Motor Overheating or Over-Propping

[10gauge]

Did I over-prop a 9XL with a m545 or did my motor overheat due to the choppy conditions?...

I had a very unusual run - after 3 minutes of running under windy and choppy conditions, my Mean Machine slowed down to almost a stop on the lake. After 1 minute, I regained throttle, but only about 30 seconds. The boat was moving very slowly again even with full throttle. So I bought it in...

No binding in the HW. The ESC and 4S LiPos were just warm to the touch, but the motor temp was hot. However, the motor mount and flex coupler were so hot that the water from my hand sizzled. The motor has run only 6 times with an m440, x442, x445 with no overheating issues. This last run was with a m545.

I am trying to determine if the chop had anything to do with the motor overheating where the hull was in mid-air half the time. I am wondering if the current peaked because of the bouncy chop or if the m545 was just too much for the 9XL? I thought that 9XL and m545 combination would be ideal?... I don't know if the motor is history now that the magnets have overheated?... If it is, then it's time for a Neu 1515/2200kv!

Setup: Mean Machine Hull, Speedmaster HW, 9XL-1853kv, 4S2P/8200mAh/15C, m545

[SJFE]

The fact your coupler and shaft where hot makes me think you may have a beat bearing. Just a guess.

[Ocean Racer]

From my little experience and understanding chop would do very little so you might have to much prop. Do you have a good solid cooling system?

[Mich. Maniac]

The fact your coupler and shaft where hot makes me think you may have a beat bearing. Just a guess.

However this is a quote from another thread: imagine a bunch of spikes in amps and voltage one after the other... that would generate heat in the best of the motors.

[NorthernBoater]

How new is the flex cable? A new flex cable will wind up some and it would put more load on the motor. I have always left a small gap to account for this.

[10gauge]

Ahh, Sometimes when it happens to you, you're at a loss of ideas. I knew I'd get good responses from you guys!

OceanRacer: I saw that the cooling system was running adequately.

Yes NorthearnBoater, on this run, the flex cable was NEW! I had a 3mm gap between the drive dog and strut where I had placed a small piece of fuel tubing which I learned from ReddyWatts. The small fuel tubing was crunched - so there must have been a lot of flex cable contraction, hence friction and current load! You know, I've never tried to "break-in" a flex cable.... Maybe I should do that!

SJFE, I do have a spare bearing. Even though it's a Feigao, I thought I'd get more than just 6 runs on a stock bearing. I even was running a 5mm thrust bearing ahead of the coupler. But, I'll look into that too.

Thanks everyone for the great advice!

[10gauge]

Oh, almost forgot, thanks Mich too - the cumulative effect of the current spikes makes a lot of sense. It's worth linking a data logger just to see the effects of chop bounce and peak current over time.

[NorthernBoater]

I have had the flex cable contract before to the point where the coupler was hot. Try leaving a larger gap next time and run it for 30 seconds and see how it is. It should have done no permanent damage.

[ReddyWatts]

Sounds like you need more gap or less tubing. It should not be crunched. That could be causing your problem.

[properchopper]

A while ago I had a brand new, never run Hydra 240 in my Titan 29, 9XL, 4S2p with a M545 that ran good with NIMH. I put 'er in with the lipos, punched the throttle[Wrong !]. She jumped straight up, spun like a football, & ate the 240. I now run a X442 for offshore or a M445 for oval, watch the dead-start throttling & all is good. I realize that the Titan has more hull drag than the MM, but who knows ? Just my 2 cents.

[10gauge]

Yes, ReddyWatts, I am going to run the same flex with more gap distance.

Properchopper, I am stunned that a Hydra 240 expired on a 9XL m545 combo!

I am going to install a V3 data logger and mount a plexiglass into the top deck so that I can read the LCD display without having to unstrap the tape on the canopy - as opposed to a laptop or taking readings well after I am home from the lake.

[properchopper]

[QUOTE=10gauge;40421]

Properchopper, I am stunned that a Hydra 240 expired on a 9XL m545 combo!

I had the startup setting wrong, and I mean I really PUNCHED the throttle from rest. The startup spike reached way too many amps. I've since learned to get on the throttle easy. Eliminates those embarrasing wheelies/backflips