MM is way too hot! Why?

[Xtremespeed]

I just got my Neu 1512 1.5d/f this week. Running it on 4s2p A123, 14/46 in a hyper8 pro. The new motor is making a lot of power, and staying very cool. Hasn't been over 110 yet. After running no more than 2 minutes around the living room I heard my MM reboot. Checked the temp and it was 271 It was getting very hot with my Feigao, and I was hoping it was the motor, as the Feigao was also running very hot (210). The Neu is running cool though, so now I'm a little stumped. Obviously I'm not running the car too hard in my living room. What am I missing? Is my MM done?

[glassdoctor]

You running a ubec ?
Even without one I can't see how it should thermal in 2 minutes in the living room...

Unless it is cogging a lot... that makes it very hot very fast.

[Serum]

some kind of binding in the drivetrain perhaps?

[Xtremespeed]

I'm running a ubec, and removed the red wire from the MM. I double checked everything when I put the motor on and everything is free.

[glassdoctor]

Does it ever cog on startup? If it cogs bad even once and you pull much throttle, that can get it hot.

Try running it outside where it can run free and see what happens.

EDIT: ok.. I see you have the 1.5d not the 1.5y.... (please list the kv)

That may be the problem. You need to gear it down to about 10/46. 3200kv is a very hot motor so you are overgeared pretty bad right now for anything but speed runs.

[MetalMan]

I too think you are geared too high. I'm running similar gearing on my Hyper 8 Pro, but with the 2.5D/F and 4s Lipo, and with the MM. My MM has yet to thermal with this setup on a track, and there aren't any fans.

[Xtremespeed]

Would the motor not run hot if it was overgeared that bad? I built this car for bashing and don't really have much interest in gearing way down as I don't have to drive real technical like on a track. I actually have some larger pinions I would like to try, but I think several people have run the 1.5d with 13-14/46 and had good results. I'm more into the wow factor I guess. Anyways, I've tried running it outside, and it's the same, just thought I would try some short bursts in the house to see what happened. I understand speed runs will heat everything up with my larger pinions, but could I get away with the 14/46 with another controller maybe?

[glassdoctor]

IMO nothing in the price range of the MM can hang with it... you have to look at the @$300 controllers to get much better as far as what it can handle.

The motor would eventually run hot too... but the esc will be the first to run hot when overgeared (typically)

[Xtremespeed]

Just a quick update. Changed my pinion to a 13t this morning and went outside. My Neu was at 112 after about 10min pretty hard running and the MM about 190. I can't hardly tell the difference in top speed between the 2. Cogging is non-existant except for if I try to go full throttle from a dead stop. I had ordered a couple fans already, and they should be here tomorrow. This may be ok once I drill the case and get the fans on there. At least I think it will get me by until a better esc comes along. Thanks everyone for the help.

[glassdoctor]

Now try a 12t pinion... ;)

[lxmuff]

As mentioned before, try 12T next. You have lots of motor left.

[Happywing]

You'll be able to smoke any nitro with the 12T. If you ever race, you'd want to go to a 10 or 11. The MM hole mod, a fan and the 12T will give you a long cool run.

[miniGranis]

Originally Posted by Happywing

..The MM hole mod, a fan and the 12T will give you a long cool run.

What mod is that ?

[BrianG]

Drilling several small holes in the plastic case to allow better cooling for the bottom FET layer and the BEC section.

[miniGranis]

Aha thanks, anyone got any pics ?