My MM ESC gets hot - RC-Monster Forums

Robert · **My MM ESC gets hot -** 11.28.2008, 12:15 PM

I'm running 3s in a slash. The esc is the MM. Motor is Castles 5700. Gearing is 16/90. I also run castles BEC. The track is real small sandy oval. It's very very rare I get to open it up and punch it. I'm mostly at about 1/3 throttle but, the ESC gets hot and sometimes thermals on me. What do you guys suggest? Average temp on the ESC is about 170f.

lincpimp · 11.28.2008, 12:27 PM

Part throttle use will heat up an esc more than full throttle. I would suggest gearing down, but I doubt that will work. Maybe a much lower kv motor, like the 4600 or the taxxas vxl 3500kv motor. Sounds like your track is so small that the stock titan motor would be fine.

Robert · 11.28.2008, 12:35 PM

I have a vxl sitting around. I'll give that a try today.

lincpimp · 11.28.2008, 02:00 PM

Quote:

Originally Posted by Robert

I have a vxl sitting around. I'll give that a try today.

Sounds good, stick with the same gearing, and your speed will be reduced, hopefully closer to what you need for the track you run on.

BL_RV0 · 11.28.2008, 02:02 PM

Yes.

Dadx2mj · 11.28.2008, 02:30 PM

If you are sure all connections are good and there is no binding in the drive line why not put a small fan on the ESC? I did this during the summer when my Mamba Max was getting up to around 160º and since then it has never ran over 110º.

suicideneil · 11.28.2008, 03:01 PM

Given that its winter and his esc is thermalling, I doubt a small fan will help too much- that only cures the symptoms, not the underlying issue. I'd ask what the motor temps were also when the esc was running that hot or thermalling.

Dadx2mj · 03:15 PM

Quote:

Originally Posted by suicideneil

Given that its winter and his esc is thermalling, I doubt a small fan will help too much- that only cures the symptoms, not the underlying issue. I'd ask what the motor temps were also when the esc was running that hot or thermalling.

I agree putting a fan on can only be like putting a band aid on a chain saw wound. That is why I mentioned making sure all connections were good and there was no binding. I tend to forget about it being winter since I am in So Cal and still going out to run in shorts and T shirts.

Just thinking it could just be the part throttle driving and track conditions leading to the heat issue. If all else with the truck is as it should be the fan MIGHT be the answer, or at least worth considering

suicideneil · 11.28.2008, 03:35 PM

Not really. Part throttle driving is most likely to blame, therefore he needs a motor that is slower (lower kv rating) and will allow him to use much more throttle, without being too fast overall (which his current setup is). A lower kv motor on the same voltage and gearing as Linc suggested is ideal, or a mixture of lower kv and lower voltage- depends just how small this track is, but adding a fan to an overworked esc is never the best solution, when the real one is a change of setup. I/we only ever suggest fans for the MM when its being used outside of spec, that is, in a heavy MT or truggy and on 4s lipo- thats when the extra fan and a capacitor come into play.

Checking the wiring and gear mesh over is always a good idea though.

Dadx2mj · 11.28.2008, 10:21 PM

Okay well Robert says he has a 3500kv motor to try so I guess time will tell. I have run both the 3500 and 5700 on my Mamba Max and when geared to run about the same speed they both ran very close to the same temp as did the ESC. Truth be told I have never had my ESC hot enough to thermal but I am not sure the 3500 will make the ESC run that much cooler than the 5700 will. I honestly think there is some other issue be it a bind or a bad bearing or who knows what but if it is just the track or driving conditions and he still has heat issues with the 3500 and is positive there are no other issues is the fan really a bad idea?

11.29.2008, 01:22 AM

Just use a fan. There is no reason you should change to a lower kv motor when the esc can handle much higher kv motors. It's gonna get hot, there's probably little to no airflow getting to your esc. If putting a fan on it is a bandaid fix, then they shouldn't be coupling 5700 motors with the esc and selling them to the offroad guys. I'd personally disable your punch control, set your motor timing to the lowest, and set your start power to high if you can use throttle control to overcome all this. And I'd use a fan. Or, you could throw away a perfectly good motor and spend more money on a slower motor like everyone else suggests.

I just don't see why everyone's so quick to have someone else change major pieces of hardware and not let them run what they want. A $5 fan will do wonders on a mamba esc. It did with mine, although I've never had the luxury of experiencing a thermal shutdown, it kept runnin deep into the 200s. And how is providing extra cooling/airflow a bandaid fix? Should I use less fans in my computer because maybe running 3ghz is the underlying cause of all this heat and I should toss that and get a pentium 2 with mmx? That'll run cooler and not require so much cooling.

Not trying to sound like an A$$ or anything, and I really know far less about r/c stuff than the vast majority, but my point is, if you go out and buy a 5700, which btw is probably the highest recommended offroad 10th scale motor I've seen, and you want to run it in your slash, the esc gets too hot and cuts out, don't you think maybe it just needs a little more air and since you say runing partial throttle is causing the heat and he doesn't have a chance to open her up. Then a fan would probably be ideal, because he already owns a 5700 (and yes in this partiuclar case a velineon, which is besides the point), can't open it up enough to keep it cool, a fan seems like a cheap fix that will protect your electronics from overheating, the esc can take the abuse! Just my $1.05

Dadx2mj · 11.29.2008, 01:40 AM

DOH the settings in Castle Link never even crossed my mind. I know running the drag brake tends to play havoc with my temps.

11.29.2008, 01:49 AM

Yeah, and make sure you're up to date as well, forgot to mention that. And check your drag like dad mentioned, make sure you're not set too high.

lincpimp · 11.29.2008, 01:53 AM

Quote:

Originally Posted by 1maxdude

Just use a fan. There is no reason you should change to a lower kv motor when the esc can handle much higher kv motors. It's gonna get hot, there's probably little to no airflow getting to your esc. If putting a fan on it is a bandaid fix, then they shouldn't be coupling 5700 motors with the esc and selling them to the offroad guys. I'd personally disable your punch control, set your motor timing to the lowest, and set your start power to high if you can use throttle control to overcome all this. And I'd use a fan. Or, you could throw away a perfectly good motor and spend more money on a slower motor like everyone else suggests.

I just don't see why everyone's so quick to have someone else change major pieces of hardware and not let them run what they want. A $5 fan will do wonders on a mamba esc. It did with mine, although I've never had the luxury of experiencing a thermal shutdown, it kept runnin deep into the 200s. And how is providing extra cooling/airflow a bandaid fix? Should I use less fans in my computer because maybe running 3ghz is the underlying cause of all this heat and I should toss that and get a pentium 2 with mmx? That'll run cooler and not require so much cooling.

Not trying to sound like an A$$ or anything, and I really know far less about r/c stuff than the vast majority, but my point is, if you go out and buy a 5700, which btw is probably the highest recommended offroad 10th scale motor I've seen, and you want to run it in your slash, the esc gets too hot and cuts out, don't you think maybe it just needs a little more air and since you say runing partial throttle is causing the heat and he doesn't have a chance to open her up. Then a fan would probably be ideal, because he already owns a 5700 (and yes in this partiuclar case a velineon, which is besides the point), can't open it up enough to keep it cool, a fan seems like a cheap fix that will protect your electronics from overheating, the esc can take the abuse! Just my $1.05

Well, he asked what to do to stop the esc heat. A fan will do that. But it will not help the overall effecientcy of the setup. Swapping in a lower kv motor is not a huge expense. Plus he can sell the other motor, or keep it if he wants a higher speed option for bashing/fun. The esc will live longer if the setup is capable of using the entire throttle range. Those fets will only switch so many times before they wear out, no getting around that.

And the fact he has another motor is not beside the point, it is a free fix for him, even cheaper than a fan... Plus what happens when (not if) the fan breaks and he continues to run the setup hot. The esc will thermal, and that will not help it live longer.

The 5700 combo is a good 2S setup for off road. It is capable of 3s, but not optimum. If someone is using a setup in a less than optimum way and has a problem, we are only trying to help him out. I would go to 2s with that setup, or a lower kv motor. He has the vxl motor so problem solved to me.

You computer analogy is poor. Computers use fans cause they have to, much like air conditioners. They are designed around forced air cooling. Plus computer fans do not have to deal with dirt, mud, and excessive vibrations/shocks. And why would anyone who is serious with electric rc want to add any more moving complexity? That would be dumb.

I am not trying to sounds like an ass either, but we are just here to help. If you tried to run an 8000kv 180 motor on 6s lipo in a 1/5 scale truck and gear for 60mph I would let you know that you wasted a bunch of money on gear. That is why it is always a good idea to ask before you buy. Most setups you can think of have been tested here, so use the knowledge!!!!

11.29.2008, 04:31 AM

Ok, in my case of using a 6900 on 3s in a rustler doin speed runs, a fan did wonders for me. It just seems like everyone was quick to offer more complex advice like changing motors rather than verifying there isn't any locked up bearings, the esc is seeing airflow which it does in fact need, and stuff like that.