wire breakage

[simhatus]

Hi

Had a problem with my quad one of the motor wires broke just behind where it comes out of the bullet connector. my quad flipped twice before landing the right way up without damage.

This is of course no problem to repair, although i';m slightly concerned that there are 23 similar joints that may fail.

Has anyone else experienced this type of failure and what should i do to prevent this happening?

The props are balanced and the connections tie wrapped, although as i';m typing this it occurs that a piece of foam between the arm and the bullet connectors may be a good idea.

Simon

[Biffa]

A join of any sort will be a weak link in any power system.

I have never had a bullet connector fail or a wire snap like that so maybe you had a manufacturing defect or that wire was previously stressed at that point?

The only real way to eliminate failures is to remove the points that can fail, like solder direct from ESC to motor. Bit of a pain as stripping down afterwards is more involved but maybe worth doing for peace of mind. I will certainly be doing this on my FPV build.

[SimonS]

What motors do you have?  DJI are known for their crap soldering on the  bullets.

[simhatus]

Hi

The solder joint didn';t fail the wire did and i put the bullet connectors on anyway. The motors are rc timer.

They may have been stressed a bit as the quad has met the ground more rapidly than it should a few times, but whilst learning to fly one thats likely to happen. I';m Thinking you may be right biffa to solder it direct although that does make repairs more difficult.

simon

[fruitsalad]

what i do is,remove an inch of the sleeving carefully(reuse it later) flow solder down length of exposed wire,replace sleeving(fiddly but doable),cover with heatshrink,dont shrink it down yet,solder on the bullets,then shrink the heatshrink down.
no more snapping of wires behind the bullets..

[simhatus]

Hi

so your heat shrink is quite long and goes beyond the tinned part?

Simon

[fruitsalad]

yes the heatshrink i use goes from back of bullet to over the part you removed to solder

[simhatus]

Hi

I';ll try that then, thanks.

Simon

[simhatus]

Hi

Was going to use fruit salads method which i';m suere would be fine, when i noticed the wires from my hexcopter which has the same motors just with the longer lead has a multi strand silicon wire which at some point it must change to from the 3 strands of copper wire that come off the motor.

As i had cut the hexcopter wires down and put different bullet connectors on i still had the remaining wire with the origonal bullet connectors so used the last inch or so of those and attached to the shortened quadcopter motor leads.

Simon