Why did this happen? MG29 + SK180 blow up w/ pic!

[MrEvoMan]

I'm trying to figure out why this happened and hopefully I can get some insight from the members here. The only thing I can think of is a manufacturing defect that finally came up now for some reason.

I have a Miss Geico 29 cat that I've pretty much replaced all the internals on. Specs are as of now:

1900kv 3674 motor
4S (2 - 2S in serial)
SeaKing 180A ESC
48mm cnc prop

I've run the boat at least 2 other outings (multiple packs) with no problems. Sure the motor gets warm, but usually temps are under 130. The ESC has NEVER gotten even warm to the touch. I knew the ESC was overkill for my setup, but I wanted to error on the safe side.

Today, I took it out. Made a slow lap around the lake at about 50% throttle. Came around for a pass and opened it up. Went top speed like normal for about 100ft and must have taken a bad wave and took a submarine trip. The entire boat speared underwater for a ways but since it's water tight it popped right back up. Of course, I left off the throttle even before it went underwater.

After it came back up, it studdered for a second and then started moving again. I was only giving it enough throttle to get it to move, no where near full. It went about 10feet and then POOF. The hatch popped up and tons of smoke. It was practically on fire.

I used my rescue boat and towed it back in only to find the ESC practically exploded.

Here's a pic:

ESCBlow_sm.jpg

Now, WHY would this just blow like that? With zero warning on a setup that's worked on multiple outings previously. The only thing I can put my finger on was some sort of defect of the ESC. No caps were puffed or anything prior to this. I'm lost and frustrated.

[blowNover]

First off wow! I accidentally (head up a$$) plugged two 6s packs into a t180 in series for a total of 12s it fried the t180 but didn't BLOW UP. Maybe the boat just smacked the water just right and the esc took too much of a slam? Maybe you didn't let off the throttle as soon as you thought and amp loaded the setup underwater? Or maybe it was just a ticking time bomb, no fault of your own. Maybe someone will have a better answer then I.

[MrEvoMan]

I was definitely off the throttle while it was underwater. I highly doubt any impact caused this - plus the ESC was glued down to the boat.

The fact it ran well a couple outings before this and was stone cold confuses me to why this happened in such dramatic fashion.

[blowNover]

I haven't a clue then to be honest. It may have just been a fluke. Maybe someone that's comes across this thread may have had the same problem? But I've never seen a t180 going out with that much of a bang.

[lenny]

Post more pictures of the whole setup and hardware to,
Do you have any video's of it running form before this happen ?

[Alexgar]

Hard to say I had a t180 on a cc2200 and after about 20 runs just quit working nothing dramatics just no more beeps or anything maybe a quality control issue

[MrEvoMan]

Unfortuntely no videos. Was doing about 50mph.

I've outlined most of the whole setup - not sure what else you'd like for info. Most of the hardware as in flex shaft, rudder, etc, is stock MG29. The things I listed are what's different from out of the box.

Here's the only other pic I have of the entire bay:

ESCBlow2_sm.jpg

[Fluid]

As with most budget ESCs, some will just fail. The T180s have been pretty reliable, but now that they have a good rep the original maker may be cutting corners. Sadly that is just the Chinese business model. Buy a new one and move on.



.

[lenny]

What were the temps with this setup on the motor, esc , cells, caps,
And also what was the pond temp that day ?
Say for a 3 minute run.

And what 2s cells were you using ? Name , Mah, C Rate ?

[MrEvoMan]

What were the temps with this setup on the motor, esc , cells, caps,
And also what was the pond temp that day ?
Say for a 3 minute run.

And what 2s cells were you using ? Name , Mah, C Rate ?

Motor really never went above about 130F. Esc was the Seaking 180a. I used 4S (2 - 2s in series). Caps were the stock, plus the additional as it comes from OFE.

Temp of the pond wasn't probably super cold, but I wouldn't say above 60-70.

Cells were geforce 6300mah, 40c.

Like I said, this setup has worked for 2 previous outings with no issues.

[Rumdog]

What exactly is going on with the wiring in the pic? Something is looking a bit off

[Peter A]

What exactly is going on with the wiring in the pic? Something is looking a bit off

Yep, it's all blown off!

[lenny]

Well it would be nice to see everything else,
But from what I see in this one picture it does look like a problem waiting to happen.
The water jacket is working at 50% and the wires are way to long.

[dirtnsnowrider]

From your wiring to the batteries. I do not see any shrink wrap around the bullets. If you went underwater, chances are you may have gotten some water inside the hull. The water inside the hull may have arced your battery wires on the esc. The tupperware style secondary hatch does not hold out water, especially under pressure. Even water on the backside of a cap bank will cause it to flare up like a BBQ.

[MrEvoMan]

Well it would be nice to see everything else,
But from what I see in this one picture it does look like a problem waiting to happen.
The water jacket is working at 50% and the wires are way to long.

Why is the water jacket working at 50%?

And the power wires are as short as I can make them. Or are you talking about the motor wires? I'd have to relocate the ESC above the motor for that to be any shorter.