Defective motor?or something else?

Consider this an 'inquiry', so as to get a "general consensus opinion".

First, the original configuration: Dynamite 120A ESC, Dynamite 1900kV motor, run ONLY on 4S.
Second, the upgraded configuration: Seaking 180A V3 ESC, Leopard 3674-1400kV motor, run only on 6S.
Props: stock - 43.7mm w/ 1.6 pitch, alternate (CNC 4514) - 45mm w/ 1.4 pitch

Boat is rated for 6S on 'stock' electronics. Based on fully-charged packs, the 1900kV motor should achieve max RPM of just under 32,000 on 4S, and just under 48,000 on 6S. the 1400kV motor, on 6S, should have a max of just over 35,000 RPM.

Now the facts: After switching ESC & motor to the 'upgraded' components, boat was first tested running the stock prop, and the boat was run for approximately four minutes. The first 2-3 minutes, the boat was run full-throttle ONLY in straight lines, with approximately half-throttle when turning the boat around. The boat was then run at full-throttle, in an oval, for the next 90 seconds, and then brought in to have temps taken on all electronics. Other than some "hopping" (indicating the trim tabs might need a slight downward adjustment), the boat runs fine. Temp checks showed everything running quite cool (I don't remember the exact temps, but ESC & motor were below 100, and the two 3S packs (run in-series) were just slightly over 100...in other words, "cool").

I made a slight adjustment (down approx 2mm) to the trim tabs, swapped the stock 4416 prop for the CNC 4514, and swapped the LiPos for a couple of fully-charged packs. I should also mention that another boat was running during this time, so I waited until the other boat was back to shore before putting my boat back in the water again, which was approx 10 minutes. Following the exact same testing procedure, the first 2-3 minutes were spent doing straight full-throttle sprints, with "cool down" periods of half-throttle at each end while turning the boat around. This was to be followed by the same 90 seconds of ovals at full-throttle. Unfortunately, after completing the second lap, and just past halfway through the first turn on the third lap, the boat 'stopped'...she was "dead in the water". It took about 15 minutes to recover, and, upon recovery, I noticed the distinct 'hum' of the servo, telling me that it wasn't the batteries (initially, I thought the LVC had failed, and the boat had no power), and, in all likelihood, the Rx & ESC were probably fine.

As soon as we were back to the workbench, I immediately removed the canopy, and a tiny 'whiff' of smoke exited. I took temp readings, and, while the batteries and ESC were slightly 'warm', it was the motor that worried me - after 15 minutes, the motor was hot...as in, 130 degrees. I quickly grabbed my Tx (I know what you're all thinking -- I should have immediately unplugged the batteries), and tested the steering, and the rudder turned both directions. So, I knew the servo & Rx were fine, and (once again), in all probability, the ESC was fine. Next, I tested the throttle...and nothing. Now, I disconnected the batteries, worried that this brand-new motor, which should have been running cooler than the stock electronics, was fried. It wasn't until a couple minutes later that I noticed one of the wires coming from the motor was no longer connected to the bullet connector, at which point I thought the motor might be ok.

Here's the thing about the bullets - the stock bullets that came on the motor were 6mm, and the stock bullets that came on the ESC were 5.5mm (I know they're listed as '6mm', but, in truth, they're closer to 5.5mm, as they just fell out of the motor's bullets)...so, I cut off the ESCcs bullets, and soldered on the bullets that came with the motor. As such, all three bullets on the ESC's side of the connection were soldered by me, and all three bullets on the motor's side were soldered by Leopard. This led me to believe that Leopard did a sub-par soldering job, and, in re-soldering the "detached" bullet, I had also planned on checking the other two.

However...and, it's a big HOWEVER...I am no longer going to be re-soldering the bullet. In further troubleshooting, I discovered that the insides of the motor are 'toast'. No, I didn't take it apart...I didn't need to. If you look at what I saw, looking into the end of the motor, you will see.https://uploads.tapatalk-cdn.com/202...ef3f9e0ef5.jpg
You could say that the motor attempted to pull more amperage than the ESC could supply...but, considering that the motor draws a maximum of 58A, and the ESC runs at a 'constant' of 180A, this wouldn't make any sense. Likewise, one could say that a load increase caused the motor to excessively heat, which would have fried the motor, and, in turn, could have caused the bullet to de-solder. Unfortunately, this also doesn't make any sense, as the 1mm larger diameter prop had a much lower pitch (1.4 vs the stock prop's 1.6), thus the load on the motor was lessened, thus the electronics would have been even cooler. For those thinking "something else", such as moss bound up in the prop, know that the prop, strut, and rudder were clean as a whistle. This was a brand-new motor, being powered by a brand-new ESC. I had previously assumed that the ESC, Rx, and servo were all still good...and, two days later (today), I confirmed this, by connecting a different motor to the ESC, and testing everything...and everything worked.

So, WHAT went wrong? This is the reason for this thread. Based on the facts, the only logical conclusion I can come up with is that the motor was defective. I might still be somewhat new to FE boats, as well as marine RC motors...but, I am more than familiar enough with RC motors, in general. I understand that 99.9% (probably higher) of RC motors have no problems...but, that doesn't remove the fact that, every so often, there will be a motor with a defect...and, unfortunately, I believe that I got that 0.1%. I'd like to hear other people's thoughts. Based on all the facts provided, what do you think? I would really like to know other people's opinions on this matter.

Where are you getting 58 amps from? Is that the rated amps for the motor? Your actual amperage is what kills the motor. That's the be a result of the boat, how wet is it, is there any binding, the props size, etc, etc, etc. The motor doesn't get to it's 58 amp max rating and stop. That's what the manufacturer is telling you to stay under. Which we all promptly ignore by the way.

Also, you ran 2 to 3 minutes of straights and then ran another 90 seconds of ovals? So 3.5 to 4.5 minutes of run time. I don't own a single boat that will run that long. So you're problem is likely two fold. Too much prop for the motor and too long of a run. That is assuming there is no drive line binding and it's not running super wet or something.

That little wisp of smoke was the enamel burning off of your magnet wires. Been there too. That's what you see when you peak into the end of the motor. That black stuff on the copper wires is the burned enamel. That's the disadvantage to less pricey motors. They use lower temp wire.

Quote:

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Originally Posted by T.S.Davis

Where are you getting 58 amps from? Is that the rated amps for the motor? Your actual amperage is what kills the motor. That's the be a result of the boat, how wet is it, is there any binding, the props size, etc, etc, etc. The motor doesn't get to it's 58 amp max rating and stop. That's what the manufacturer is telling you to stay under. Which we all promptly ignore by the way.

Also, you ran 2 to 3 minutes of straights and then ran another 90 seconds of ovals? So 3.5 to 4.5 minutes of run time. I don't own a single boat that will run that long. So you're problem is likely two fold. Too much prop for the motor and too long of a run. That is assuming there is no drive line binding and it's not running super wet or something.

That little wisp of smoke was the enamel burning off of your magnet wires. Been there too. That's what you see when you peak into the end of the motor. That black stuff on the copper wires is the burned enamel. That's the disadvantage to less pricey motors. They use lower temp wire.

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58A would be the "continuous operating amperage" of the motor. Obviously, when throttle is applied, the actual amperage draw from the motor exceeds that. With some motors, the instantaneous draw can be 3-4x the 'continuous', which is exactly why ESCs have 'continuous', and we'll add meeting 'burst' ratings. For example, the Seaking 180A V3 ESC is 'continuous' rated up to 180A, and 'burst' rated up to 1080A.

As for runtime, your "math" isn't adding up, because you are only taking "continuous full-throttle time" into consideration. With the original 1900kV motor, running 5000mAh of 6S (or two 2S), typical runtime was 3.5 minutes. Having dropped down to a 1400kV motor, running the same amount of mAh, runtime would increase. On top of that, you're also ignoring the turn-around points I mentioned, each of which took longer than the actual full-throttle SAW runs, to which I also started that a MAXIMUM of half-throttle was used. That doesn't mean half-throttle the entire 'turn-around' time...it, obviously, includes time just sitting there.

As for the prop, it was definitely NOT "too much". I'm guessing you didn't fully read my initial thread. For the first test run, I ran the stock prop, which is 44mm, work a 1.6 pitch, and EVERYTHING was cool...as in, barely 100?. For the second test run, while the prop was larger (45mm), the porch was MUCH lower (1.4), so the total pitch was lower, thus the load on the motor was also lower.

As for the "price of the motor", not everyone can afford to spend $150, or more, on TP motors...and, besides, Leopard motors are not exactly "cheap". Last time I checked, $70 was NOT "cheap".


~ More peace, love, laughter, & kindness would make the world a MUCH better place

Here's a new thought, and a new question, on the problem at hand.

The only way to prove that the motor was defective might be to disassemble the motor. I'm not saying this WILL prove it...but, it might be the only way to prove it. If that's the case, how do I disassemble the motor? I've never disassembled...actually, I've never had as need to disassemble, an I've NEVER had any problems work any of my motors before now...a motor before. I removed the three screws on the can, at the end opposite the motor shaft, but that's didn't accomplish anything.

If someone could direct me in disassembling the Leopard 3674-1400kV motor, is greatly appreciate it. Additionally, of anyone can tell me what, exactly, I should be looking for, that could help me even more. Common things (bad bearing, magnet not glued in place) I am sure I can figure out...it's the less common defects I'm interested in knowing what to look for. Since Steve doesn't appear to be willing to help, I guess it's up to me to either price the motor was defective, or to discover it wasn't...but, I could really use some help in making that determination.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

Good news...I'm not 100% certain, but I have a super-incredibly-strong feeling that nothing is wrong with the motor (and, I've already notified Steve as such). As I said if do, I resoldered the bullet connector, and did some very-quick testing (literally, as in less than 20 seconds worth) on a partially-charged 3S...and, the motor (not installed into the boat) operated perfectly well. So, after fully charging a 4S, as well as two 3S, I set about further testing.

First, I tested the motor on 4S, which I broke into two sub-tests - the first with absolutely no load (motor still not installed back into the boat), and the second with some load (motor installed, flex cable tightened into coupler, but no prop). For each sub-test, I ran the motor at full-throttle for 3 minutes. Not only that, but, after both tests, and having been run at full-throttle for 6 minutes, all four cells still had 4.138V remaining.https://uploads.tapatalk-cdn.com/202...e13f6727be.jpg
For the "naysayers" that say 6 minutes is impossible...especially having that much voltage still remaining...no, it isn't. Remember, the motor had either no load (1st test, not installed), or very minimal load (2nd test, can installed & flex cable attached). Temps for ESC, motor, and battery, were all near 80? when I started. The battery & ESC both peaked at 88?, while the motor (no cooling) reached 98.6? (yes, I know..."interesting" temperature to have reached...I laughed, too). After the first test, I disconnected the battery, went about installing the motor, and then attaching the flex cable...time spent was approx 5min. After the second test, the ESC & battery were both in the very-low 90s, and the motor peaked at 126.2? (remember, no cooling).

Before doing the 6S testing, I decided to wait until the motor's temp was below 85? (approx 25min). While I did so, I also went about rechecking the ESC's programming. Settings were '1' (forward only), '4' (4S...I'll explain this, shortly), '4' (3.2V/cell LVC), & '5' (15.00? timing). First, the 4S setting...I had forgotten that, during the initial programming, I had changed the ESC, from 'Auto', to 4S, as I had initially planned to run 4S for the first day of in-water testing. I changed my mind, decided to stick with 6S (the intended power for the "upgraded" boat), but forgot to reprogram the ESC. I don't know for certain, but this might have led to the boat's motor having no power when it 'died' in the water. Before running the 6S test, I changed that seeing to '6' (6S). As for the timing, based on input from a few others, including someone who's responded to this thread, I've changed the timing to '4' (11.25?, which is still within this wind's 10-15? range).

So, what happened in the 6S test? Once again, remember that this was NOT an in-water test...test was done on my front porch, and the only 'load' was the flex cable/prop shaft, with no prop installed (why would I need a prop, especially if the boat was in its carrier). After running at full-their for the minutes, the motor hit a max of 149.8?, the ESC hit 87.6?, and both 3S packs hit 82.2? (series, for 6S). While I was at it, I decided to also hit the bullet connectors work the temp gun (call me 'curious'...the temps were as follows - 89.2? (blue), 91.1? (peach), & 85.4? (yellow). Note that the yellow connector...the very connector that had become 'de-soldered'...was the coolest of the three. Interesting? Or, no?

Anyway I the next testing will be done at the pond. This time around, I plan to do the testing slightly different - I'll do 2min of SAW runs, with approx 15sec between each run (the "turn-around" points), then being her in for temp readings. If all is good, I'll send her back out for 2min of full-throttle runs, then being her back in for temp readings. If all is still good, I'll give her a 20-30min rest, while I swap props to the next size, and then repeat the process.

The best news of all: The motor appears to be in great condition. Now, an for what caused the motor's yellow bullet to "disengage" from the wire, I may never know...but, I am certain that it was never soldered properly at the factory - a problem I was, thankfully, able to correct. I now consider this matter "closed". If there are any further updates, I will post them in the OSE forum, in the SonicWake thread.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

Okay, let me understand this. The OP is asking why he has a problem with his boat. One of the most experienced FE boaters on the planet gives him advice (very good advice BTW). The OP ignores it and starts arguing with him, clearly without understanding what Terry posted. I guess he knows the answers afterall. Good luck OP.




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Dude, yer motors toast.

1) The motor is NOT 'toast'. If you bothered to read my last post, you'd have known that it was finally determined to be nothing more than a connector that "disengaged" from the wire...which, in all honesty, is exactly what I had initially thought had happened. I only starting thinking that the motor might have been fried because a few certain people in the OSE & RC Groups forums 'decided' that, without first having had the full information.

2). I don't care who 'Terry' is if he doesn't bother to listen (or read) everything that has been said. I don't mean to sound negative in this...but, let me all those reading this. If you were having a conversion with a group of people, and amongst that group was one of the most intelligent people the world has even known...say, Albert Einstein...and Professor Einstein commented on the matter, but, in doing so, you could tell that he hasn't actually paid any attention to what you were saying, would what he said matter? The truth is, no, it wouldn't. It has nothing to do with him being intelligent...it has to do, purely, with the fact that he hadn't paid attention to everything that was said, and that his response made no sense, at least in regards to what was being commented on.

It didn't seem to matter how many times I proved that the 'load' on the second run was less (or, at worst, the same as taking the trim tab adjustment into consideration) than the 'load' on the first run. He also didn't bother to consider (which he could have very easily found a baby reading other SonicWake threads) that the "upgraded" electronics put a considerable lesser 'load' on the boat when compared to the stock electronics. One final time, even a person with very little understanding of electronics could focus that out based in the information provided.

However, none of this matters anymore, as the motor IS operational, it IS running perfectly fine, and it IS running cooler.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

Wow........

A picture can say a thousand words however, in this case one is only needed.. Burnt.

The windings are burnt. I have an 1800Kv Aquacraft motor that looks the same, it still runs but I don't run it anymore because as soon as the next heavy load is applied I can say bye bye to my ESC and the motor will then finish itself off.

It took about 4 Aquacraft motors for me to figure out I was overloading it. That was about 10 years ago and I don't do these things now because I'm cheap. Now if I burn a motor it's a calculated risk to try and beat someone in a real race since I figured out what load I could apply to it.

Quote:

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Originally Posted by ray schrauwen

A picture can say a thousand words however, in this case one is only needed.. Burnt.

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Honestly, I completely understand what you're saying. However, after looking at the photo again, and looking at the motor, I have to admit that the photo is very deceiving. If I were to base my decision only off the photo, is probably agree with you. But, when I look at the motor in better light (the photo was taken in a somewhat dimly-lit bedroom, with an LED light that has a slight orangish color), I don't see "burnt orange"...I see copper, as clear as day.

I'll try to get a better photo...maybe remove the motor again, take it outside, and take a new photo...and then post that one. The color in the photo I originally posted is definitely 'off'.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

Thanks Jay.

I wont contribute any further. I thought we were going to have a conversation. We aren't.

To be on the "safe side", I've decided to order another motor. I understand what's been said, and, if I'm wrong (which I could still be), then I'd rather be "safe than sorry". If it's needed, I'll have it...and, even if it doesn't end up in this boat, I can always put it in another. I'm working on an OSE order right now (for something else that I'll be building), and can add the motor to that order.

Question is, should I get another of the same, or something different...and, if different, what would those-in-the-know suggest/recommend?

I don't want to modify the motor mount, so a 36mm can is the only diameter option. In regards to output, I'd prefer to remain closed to the 1400kV of the current motor - nothing larger than 1500kV, nothing smaller than 1200kV, and nothing shorter than 74mm (anything shorter won't fit the motor mount's rear bracket).


~ More peace, love, laughter, & kindness would make the world a MUCH better place

The 58amps rating for the motor is the max current rating.

The max current rating is not the same as continuios current.

If you are doing 2 or 3 passes running max current is ok. And you can get away with a little more than max if you are doing 2 to 3 wide open passes and bring the boat back in to cool down.

If you intent to do continuios running a safe current would be half of the max current rating.

That is 29 amps for that 3674 1400kv leopard.

The reason why you encounted that issue is because your runtime was too long.

That setup with the 45 mm prop on 6s is a 2 to 3 pass setup and come in.

That setup is like pulling 100 amps or a little more.

The 2 to 3 minutes full throttle passes is way too much. Then to add 90 seconds of wide open oval running that is like locking up a man and throwing the keys away.

If you want to do you that kind of running, you can try a 42mm prop and 4s.

The boat will be slow with a 1400kv, 4s and a 42mm prop but you might get your runtime without damaging anything.