Repair X12 Motor

[B&H Racing]

I`ve got a Nosram X12 motor that I bought second hand.

As you can see by the pics it has got a tad hot during its life.

And the solder has melted.

Can this be repaired using high temp solder etc or am I wasting my time ???

[Hog]

Think your best bet for that Brett is as a paperweight

[muratti]

How hot must a motor get to melt the solder?

[B&H Racing]

I will probably eventually get around to getting another one.

So I would have some spare bits.

Originally Posted by Hog

Think your best bet for that Brett is as a paperweight

[DCM]

clean off the old solder and use a hot iron and resolder...

[B&H Racing]

DCM, I tried and it melted again.

Thats why I was thinking about using some high melting point solder.

The motor was running warm but not too stupid.

And someone is running the motor exactly same car gearing etc with no problems.

[DCM]

if it is melting the solder, then there is an issue somewhere.

[SlowOne]

Solder is a generic term for metal alloys that melt at a lower temperature than the metals they are joining. Solders can melt in a range of 90 to 450 degC, above that the process is called brazing.

IF the motor is soldered at this joint (it might be brazed) then the chances are that the solder used will contain silver, and its melt point will be well over lead solder (180degC) in the range 280 to 320degC. As usual, Wikipedia is your friend!!

Although the heat you measure on the outside of the motor is much lower - that is the surface from which heat is dissipated - it is generated inside the motor. If you get 60degC on the outside, it can be double that on the inside, and higher still at the joints where wires meet connectors. The other reason it might fail is that it wasn't fully wetted when built, the temp turns it soft, and the vibration fractures the joint. To repair it will require silver solder of the correct type, a high-temp iron (or small blowtorch) and a bit of skill.

Heat generation depends on speedo set-up and driving style as well as ratio. If you run drag brake, or use the brakes, it generates a lot more heat than if you don't. Many of the big differences in motor temps at the end of races are down to this. If you're a brake-jockey, you'll need to run lower ratios and less timing than those who can run without. These types of failures are more likely if you use brakes than if you don't, due to the momentarily higher temperatures the brakes generate, it isn't always a pointer to a manufacturing fault. HTH

[B&H Racing]

Good reply !!

I am thinking about brazing etc

We run 13.5 Stock motors inside on a polished wooden floor.

It isn`t the biggest hall so you are on and off the power all of the time.

The the best for motors.

The Novak 13.5 motor I ran previously on the same gearing did not seem to have a problem with it.

[simoncrabb]

I've successfully fixed similar with 'normal' solder, and a normal soldering iron.

It's nothing special, it's not going to take any more current than a regular solder wire on motor or speedo or battery etc.

They (X11, X12s) do melt though, and it's usually gearing... mine certainly was, well, it might have been running it for 10 minutes on gearing suitable for 6 or 7 minutes...

[dodgydiy]

silver solder needed there me thinks and some decent flux paste too. standard lead solder lasted about a minute on the comm of brushed motors and the can barely felt warm when it failed, you would be very surprised what temperatures those little conductors get up to.