MM/5700 Issues
 

My cousin recently purchased a MM/5700 setup for his rustler.

Running a 9-cell 4700 pack with maxx sized tires, run great for the first 3 runs.

Then we took it to a construction site, with dirt and really hard grass, and it run fine for about 3 minutes. After that 3 minute run, my cousin stated that the motor was really hot, and the ESC was pretty damn hot too. We let it cool for a good 20 minutes, but it still not not want to work.

Upon me checkin on it, and trying a Warp4 2 Turn BL motor as well as a 7XL with his mamba max, the ESC works perfectly, but as far as I can tell, the 5700 motor is cooked (and it kinda smells that way too)

Has anyone else had this problem? 4 runs and the motor fries?? He has had really bad luck with Castle as of late... he has a 8000kv setup in his Mini LST, and he fried the motor in that the other day too (I haven't doubled checked that yet, he said smoke came out of the motor... so I figure it isn't good)

He is at the point now where, he is going to trade most of his RCs in (probably later today) and either get a nitro or lookin at a new EMaxx.

Any info is appreciated
-Cory

I am not a fan of the CC motors, I have had a few in my RC18 that got really hot, they are a cheap chinses motor that CC puts thier name on, IMO the Feigao is also a chinese motor but made/designed better, and with your 9 cell s you were putting out over 11v (60,000 rpms) thats a lot for that motor, also using an external bec would help with anything over 7v

My first 5700 died after a few minutes on 3s. Castle replaced it, no problem. The replacement has been running on 3s for over a year now.

I have the same setup in a Slash and can't keep my temps under control. ESC and Battery are fine the motor is just won't cooperate. 11/90 and I still hit 200f (motor) on 3s. I've only found one place that makes a smaller pinion. It's a 10t I'm going to try that. If that doesn't work I guess it's time for another motor.

I ran a heatsink with fan in a heavy truck (5lbs) with the 5700 on 3s. Temps are not too bad in my touring car (3lbs) on 3s (no room for heatsink).

also keep in mind the CC motor has a shorter rotor in it versus other 540 sized motors its closer to a 380 size this reduced the torque and causes hotter temps

you had maxx sized tires on a rustler? can i ask why? how goofy is that lol, thats pushing that sucker to the limits

I noticed that after I replied to his post...that was an extra factor on why his motor fried

When it ran.. it actually ran really well, would do rolling wheelies at 30+ MPH

But he did like I said...

Traded in his full FLM rustler with MM and fried 5700, along with a JR XR3 and his brushless Mini LST and got his 3905 E-Maxx

so he solved his issues :no:

I'd like to jump in here and remind everyone -- setup is everything. IF your motor is getting too hot during a run, the gearing is not correct. Brushless will generate as much torque as you ask it to, BUT with poor results if the gearing is wrong.

You should check temps during your first run, and if motor temps are high, gear down. You will often get MORE power and speed with proper gearing than with gearing that is way too high (because the motor is running cooler and in it's operating range.)

Nothing kills a motor faster than incorrect gearing. :wink:

I've run this one with the largest spur and smallest pinion available. I still hit 200f on the motor. I wouldn't think the truck is any heavier than a stampede. In fact the tires are smaller. I don't know what's gone wrong. :neutral:

Thats weird, cuz my heat problems come from my esc. I can run the 6900 on 2s or even 3s all day and it dont break a sweat. I went to play at a construction site, dropped my gear to 15/90 and the esc didnt take long to hit 200. Let it cool, same thing, so I packed it up for the day so I wouldn't break anything. The whole time, the motor was 145ish. Perhaps I should have went with 13t pinion. That low of gearing gets really torquey jumpin around at every touch of the throttle.

I've given up and just ordered another motor. I have a fan on the ESC. That helps keep the temps down on it. I don't think it's gotten over 140f.

Seems odd to have all these variations...

Robert

I run a Feigao 9L on 4s Lipo with an external BEC with my Rustler and all components run good...what motor did you order?

It's Castle 5700. I should have choose the 4600. Glad I didn't get the 7700. :)