Solder failure?

[Navherc130]

So what brand solder are folks using? I get a repeat failure on one pole and it is the same pole everytime. The motor lead to gold connector is the point of failure. Never on the ESC side of the connection. Do I need to go 5mm bullets between motor and ESC? Boat is a Motley, 440/3, HK 1900kv and 120 esc. Batts are Turnigy 5.0 2s's 40C each I think. Thanks.

[iop65]

because it is the same wire everytime i would clean that wire before soldering : the wires on the motor have some kind of coating on them
perhaps the coating isn't fully removed on that perticular wire

use some 400/600 grain paper and "clean" the last cm

i think the 4mm bullets on the motor are up to the job you are asking them to do, it's not a very hot setup

ps : you probably know this but don't use solderproducts that contains acid for electronics

[electric]

The 4mm should work. Everything posted above is correct. But, the 5mm are worth doing for sure. Also, have you got the wires from the motor to the ESC as short as possible? Something like two or three inches, just to keep the heat down as much as possible?

[jcald2000]

The motor wires have high temp varnish, solder pot or sand each strand of motor wire is the only thing that works.

[montymike]

Did u solder them on to the 4.0 connectors?

[Navherc130]

Wires are as short as possible given the stock MC arrangement. I will be sure to burn the old solder off and try to sand. What is a solder pot? I was connecting the bullets via torch, so I figured that would remove varnish. Thanks all, will report on results.

[montymike]

Get ur self a 60A soldering iron u will be glad u did Cspecially when you get into the bigger wires.
I have this setup in my revolt killer tried on 5s not on 6s .

[iridebikes247]

The torch should be more than hot enough. I've heard of this happening before if the motor wires are cut by one of us, after they've been already cut in the factory.

Me personally I would put acetone in a small dish, and bend the motor wires so that the tips rest in the liquid and let sit for 2 days, then torch again, use sand paper, torch one more time and solder up...lol. I don't think you'll have an issue after trying these methods all together.