Spintend ubox single on fire

I recently finished a balance board build. Its a blast! What a fun thing to ride.

Yesterday after about 100km riding total I decided to take it to the trails.
Unfortunately It went from this:

To this:

Real quick. Some fire and some popping, but luckliy the kit is well packaged in aluminium and nothing outside really got damaged. Here is the autopsy. It looks to me like a cold solder that came loose when I took it out on the bumpy forest trail. What do you guys think?

Just curious, is the casing metal or plastic?

1 Like

Its anodized aluminum

1 Like

what firmware was you using?

1 Like

5.3 stable.
Spintend tested it with the motor before shipping

Edit: phrasing

They are really living on the edge putting the positive lead that close to the aluminum case


Yes that is also true!

I wonder if the PCB sandwich idea isn’t as reliable as first thought.

I feel like there is some chance that some of those header pins lost connection at least briefly while under vibration.


Its a pretty solid unit when bolted. Do you think a bad pin connection would cause this?
I bonked in to a rock real slow when it bursted in to flames

Hard to speculate with little info and without the actual unit or having experienced the failure personally.

However, this makes me feel stronger about the theory already stated.

Could also be that positive lead popping off was the cause and not the effect of the failure. Hard to say.

That’s what my first thought was


1 Like

Post more high-res photos from all angles.

Also of the positive wire solder.

Thanks for the suggestions.
These are the only pics I have now.

1 Like

Looks more like the positive terminal desoldered itself after touching the aluminium casing. Are there burn marks or molten metal on the case were the positive main lead was attached? Looks a bit like it.


Looks more to me like the positive lead popped off and touched that bar down closer to the phase wires, but I can’t imagine how it would have been installed to cause that to happen.

But I don’t have enough information to say anything for sure.

I feel like the positive lead popping off might be an effect and not cause. IDK

Very sus that the pad under the positive lead has no solder left on it. Or does it? Not enough information.

Yes it sure does. Also on the other side near the negative as previously pointed out

1 Like

This, in my opinion, is just where (possibly magic) smoke escaped around the USB port connector.

My bet is on touching the side wall. @Jarn demand your money back.

1 Like

50% chance it may still work. Clean it up with some isopropyl and a toothbrush, resolder and test with a lab bench power supply limited to like 5-10A


Time to find out if the smoke was magical or just regular smoke