Mojave Mojave 2050kv motor overheating

[Wraith405]

All,

Anyone else with a Mojave 6S having major overheating issues with the stock motor? my two last runs with a full battery ended up at 210 and 205 F. I don't think I am going too crazy with the throttle, but these temps are way too high for my liking.

Ambient temperature was around 75 F.

Batteries were 6S HRB 6000Mah 50C lipos both time.

Running in very short grass and dirt.

Any ideas? Should I install a motor heatsink and fan? Maybe change the pinion down to a 15T or 14T? The 16T seems a little bit aggressive, considering how big and heavy this thing is. I mean, my kraton runs on a 12T.

 

[crimsonfancy]

How long does it take to go through one pack?
If you're wide open most of the time I imagine heat in short grass and dirt. If this is normal driving then I'd def get a fan etc at least because it can't hurt. I'd then look at temps again after fan install and see if you'll have to sacrifice a step in pinion.
This is how Id go about it anyway.

 

[jondilly1974]

Dual fans like @Mr.Duke does

 

[Yonic]

I would check for bearings.

Take out the center diff and spin both the front and rear drive trains (with the wheels off) to check if they are free.
with the center diff still out, connect a battery and give some throttle to the motor, it should spin smoothly.

 

[LibertyMKiii]

Any ideas? Should I install a motor heatsink and fan? Maybe change the pinion down to a 15T or 14T? The 16T seems a little bit aggressive, considering how big and heavy this thing is. I mean, my kraton runs on a 12T.

I would change the gear down like you have on your Kraton and might also need the fan/heatsink setup.
Not surprised at all that it would get hot with a 15t or 16t pinion given the vehicle size and weight.

-Liberty

 

[Wraith405]

I would change the gear down like you have on your Kraton and might also need the fan/heatsink setup.
Not surprised at all that it would get hot with a 15t or 16t pinion given the vehicle size and weight.

-Liberty

Yeah I think Arrma figured it would fine, given that it's using truggy size wheels and tires instead of the larger monster truck style. I'll change down to a 15T and test that out. Luckily this new V4 motor mount makes changes super easy. Might as well go ahead and grab a Yeah racing dual fan setup.

I would check for bearings.

Take out the center diff and spin both the front and rear drive trains (with the wheels off) to check if they are free.
with the center diff still out, connect a battery and give some throttle to the motor, it should spin smoothly.

Can't hurt to check the bearings. I have a few bearings left over from a Fast Eddy kit I got for my Kraton so I should have a few spares in case something's bad somewhere.

 

[Wraith405]

So I changed it down to a 15T pinion. After a good hard 6S bash, the motor temped at 170 F. I don't love the slight loss of speed and acceleration though. Likely there's not great airflow under that big heavy body as well, that probably doesn't help the heat either. I think what I will likely end up doing is putting on a heatsink and fan, and then just replacing this motor with something bigger once it breaks or melts. Maybe one of the 4082 Leopard motors or something, I'm not exactly sure.

 

[LibertyMKiii]

So I changed it down to a 15T pinion. After a good hard 6S bash, the motor temped at 170 F. I don't love the slight loss of speed and acceleration though. Likely there's not great airflow under that big heavy body as well, that probably doesn't help the heat either. I think what I will likely end up doing is putting on a heatsink and fan, and then just replacing this motor with something bigger once it breaks or melts. Maybe one of the 4082 Leopard motors or something, I'm not exactly sure.

That certainly is the problem. Once you get used to a vehicle with aggressive gearing you can never go "back".
A good fan setup is likely your best starting point. There are many here on this forum with good experience on what works and does not. My understanding so far is that the ones with plastic fan shrouds do not last long.

 

[Wraith405]

Alright guys, I picked up the Yeah Racing aluminum heatsink with twin tornado fans. Honestly, lack of airflow may have been the entire problem the whole time. After 2 6S packs in a row, with 60F ambient temps, the motor was only at ~130F. That kind blows me away, I didn't expect the fan and heatsink to do anywhere near that much.

I'm going to gear back up to the 16T pinion next weekend and see how that goes! Hopefully the heat is easily manageable still. One other thing I haven't noticed though, this truck does get my batteries a little hot (120+), and I'm noticing some very minor swelling. So I'll have to keep an eye on that.

 

[olds97_lss]

My 3S HRB 5000mah 50C packs get warmer on my trucks than my Hobbystar 6200mah 50C packs. Guessing they are running at near their limit. I like them though as they are lighter than the 6200's. Costs me a 3-5 minutes of run time. I get 20-24 vs 25-30 with the 6200's.

 

[Surchaufeur]

??

 

[Wraith405]

Alright guys, things are looking good for the Mojave from this point. Here's the data from yesterday's bash. I did move back up to the 16T pinion and I think it's going to be fine on 6S with the Yeah Racing Heatsink and fan. I think the issue from before was just lack of airflow due to body shape so the motor just never cooled down any.

I ran 2 6000mah 6S packs through and the motor once again topped out at around 130 F. This was with 71 F ambient temperature. Honestly, I think you could safely go up another tooth on the pinion for even more craziness. I don't think that's a good idea for me though, my batteries were really warm (115-125 F). I think with SMC true spec or the Turnigy graphene 75C ones you'd be fine. I need to get a few more 6S packs for sure.

One bad part of the day though, I stripped some sort of diff gear in my Kraton. I have a terrifying grinding noise under hard acceleration or braking. That's the first sign of any diff trouble that I've had with it.

 

[SrC]

What are your ESC settings at. Specifically Punch???

 

[Wraith405]

What are your ESC settings at. Specifically Punch???

Still completely stock ESC settings.

 

[Notoriousone]

Still completely stock ESC settings.
[/QUOTE
Change punch to 5 or 6 if the temps are down using the 16t pinion, and see what that does.. I think the Mojave is on the edge of being just a bit too big for the Blx185 so a higher punch should help, but esc temps could go up as well

 

[birgy85]

Alright guys, I picked up the Yeah Racing aluminum heatsink with twin tornado fans. Honestly, lack of airflow may have been the entire problem the whole time. After 2 6S packs in a row, with 60F ambient temps, the motor was only at ~130F. That kind blows me away, I didn't expect the fan and heatsink to do anywhere near that much.

I'm going to gear back up to the 16T pinion next weekend and see how that goes! Hopefully the heat is easily manageable still. One other thing I haven't noticed though, this truck does get my batteries a little hot (120+), and I'm noticing some very minor swelling. So I'll have to keep an eye on that.

How did you plug in the two yeah racing fans? I can’t get mine to work! ?

 

[jkflow]

The connectors are marked, the positive(+) goes to the middle pin, the negative (-) to one of the outside ones. If it doesn't work use the other outside pin. Might be hard to see as it's grey on black.
These fans will not work if plugged in with reversed polarity (at least mine didn't).

 

[birgy85]

The connectors are marked, the positive(+) goes to the middle pin, the negative (-) to one of the outside ones. If it doesn't work use the other outside pin. Might be hard to see as it's grey on black.
These fans will not work if plugged in with reversed polarity (at least mine didn't).

Dude you’re the poop I finally got them working!?

 

[T3xasb3ast903]

Just get you a set of yeah yeah racing twin turbo fans... No more thermal ???

 

[Mojaveman]

Just get you a set of yeah yeah racing twin turbo fans... No more thermal ???

do you have a link for these fans please

re: yeah yeah racing twin turbo fans