mmm + fiegao + Nue + muggy = hot hot hot

[Gooberseptember]

Ok im new to posting, but have read just about every thread i could for the last yr or so.

I am not new to brushless conversions. I have about 9 or so under my belt.

Here is my problem:
first conversion on muggy:
stock losi muggy
fiegao 10xl
12t pinion
max amps 5cell 6000mah lipo
MMM

This resulted in fried motor on second run. (smoked alot) The motor and RCM heatsink was so hot i could feel the heat from about 5 in away.
The first run was smooth, the motor was hot, but nothing hotter than what the fiegao normally gets.(i have had a few of these motors)

Battery was hot also. Sorry not temp gun.

So at this point i just thought i had a bad motor so i emailed Mike, but he seems to be busy. So no problem, i ordered another motor. This time a Neu.(from another site, mike was out of stock)

Setup #2.

Same as above ,but now with the Neu 1515/2.5d with out fins.(only one i found in stock)

Now i took it out and felt the motor every min for 4 min. The MMM fan kicked on and stayed on within the first min. The motor at end of min 4 was just hot enough that i could only hold my hand on it for a few seconds.

This is my problem.
There is no binding rolls smooth.
Pinion is set perfect.
The pig comes in aroung 12lbs.

MMM settings are set to low everything.(i thought it would run cooler, i could be wrong)

Any help would be great.

Oh yeah, both setups are as per MIke. So i trust them. ???

Michael

[lincpimp]

Try a 10t pinion and see if that helps temps...

[Gooberseptember]

What about MMM settings? I have read people running this setup with great success. Are my setting correct at low or should i set them high since i now have all highend componets?

[lincpimp]

Originally Posted by Gooberseptember

What about MMM settings? I have read people running this setup with great success. Are my setting correct at low or should i set them high since i now have all highend componets?

I usually leave the settings at all stock settings.

[gimpygolden]

Well Neus don't really like much timing, but you could try to raise the start power see what happens.
Oh and i like your Av pic funny stuff.

[Gooberseptember]

Think that may help? LOL

[Gooberseptember]

my first love is heli's. Yes there is a heli in my Av. LOL

[Gooberseptember]

my timing was set to low (0) its now set to normal (10) (stock setting)

[Gooberseptember]

Ok i just got back in.

Changes-
start power to medium.
all other MMM set to stock

4 min run and i could only hold my finger on motor for a sec or 2

MMM fan was running during most of the run. ???

[lincpimp]

What weight oil are you running in the center diff, and do you notice the front tires ballooning much more than the rears?

Also, what tires are you running?

[Gooberseptember]

The center diff is almost locked. When it had 30000 wt the front tires would balloon like crazy and it would be like a front wheel drive truck. LOL

I think they are stock. (bought the roller used)

[BrianG]

I don't know much about a Muggy, but does it have a center diff? Brushless has a lot more torque than a nitro so it is much easier to have the front unload a lot on take-off. This basically unloads the motor to where it spins relatively unloaded making it hot. I would try some thicker oil in there, 50k as a minimum IMO.

That could explain motor temps, but not ESC temps. That usually means you are overgeared when both are hot. Have you tried gearing down as Lincpimp suggested? You may not like the resulting lower top speed, but it's a place to start.

Also, I would set the punch control as high as possible before you don't like the loss in take-off punch. This will help tame that initial high current burst and should lower temps.

Usually, in such a heavy vehicle, I would suggest 6s on a 1800kv motor, but that combo you have should be perfectly fine geared right.

[Gooberseptember]

I used the super heavy diff locker stuff. (doesnt fully lock it, but its pretty good)

I just upped my punch control to 50%.


The wheels are stock but the tires are not.

Just as a small test of the MMM fan, i just flipped my buggy over and ran it unloaded till the fan kicked on. (not to long) The fan kicked on for about 15 sec and shut back off. So its working right.

more testing tomorrow.

Thanks all!!

[lincpimp]

Looking at the motor, on 5s it is spinning at 30k max. Seems a bit slow to me. I prefer a higher kv motor on a heavy truck with lower gearing. Seems to work better than a slower spinning motor with high gearing. The muggy has quite high gearing stock, nitro users have clutch problems due to the load of the heavy chassis and tires. Diffs are 11/45, but it really needs a bigger center spur, at least a 50t like the hb lsp truggy...

[Gooberseptember]

Mike recommed this setup. I may go with the poline tires and rims to save some weight.