Why would one motor and esc lead unsolder themselves?

[Hot Rodney]

Why would one motor and esc lead unsolder themselves? I am running a neu 1527 with a seaking 300 pro plus esc and both the esc and motor unsoldered themselves. the 8mm bullets were still together. I'm running it on 6s. Motor and esc do not overheat. The leads are short but the connection was tight. I'm baffled!

[Fluid]

Most likely a poor soldering job leading to excess resistance. While most folks never check, the wires and connectors can get very hot.



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[fweasel]

Bad solder joint is the most likely suspect, but a poor fit between the two bullet halves can also cause extremely high resistance and heat.

[RaceMechaniX]

A 1527 can pull a lot current which heats the connectors. Several possible causes and fixes.
A loose connection between the male and female connectors will lead to heating and unsoldering of the terminals. Use a pair of needle nose or something like a conical body reamer to gently open the male side fingers up. This will add more spring tension and reduce the self heating of the connectors.
A large gap between the wire diameter and the solder cup on the connector will also lead to increased resistance and self heating which results in solder flow. Try building up the wire diameter by taking solid core copper hook up wire and wrap it around the magnet wire coming from the motor or ESC. This builds up the wire diameter making the solder gap smaller. "Hook up" wire is commonly available from electronics supply houses in a variety of wire diameters. I bought about 8 different sizes to be able to build up motor wires to fit snugly into 8mm bullets.

[fweasel]

Try building up the wire diameter by taking solid core copper hook up wire and wrap it around the magnet wire coming from the motor or ESC. This builds up the wire diameter making the solder gap smaller. "Hook up" wire is commonly available from electronics supply houses in a variety of wire diameters. I bought about 8 different sizes to be able to build up motor wires to fit snugly into 8mm bullets.

That's a great tip, melting connector issue aside. Approximately what gauge wire are you using? I have access to scrap cat5 and cat6 solid copper wire from work which is 24-22awg, but unsure if that would be too thin and unnecessarily complex for this task.

[Hot Rodney]

Great Tip. The cups were completely filled with solder, but I didn't use any other filler. I'll give it a try. If you look at the picture, the bullet connectors are still tightly connected.

[ray schrauwen]

A 1527 can pull a lot current which heats the connectors. Several possible causes and fixes.
A loose connection between the male and female connectors will lead to heating and unsoldering of the terminals. Use a pair of needle nose or something like a conical body reamer to gently open the male side fingers up. This will add more spring tension and reduce the self heating of the connectors.
A large gap between the wire diameter and the solder cup on the connector will also lead to increased resistance and self heating which results in solder flow. Try building up the wire diameter by taking solid core copper hook up wire and wrap it around the magnet wire coming from the motor or ESC. This builds up the wire diameter making the solder gap smaller. "Hook up" wire is commonly available from electronics supply houses in a variety of wire diameters. I bought about 8 different sizes to be able to build up motor wires to fit snugly into 8mm bullets.

I learned this from you and maybe Ken Haines. Ken mentioned using a smaller, say 5.5mm or 6mm female connector (cut shorter) to solder into the large inner 8mm cup and then you would have a smaller cup to solder into and much more mass to dissipate heat too. I remove the majority of of a female 6mm front skirt to go into an 8mm connector so there is no extra length.

I found some old copper solder tips I put on my lathe to make reducers as well as using modified 6mm females.

[fweasel]

Oh, now my mind is spinning Love the idea of using my lathe and smaller bullets.