Internal Motor Issue

[birdracer99]

I have a HW EzRun 4274 2200kv motor that I was using in my limitless. I ran over some uneven road and it flipped and rolled. Not too much damage overall, but the motor stopped working.

When I run it, it sort of cogs a bit and then dies. After opening up I found a bunch of silver dust inside and some wires that came apart. Does anyone know how to fix? Is it as simple as soldering these wires back together?

Stock BLX185 2050kv for reference:

 

[DoNoHarm]

Yeah that’s exactly how you’d repair something like that, but the big question is IF you can get that joint back together. In my opinion that deserves a warranty replacement because of a brittle connection. That should never happen.

 

[LibertyMKiii]

This thing is probably done....
The wires are enamel coated and will not take solder. You would have to do the following steps:
1. scrape each wire strand to reveal the copper wire
2. solder
3. re-enamel the wires or other insulation so that they cannot contact other phases of the windings.

+1 on warranty claim or paper weight

 

[DoNoHarm]

This thing is probably done....
The wires are enamel coated and will not take solder. You would have to do the following steps:
1. scrape each wire strand to reveal the copper wire
2. solder
3. re-enamel the wires or other insulation so that they cannot contact other phases of the windings.

+1 on warranty claim or paper weight

One thing I was thinking of with the enamel coating, should he scrape it off? My thought process was, if he can get both ends hot and apply solder, it’ll stay in the broken part of the wire and not try to travel around and short circuit, because everywhere else is enamel coated.

 

[jkflow]

No, the enamel coating needs to stay where it is, the soldered items need to be re-soldered at the exposed ends. The coating was removed during assembly. You can burn it off with a torch but that stuff should easily take ~ 600F.
You do not have the tools or capability (no offense!) to do this correct. You would need high temp solder if you do try and attempt it. Most likely you will generate a short and fry your ESC. That motor is toast imho.

Again, in my opinion, motor overheated/over-stressed and the solder disintegrated, bad solder-joint wouldn't leave 'little flakes' everywhere, that is a telltale sign of heat. Most likely, the last impact did the trick but this motor was on its way out prior to that run.
This heat might not even be noticeable outside, as it is most likely due to short burst and high amps. Granted, could have had an underlying manufacturing defect from the get go, this is very uncommon.
I did manage to do this once on a motor and that was clearly due to overheating. In that case the wires were crimped and soldered, the crimp held fine and the solder flew everywhere.

 

[LibertyMKiii]

One thing I was thinking of with the enamel coating, should he scrape it off? My thought process was, if he can get both ends hot and apply solder, it’ll stay in the broken part of the wire and not try to travel around and short circuit, because everywhere else is enamel coated.

I just doubt in the confined space you can do it at all.
as @jkflow noted the risk of having a short and damaging the ESC is high. It is just not worth the risks.

I have removed enamel coating with a chemical process and soldered the wires. Nothing about that process was fun ?
I may have shortened my life by 5 years with those fumes.

 

[jkflow]

I used to deal with that coating when I was winding transformers in my younger days Controlled heat works the best but you can't just burn the heck out of it or you weaken the copper. At any rate, not recommended if you don't have sufficient room to work with. You could always scrape it off with a knife.

At any rate none, of that is needed in the above issue as the soldered tips are already clean.