down to a few feet off the grass, the left rear motor seems to be the problem as it was dropping on that corner, then it flipped again . Going to have a good look at the connections on that corner tomorrow and maybe stress test on the turn table.


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[Omegamanuk]

Well finally realised my mistake, I had read somewhere that you should cut 3 of 4 of the bec red wires going to the naza unit, the esc that went down was the one feeding the naza unit. It now appears the naza has a bec already and you cut all 4 red wires from the turngy plusher becs. Oh we'll you live and learn.

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[DaveyLC]

Yeah only one ESC should be supplying 5v..  You're lucky you didn't get the magic blue smoke :D

The fear-monger'ers can go back into their caves now and return to throwing darts at photos of Spektrum products.  :P