Shocker First Maiden Run -- ESC Literally BLOWS through Hull

[kevinpratt823]

It is really a bad idea to run these motors like that with no load, especially at full throttle for any duration.

[SD Eracer]

Hmmmmm, our little group of weekend warriors run in salt water at the San Diego model yacht pond almost every weekend. All of us pretty much run on the SeaKing 180a V3, and it has been a tale of two cities between us. Some with zero issues, some with constant blow ups.

Over the year I've been running with this group, I can tell you that almost every single V3 failure was due to user error. The majority of those failures were people running 6S setups on 5S speced motors.

Another issue was that running exclusively in ocean water, some people weren't too careful about getting saltwater into their boats and not cleaning off the ESC's, especially the stock capacitor banks. I would find most of them were already popped or corroded due to saltwater without them knowing since those components are covered in heat shrink and hard to see. This I suspect would leave their ESCs susceptible to failure.

The other group that has no failures, we have been pretty proactive in protecting our boats. If you run close to the edge, doing a few things will help protect your investment, such as upgraded capacitor banks, going BEC-less, running higher C rated batteries, 8mm connectors, etc.

If you check out TheShaddix's posts, he does a really cool upgraded cooling system on the V3. He has several high speed cats running exclusively on 180a V3s with no failures.

I personally have been running a somewhat borderline setup on my Genesis Cat (Leopard 4092 1730kv (20 volt rated) on 6S with a SAW setups using the V3. I'm either at 0% or 100% throttle, and at 100 percent power for only a few seconds before I'm off plane and turning to get another pass. I've had over 250 full throttle passes in the last month with this setup with no issues, running a M445 prop. Motor temp is usually 115F, the ESC at 125F at the base, cap bank at 145F.

[dmitry100]

Yea but wouldn't it be better though to test them that way and finding out that they're no good that way than finding out through another blown ESC though?

Or should I try putting them under load and then seeing how it goes? The heat seems excessive... could only imagine how hot they would get with load :-/
Perhaps it might be worth a shot putting them under load for a very limited and short run?

[tlandauer]

Man, 20-30 sec. of WOT bench testing is an eternity. Not surprisingly you read those temperature. When we want to test the rotation of the motor or check the bearing, we merely blip the throttle and never full. I understand your argument that it's better to find out on the bench, but as said, no load full throttle is not a good practice.
At this juncture, if I were you I will consider not using these motors, Leopard motors or TP motors are quite good for sport boating and you will save yourself a lot of headaches down the road.
Just my $.02
Cheers

Sent from my D6708 using Tapatalk

[dmitry100]

Yea, I get what you're saying.

I might as well just ship them back where I got them... and have the guy just refund the price diff from the rest of the boat.
They seem like junk quality compared to TP 4050 that I have... and they're apparently similar in price. Which is ridiculous.

[dmitry100]

What do you guys think of these teflon tubes?

It seems like they are always at an angle like this... and extend past the hull into the drives but the drive strut happens to be a lot bigger in diameter than the teflon that goes into it.
So the teflon always ends up being at a slight angle especially even when the driveline is completely put together.

Anything I should do about this? perhaps replace the teflon tubings with some new ones? or should I cut them so that they aren't sticking out like that or just try to straighten them out somehow...
I wonder if this would cause unnecessary resistance in the driveline...

(4th picture) I also did some work on the hull water intakes... made the tear drop longer and deeper, and just increased the overall diameter of the inlet hole. That took a little while to do-- carbon is surprisingly super strong and I think I dulled some drill bits in the process but I did use a bit of water to avoid overheating the bits and breathing the fibers. They look better now? Was thinking if I should maybe make the tear drops a tad bit longer or not...





Here a pic of the modified water intakes:

[tlandauer]

The teflon liner goes into the drive normally, but I am not familiar with your particular one, in any case, it can't go beyond the bushings. It should not give you an unreasonable amount of drag. Shortening it too much might invite water up the stuffing tube.
The condition looks ok to me.
Your tear drop shaped intakes look great!

[T.S.Davis]

If the trailing edge of the water pickups is still at 90 degrees to the running surface they're still not going to pick up much water. Think of it like a snow shovel. If you tried to push it with the blade straight up and down it doesn't actually lift the snow. If the blade of the shovel is at an angle it picks up snow. Same thing here.

A note to everyone. Be careful bench testing. Full rpm with no load is not ideal. I used to do this all the time. Really sounds cool on a wire drive. Then one time I had a stub shaft let go. It bent right at the strut and threw the prop. Hit me right in the throat. No damage. I was extremely lucky. Please learn from my stupidity.

[dmitry100]

Damn ... so the tear drops aren't gonna that much more in this case even if they're at 90* angle? I was actually thinking about getting some tiny 6v or 12v water pumps... that way it'd be pushing water through and cooling everything down even when it's at a slow or idle speed by the time I go for another high speed pass, etc.

tlandauer: So the teflon tubes being kinda bent in the strut there like that isn't a big deal then? perhaps it'd be best to maybe using a small torch to straighten out a bit more... so that the part of the teflon in strut is at less of an angle?

[T.S.Davis]

tlandauer: So the teflon tubes being kinda bent in the strut there like that isn't a big deal then? perhaps it'd be best to maybe using a small torch to straighten out a bit more... so that the part of the teflon in strut is at less of an angle?

As long as the teflon isn't jammed up against the bushings in the strut you'll be fine as is. The teflon offers almost no resistance unless it's able to grab on somehow. It would need to squeeze the flex if you can picture what I'm saying.

[tlandauer]

While it is desirable to have the trailing edge of the tear drop pick up rigged at an angle, I had no space in my build (other than having the pick up tube placed straight up) and did just what you had done and was fine. DSCN7351.jpg DSCN7358.jpg
I am by no means contradicting what's been said, I just want to chime in and say that this will give you water. The shaping of the channel is very important as well and you have corrected the shape.
All new teflon liners come wrapped in a circle, when you place them in the drive, there is a curve . I have not tried to straighten them out and I don't actually know if they respond to heat or not, you can try. Granted, my don't protrude that much, I used stingers and drives where only less than 1/2 inch sticks out and the curve does not have a chance to add drag yet at that length. I prefer to have the curve where the liner is inside the brass tube as it adds resistance to turn along with the cable.
I want to ask you this, if you take the liner out and try to stick it into the drive barrel, how far does it go before hitting the bushings? Show us a picture.....

[ray schrauwen]

The flaring on the teflon looks like it may have been compressed when the strut is over top of it. If the teflon is not able to come out of the motor end and is slightly too long to fit in between the strut and what stops it inside, it could add a bend that might increase friction....??? Just adding to what Terry said and tossing ideas out there... Nice hardware though, motor mounts and all...

As long as the teflon isn't jammed up against the bushings in the strut you'll be fine as is. The teflon offers almost no resistance unless it's able to grab on somehow. It would need to squeeze the flex if you can picture what I'm saying.

[dmitry100]

Ray: http://forums.offshoreelectrics.com/...9&d=1431285547

Thats the picture of how much of the tube goes inside the drive. I'll add another picture, but no part of the drive should be jamming against the teflon though... as the shaft is way up ahead. The flexs do sometimes take a bit of work to go inside-- its not a direct bullseye when you push the flexs down the driveline... since the teflon is a bit of a curve and the strut itself is not the perfect diameter like the brass tube is.

If you look at the picture with the tear drops you will notice the flex/shaft of the drives on the left side of the picture.

[iridebikes247]

The tear drop looks good, cooling will not be an issue. I have the tear drops that look similar on all of my builds, cooling is never a problem.

[dmitry100]

I *HATE* hate hate hate soldering 10 gauge wire with a passion.

Here's what I was doing just now. I seriously need to get some sort of mask for soldering.

I give up on it for now. I'll try to make it a little more prettier later but original plan was to solder it perfectly between the two wires...