Another question about Feigao motors
 

I've been going back and forth trying to decide which Neu motor to get. I want a Neu for no reason other than the efficiency, or more specifically, cooler running.

My appreciation of what goes on that causes heat is that the heat is caused by the current flowing though the motor. Higher wind motors have more resistance, so they flow less current and run cooler, given a fixed power source. The Feigao, being as inefficient as it is, converts less of the current to power and wastes more as heat than a "good" motor.

When running a 7XL on 4S, it got hot. Really hot. I moved to an 8XL and it got hot too, but not as hot as the 7XL. I tried out a 9XL and that ran even cooler. I'm planning on running a 5S setup, with my sights on 6S when an adequate controller is available.

My question is this...how high a wind do I need to go to before I hit the point where the motor does not generate more heat than the motor case and heatsink can dissipate? I'd like to keep temps in the 150 range.

I realize that there are a lot of variables involved, but I was hoping that some of you could share your real world experiences. I do want to get a Neu, but I'm not going to put a Neu in every vehicle that I have. My wife would shoot me, or stone me to death with all of my motors.

Basically, it takes X amount of power to launch a vehicle to your desired speed with your desired acceleration. That power is volts X current. How you have that arranged is up to you; higher voltage on a higher wind motor (less current) can generate the same power as lower voltage on a lower wind motor (more current). However, there are more losses with high currents.

If you want absolutely cool motor temps, get the appropriately sized motor for your vehicle. A physically motor can dissipate more heat effectively than a small motor - no surprise there. A larger Neu 1515 or an LMT 1950 motor should work splendidly. Then, it's just a matter of choosing a wind count that complements the voltage you want to use to maintain a max of ~30-35krpm.

Is it possible with a cheap motor though. Like a Feigao, or is a Feigao going to get hot no matter what?

So far I've ran two battery packs through my Wanderer 9XL, and it's only getting to 130 +- degrees on 14cells (using a Duratrax handheld). That is with a 38/18 gearing, so nothing very aggressive yet. I have to say, at that gearing, it does seem as fast as it ever was on nitro, nothing official though, that's just by my feel. My limited exerience with these motors would lead me to yes as my opinion on your question. With the right set up and gearing, it's possible.

Yes, it's possible with a cheaper motor. Of course it depends on how cool you want it to run, what performance you expect, and vehicle characteristics. Basically, go with as high voltage as you can on whatever ESC you're running with a higher turn motor.

My hope is that a 12XL on 6S would run reliably cool, altho I think the wait on a MM that ran run a Neu or the LMTs come back in stock may be shorter than a good US-made controller that can reliably run 6S.

Doesn't anyone consider the bk controllers any more? They can run 6s. I run 6s a123 through my bk7020 and a 9xl. I am very happy with it. If you run a higher turn motor you can even get away with the 7020 as I did. Is it because of bad costumer service?

Bingo for me. I have a bad one Mike looked at, but the trouble/$ to have it sent to Ger and the long turn around time makes it a PITA for me. The repairs aren't cheap I understand.

Plus the controllers are not the smoothest or most advanced anymore. Castle and the MMax have spoiled me.

Yeah, in the BKs programming is pretty weak, there is no LVC, service takes a loooong time, and there is no casing to help protect the FETs from shock. They are good controllers though. Sure, not as smooth, but most people don't do too much low speed running when these systems look so much better running fast. :) They do definitely get the job done though and some can handle up to 10s...

I own the 7020 and the mamba max and I think the smoothness of the two are comparable. Although my 7020 is geared low to reduce amp draw in my hyper 7 and the mamba is geared high for speed in my touring car. I'm sure that makes their smoothness seem comparable, but I have very good low speed control on my buggy. I am also using M1 cells so a cut-off is not needed. I guess as long as it doesn't break :013:

AAngel; are you running the smooth or finned can Feigaos'?

I created a program which helps to understand how motor works and how much power is wasted. Planed to add heat losses, but looks like nobody cares...

Griffin: Actually, your program is really nice. I play with it quite a bit to compare various motors. Maybe some just don't know how to use it, know what it is telling them, or how to apply the data in their motor buying decisions?

I run the smooth can motors.

I wonder if the finned can ones run any cooler? Maybe someone with both can chime in here?

I have a fin 7XL motor running 5s2p A123 (crazy power), with heavy bashing on hard pack, after 15 - 20 mins (runtime), the highest I saw the motor at was 150F, that was with a diff problem too, it was binding gears, and the outdrives were seized because I forgot to grease them (it locked diff)

That was geared 51/18 with about 45mph topspeed (Brian's calc)

I wish my motors would run that cool. I'm always in the 160-170 range. What's the temp like where you guys are running. I'm down in Louisiana and it's always hot down here. I don't even own a winter coat.

I would like to see those kind of temps as well, my smooth 7XL gets 170 - 180 after a hard 20 min run, even with the RC-Monster heatsink (cools fast once you stop though).

Yeah, I've taken to making sure that I have a good thermal path from the motor, to the mount and then to the chassis. I've given up on running a fan on the motor. It doesn't seem to do anything for the heat. I think that sufficient sinking is the key.