Kosmik 200 Burn down...Diabolo

[rdavis]

Any update on how K is handling this?

[snipealot]

Originally Posted by rdavis

Any update on how K is handling this?

I sent the toasted esc and motor to Kontronik USA last week, so far I have received a replacement Kosmik 200hv from Germany but still no word on the motor.


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[xioxia]

I sent the toasted esc and motor to Kontronik USA last week, so far I have received a replacement Kosmik 200hv from Germany but still no word on the motor.

Anything new?

[snipealot]

Still waiting. No word on the root cause of the esc failure or receipt of a motor.

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[NevErSn0w]

Sorry for your loss man!
I know I resurrecting a thread but im really curious on what the outcome was?

[Mercuriell]

Yes I'm curious for any news too! Just caught up with this thread. Certainly looks like an internal short of the power input. Fuse wouldn't have helped in this instance IMHO and even with a backup cell most of the smoke/fire damage would still have occurred. If the BEC got blown then it could have shorted out the flight electronics bus so a backup lipo may still not have saved the day. Still much higher risk of totaling the heli from dumb thumbs than Kosmik,failure so it's not gonna put me off the Big K!

[BKF]

Originally Posted by Mercuriell

Certainly looks like an internal short of the power input. Fuse wouldn't have helped in this instance IMHO and even with a backup cell most of the smoke/fire damage would still have occurred.

In my opinion, while the fuse wouldn't have stopped whatever it was that caused the internal short, it might have minimized the extra damage.

Once the short happened, the resistance would have shot up, driving the amps quite high. This would have blown the fuse and possibly saved the insides from getting so hot that they started to burn/melt.

It's really no different than what a breaker panel or GFI outlet does in a home. If a short occurs in a device, the resistance/amps start to climb, all the way back to the source of electricity. In a house, the GFI or breaker panel cuts off the source of electricity from the device, to protect it. If there was no such protection (like a fuse or breaker), the short continues, sometimes to the point of fire.

I wonder, though, if a short like this could cause a failure in the BEC circuit, causing a secondary short. This would suck if you had a 2s lipo buffer pack that kicked in, and fed back into the BEC leads on the ESC (which was shorted), causing the buffer pack to catch fire (because I don't know of too many people who fuse a Lipo pack).

[HeliFX]

maybe the motor had a short !

Pyro motor have been know to have the copper wire compromised from the manufacture.

[Wh1teAfr1can]

Originally Posted by HeliFX

maybe the motor had a short !

Pyro motor have been know to have the copper wire compromised from the manufacture.

motor shorts cause shut downs not burning up generally. At least on Kontronik Esc's this is the case.

[HeliFX]

well i would have to dis-agree .

lets just say I wouldn't want to run a motor with compromised copper wires.

could be a older firmware as stolla pointed out.

[Wh1teAfr1can]

Originally Posted by HeliFX

well i would have to dis-agree .

lets just say I wouldn't want to run a motor with compromised copper wires.

could be a older firmware as stolla pointed out.

The motor has been evaluated and to my knowledge there was no issue with it.

[HeliFX]

if the motor was just visually inspected from the outside then that's not enough.

when we rewinded pyro motors we discovered some really bad tears once removing the old wires.

Its difficult to find a short with megger tester once the motor has been terminated or requires a really expensive version.

[Wh1teAfr1can]

Originally Posted by HeliFX

if the motor was just visually inspected from the outside then that's not enough.

when we rewinded pyro motors we discovered some really bad tears once removing the old wires.

Its difficult to find a short with megger tester once the motor has been terminated or requires a really expensive version.

I would imagine after resin coated wire is bent through an extreme angle around a motor it would tend to tear the insulation as it is removed.

[HeliFX]

nope would have to dis-agree once again.

original windings on all pyro motor had no added epoxy resin coating.
those tears they where experience may have been cause by the rewinding machines.
P700 where not an issue due to the O.D. size wire used however the larger O.D. wire which are used on the larger motors are more difficult for the automated machines.

[Wh1teAfr1can]

Originally Posted by HeliFX

nope would have to dis-agree once again.

original windings on all pyro motor had no added epoxy resin coating.
those tears they where experience may have been cause by the rewinding machines.
P700 where not an issue due to the O.D. size wire used however the larger O.D. wire which are used on the larger motors are more difficult for the automated machines.

I meant the enamel insulation on the individual wires themselves.

[HeliFX]

the protective coating on most magnet wire is pretty durable so "no" extreme bending does crack nor tear that layer.
The stator itself also has either a protective epoxy coating or as in the case of scorpion motors nomex paper.

only when its push against a sharp object can it cut into that layer.

I'm sure K does not sit there and rewind each motor by hand. They have automated machine which can potentially cause nicks and scratches on the polymide coating