why are my temps so high???

[VintageMA]

Originally Posted by mk351e

a VERY trusted source told me that this setup would be ideal, as Neu motors love to spin, and running mine at nearly 50k is a non issue. While they're rated to go to 60k, they can typically function up to about 100k(!).

Is your source a helicopter or plane person?

While it is true that they operate very well at higher rpms - this is probably more true in models where they will spin to that RPM and gnerally just stay there (like a heli where the head speed stays pretty constant once the model is in flight). They will also pull goobs of Amps to get there starting off.

Take a read through some heli threads - these guys use 10-12S setups and can pull 15C constantly for the length of the run. They will heat up and fry motors faster than us - and their flight time is usually under 10 minutes.

A motor configured to spin up to 50k+ rpms will draw as much power as it possibly can to get there as fast as it possibly can - thus heat. If you do this over and over - acclerate/brake/accelerate/brake/accelerate/etc...... - you will definitely heat things up fast. And - IMO even if you gear down to normal speeds to reduce the load on the motor you could potentially be running the motor too unloaded and then again - in-efficient motor and more heat.

Take a look at what BrianG said as that makes a lot of sense (for normal running - speed runs are another story as Finnster and jhautz said). A nitro motor generally max's out around 30-35k rpm, spec your ride for 35-40k rpm (I've been re-configuring everything I have to be in the 38-40k rpm range) and with stock gearing (for that model) you will be 10-20% faster than the nitro version - gear down and you can go faster.

[mk351e]

final piece of the puzzle: the source was CC tech support. Not sure who it was that I spoke to, this conversation took place in may. Come to think of it, I'm not sure why I didn't just come out with that in the first place.

[lincpimp]

Originally Posted by mk351e

a little more info is in order I think:

1st - and this may be odd, but the battery is always dead last to get hot; in fact, it normally doesn't. It's usually, MMM, Neu, then battery gets hot. My MMM fan seems to be on almost all the time, but castle says it's ok. As for the motor selection, here's some interesting info: a VERY trusted source told me that this setup would be ideal, as Neu motors love to spin, and running mine at nearly 50k is a non issue. While they're rated to go to 60k, they can typically function up to about 100k(!). I just wanted to add a little fuel to my pending lipo fire here

Also, I didn't make my point right; i certainly notice a difference in performance between my 2 pinions: the 18T obviously has more top end, but it also seems to pull wheelies easier! What I meant was that there isn't much difference in temps between the 2 pinions.

Does this change anything? And does anyone know where I can get tires that can stand this horribly painful abuse?

Did you read any of my posts? Gear it down some and see what happens...

[RC-Monster Mike]

Originally Posted by mk351e

a little more info is in order I think:

1st - and this may be odd, but the battery is always dead last to get hot; in fact, it normally doesn't. It's usually, MMM, Neu, then battery gets hot. My MMM fan seems to be on almost all the time, but castle says it's ok. As for the motor selection, here's some interesting info: a VERY trusted source told me that this setup would be ideal, as Neu motors love to spin, and running mine at nearly 50k is a non issue. While they're rated to go to 60k, they can typically function up to about 100k(!). I just wanted to add a little fuel to my pending lipo fire here

Also, I didn't make my point right; i certainly notice a difference in performance between my 2 pinions: the 18T obviously has more top end, but it also seems to pull wheelies easier! What I meant was that there isn't much difference in temps between the 2 pinions.

Does this change anything? And does anyone know where I can get tires that can stand this horribly painful abuse?

If your VERY trusted source suggests that this setp would be ideal, then i would suggest that a reconsideration of the level of trust you give this person be adjusted a bit(no offense or disrespect to your source, but your setup is NOT ideal IMO - your temps tell the story, don't they?). The fact is, the 1515/1y motor will operate fine on 6s, but I wouldn't do it myself - your results are about what I would expect. Does it work - sure - but it ISN'T ideal IMO opinion (perhaps I am also a trusted source?). I could get 60mph out of a nitro motor, too - just lean it way out! I wouldn't expect it to last long or run cool, though. The 1515/1y is great on 4s and 5s for sure. On 6s, it is amp-hungry. When you run things on the extreme side, you can expect exactly what you are experiencing. :)

The 18t pinion calculates to around 90mph! - this simply isn't realistic and should not be recommended for anything besides a speed run - and even this is pushing it. To put things into perspective, I run a 1515/2.5d motor on 5s in my race truck(yes, a slower motor with lower voltage). This is on the mild side, but it will still outperform the nitros at the track pretty easily. Perhaps of interest to you is the fact that I can run this setup INDEFINATELY without heat buildup on the race track. As long as I have batteries to feed it, it won't overheat.
I would heed the advice already given here - reduce your input voltage or your gearing to reduce your heat. Just trying to help you get maximum enjoyment from the hobby. It sounds like you are having a blast with the sick setup you have, but you may not notice much of a performance decrease when making the suggested adjustments - but you will almost certainly be allowed to enjoy it for longer periods of time without fear of overheating. :)

[suicideneil]

Figures- I doubt they have any idea about your specifc setup and the gearing requirements to get sensible speeds on 6s lipo, just said "yep, our motors are the best, spin it fast as you like" and didnt think any more about it...

[RC-Monster Mike]

Agreed. I'm sure Castle Tech support is full of general knowledge on their products, but they are not likely to be nearly as experienced in the "specifics" of the various vehicles, gearing and setup nuances. :)

[mk351e]

I dunno. All I know is that every time I think I have this whole brushless thing figured out, I realize I know nothing. Kinda sucks, but it still beats nitro; and not only can I not afford to give up, but I refuse to! Things do seem to keep going wrong though. I completely craked a wheel and a shock tower yesterday, and I really do have to reglue all my tires and wheels after each day. Man is that getting old!

FWIW, I DID go over my entire setup with the guy, and he was definitely an older guy, with knowlege. He seemed to know quite a bit actually. I know you guys do too, so when a newbie comes along (like me), and gets different opinions, well, it makes it real hard to figure out who to go with. So, I'm gonna go back to 12T, see how hot things get, see if brake usage makes any difference (if so I'll go to mechanical brakes), and stay off the grass. If it's still too hot, then a new spur, and if THAT doesn't help, then there's a Neu motor for sale. I hope to not have to do that - major PITA (the lower kv's are still on backorder).

[jhautz]

If you cant trust what Mike is telling you, who can you trust?

If you are litterally blowing the tires off the wheels every time you run you are certainly generating alot of power. Yes the balisic power is fun, but these trucks can only handle so much. I used to run my stuff set up for crazy power too. But in the long run found much more enjoyment from a setup that ran within the limits of the equipment. Much more up-time on the truck when you arent pushing it beyond its limits. (cheaper on the reair parts bill as well.)

Dont get me wrong, im not saying you cant run a setup with a ton of power, it just sounds like you need to back off a little bit in general for the health of everthing involved. The brushless system as well as the truck.

[mk351e]

I DO trust and even like Mike, but shouldn't I trust CC too? I mean, when you call Neu, they even tell you to call CC for everything, b/c they're the distributor! I also trust the people on this board (especially briang and lincpimp who always seem to respond to my posts - thanks guys!), but when views differ, my head spins, escpecially since I really have no idea what the hell is going on! Maybe Mike IS more accurate; I sure don't know. I think when I picked out my components, I also leaned more towards what CC said, instead of everyone else here. I admit it; I thought you guys were being a little too conservative for me. I was wrong. Crap.

I do agree with everything you said though jhautz. The power IS addictive, BUT, I just cannot keep the front end on the ground no matter what i do w/ the 18T pinion, and I cannot keep the tires on the rims no matter what I do (DEAD SERIOUS, I'm starting to get high from ca glue!!), and I know things are gonna get shredded soon. Seriously, top speed is not possible, the front end just comes up! Also, I really want a cool running, tough as nails reliable BL system - it was the whole point of getting out of nitro - no more worries, just turn it on and run until the battery dies. I don't want to be checking temps every minute anymore.

[tc3_racer_001]

would a step down to 4s be too much? that would surely tame those wheelies and temperatures. that is, until you are running WOT constantly and heating up the batteries too much. in the end i think everyone wants a super powerful reliable truck to the point of being ALMOST uncontrollable, to have the ability to slaughter the nitros in the parking lot, but then be able to race seriously without flipping every turn...?

[Mozzy]

Is there anyone on here that has been running the same car as mk351e with a set up that doesn't over heat?

At least this way mk351e will see what works with others & understand a little more of his own set up & it's capabilities.

Now, when I was running my CRT with a Neu 2700, MM & 4S 6000mAh, 13t pinion everything else stock, the car would absolutely fly.
No wheelies at all & I was/am running a torsen centre diff (basically it's a locked diff when the front loses traction & makes it 50/50 split.)
It was blindingly fast, but(!), everything but the batteries ran cool.

By the end of the run the battery would be nudging 85 degrees C(!) on a coldish 15 degree C day with a runtime of a mere 5mins 50secs (I timed it).

How would reducing current help mk351e's temp probs?
I don't get some of this stuff at the best of times, so, this just makes it more confusing.

I'll be working for my friend now who's currently in Tawain, HK & China, securing contracts with companies to supply components for everything from nitro to BL.

I've also got alot of guy's interested in BL conversions, but, I'm at this stage limited with knowledge to be able to say, you need this, this, this & this & you'd be able to run reliably from day one for this purpose. Obviously, the setup & requirement of the person's use would vary & therefore so would the set up.

I treat you guy's like an encyclopedia of the BL world as I know it. I listen/read everyone's input then generally go for the most common answer. Thanks.

By the way, so far after my op I'm doing alright, very sore after have them saw through my sternum. I'll post pics of the clots that were removed from my lungs after the 12th Sept when I get back to Melbourne, I know you'll all be saying holy crap, cause, I certainly did! Just happy to be alive at this stage.

Long live BL & me!!

[bdebde]

Originally Posted by Mozzy

Is there anyone on here that has been running the same car as mk351e with a set up that doesn't over heat?...

I run a 12lb Muggy on 6s with a Neu 1515 2.5D/F. I was running 12/48 gearing (just under 40mph) with no heat problems (150 motor 140 esc) with MGM 16024. I have geared up to 13/48 (a bit over 40mph) to give the new MMM a workout, still no heat problems (150 or so on motor and esc).

I run 40 series bowties, which save about half a pound of rotating mass and are a bit smaller diameter than stock. But I even tried some larger tires than stock (and about a half pound heavier), without much rise in heat; although the "punch" was noticably missing with that set up.

I have tried a higher kv motor (similar kv to 1515 1Y), a Plettenberg big max; but results were not good. MGM ESC would thermal if running for long as well as batteries getting hot, and ending with a demagnetized rotor. A lower kv motor would be the best bet IMO. I am quite happy with my 2.5D set up, it has plenty of power and runs forever without overheating. I may be able to get a bit more speed with higher capacity (or higher C) batteries, but it is fast enough for me now. I considered a 1521 1Y, but Mike had none in stock at the time I ordered the motor, that may be the way to go if you need more speed.

[Just go Play]

It seems as though many people that are running the tekno neu motors are seeing higher temps then the original neu motors tend to run at. This may or may not be the case for everyone...idk.

As for the voltage that your battery cuts off at it sounds like you are actually over discharging it. If the resting voltage is 20v that is less then 3.4vpc which means that when under a load your voltage is likely dropping well below 3vpc.

FWIW: my 1Y seems to like 5s in a @10lb. vehicle and runs noticeably higher temps in a 14.5lb vehicle with larger heavier tires. It is capable of running reliably in the heavier vehicle, just not at the same speeds for the same lengths of time.

If you can't keep the front end on the ground all that power is not doing you much good. You may as well drop some voltage and get your temps down and the power at a level that is more usable.

[RC-Monster Mike]

"FWIW, I DID go over my entire setup with the guy, and he was definitely an older guy, with knowlege. He seemed to know quite a bit actually. I know you guys do too, so when a newbie comes along (like me), and gets different opinions, well, it makes it real hard to figure out who to go with. So, I'm gonna go back to 12T, see how hot things get, see if brake usage makes any difference (if so I'll go to mechanical brakes), and stay off the grass. If it's still too hot, then a new spur, and if THAT doesn't help, then there's a Neu motor for sale. I hope to not have to do that - major PITA (the lower kv's are still on backorder)."

My father is an older guy, too - but I wouldn't ask him for setup advice.
As I said, I am sure the tech guys have a good handle on things at CC, but I doubt they have the same depth of knowledge and experience as some folks here and the setup "works". Proper gearing will help, and switching to a lighter tire/wheel combo will make a huge difference in this particular setup.

Originally Posted by mk351e

I DO trust and even like Mike, but shouldn't I trust CC too? I mean, when you call Neu, they even tell you to call CC for everything, b/c they're the distributor! I also trust the people on this board (especially briang and lincpimp who always seem to respond to my posts - thanks guys!), but when views differ, my head spins, escpecially since I really have no idea what the hell is going on! Maybe Mike IS more accurate; I sure don't know. I think when I picked out my components, I also leaned more towards what CC said, instead of everyone else here. I admit it; I thought you guys were being a little too conservative for me. I was wrong. Crap.

I do agree with everything you said though jhautz. The power IS addictive, BUT, I just cannot keep the front end on the ground no matter what i do w/ the 18T pinion, and I cannot keep the tires on the rims no matter what I do (DEAD SERIOUS, I'm starting to get high from ca glue!!), and I know things are gonna get shredded soon. Seriously, top speed is not possible, the front end just comes up! Also, I really want a cool running, tough as nails reliable BL system - it was the whole point of getting out of nitro - no more worries, just turn it on and run until the battery dies. I don't want to be checking temps every minute anymore.

No reason not to trust CC but the fact is, some members here(myself included of course) have run brushless setups in cars and trucks for twice as long as CC has even offered car controllers. Lets face it - you took our advice and CC's advice and listened to what you wanted to hear in some respects. Human nature I suppose, but you wanted to trust what the CC tech said because it was in line with what you wanted to do - everyone probably does it to a degree.
Before CC was the distributor, there was DMA - when someone asked them for car setup advice, it was directed to me - the car/truck expert if you will. Not that I need any more email volume, mind you - but these forums are a wealth of accumulated knowledge. Oh, and I like you too.

[Finnster]

The big part of the problem is you are running monsterous power. A 1Y on 6S, I'm sure you are seeing 2500-3000W+, esp if you are running 40series tires (IDK.)

HUUUUUUUGGGGEEE power.

Even @90% odd efficiency, that's still as much as 300W of waste heat. That's a ton. You need to:
A.) Bring power down w/o killing eff%
B.) Get a more eff motor/setup
and/or
C.) Get a motor that can dissipate more heat

Perhaps a 1521 may be more appropriate for what you are wanting to do. Drop the kvs a lot and have a bigger can to withstand more heat. Ups eff% too. Do you really need/want all that power?

If you can bring eff up several %, you can run that much more power w/o the waste heat. Combine that for w/ a bigger can for a much cooler setup.

Else drop power into the 1700-2200W range where the 1515s are much better suited for.

What is your goal?