Tedward

Hello everyone, I'm just starting the hobby with a xxx SCT that a friend gave me. I've been running it a bit, but after 10-15 minutes the motor gets hot, 170+, the esc gets to at max 130, after stalking the forums I found that my motor may be too much to handle. Its a cms36-5700kv with sidewinder 1/10 ESC. Gearing is 20/86. The first time I ran it I chewed the teeth off the original green spur gear, and replaced it with the 86t. I don't race it (not yet at least) but would like to find out what a good gearing would be in order to save the motor and esc from thermal damage. I am running 25c 2s lipo 5000mah battery. Thanks in advance everyone.

collector1231

My Feedback: (1)

10-15 minutes is an accurate, even somewhat long, run time, and that motor is more than powerful enough to run that car. Does the car look/feel stiff?

RustyUs

Welcome to RCU Tedward.

I would start out be dropping down to a 15T pinion gear and recheck temps. The 5700kv is a handful. Possibly regaining some power (gearing down) will take some stress off the motor and cool it down a bit.

Tedward

The truck isn't very stiff, it corners tight and handles well, at least I think so.

As for pinion I'll pick one up and see how it works.

Thanks guys I appreciate it. I'll post after I change it out.

RustyUs

Having the proper gear mesh is very important to the longevity of the spur gear. Check out the video below. It's a little bit long to get the point across but was the first video that came up in Yahoo! search.
https://www.youtube.com/watch?time_continue=48&v=sKsDeedtIbA After you do it a few times, you'll be a pro at it, and won't need the paper. Every once and a while I still use the paper trick when motor is stubborn.

Tedward

Thank you

egbasher

I agree with Rusty. Drop the pinion down a tooth or two and see how the temps are. 130 on the ESC isn't bad but 170 on the motor is pushing it.

zackS30

If youre going to race then races are only 7 minutes long.
Also your battery has to do with it aswell. Get a battery with more punch like a 50C and it will perform better. the system is being some what syarved for power it gets hot bcuz its trying to hard with not enough energy being thrown at it.
Take it to a track and just do a practice set a timer for 8minutes to be safe and try to do the fastest laps you can then check temps. My motor when racing never went over 140* and my esc was pretty low like just into 100*
I also ran a 70c 2s saddle pack though.

Tedward

I havnt tried it out on a track yet, but am picking up a new pinion today, I will also look at batteries, I wasn't aware that this system needs a higher c rating. Will that also improve on performance? Top speed and excelleration?

EXT2Rob

My Feedback: (1)

C-ratings on LiPo packs are all over the place, and it's hard to know for sure if the number is realistic or not. Only experience tells the tale. For instance, most Traxxas packs are rated 20-25C, but in bench testing, they perform more like a 50C. Others may rate their packs at 50C, but they only perform like a 25C. Depends on the brand. Prices are all over too. Traxxas and Max Amps are the pricey-est. I prefer the Gens Ace and SMC brands. SMC is my fave, as you can GET them with Traxxas connectors already installed (my preferred connector) and the prices are unbeatable. Also the SMC packs use nice fat wires.

What you notice with a higher C pack is more mid-range "oomph". My older Gens Ace packs are 50C 5000mah, but when I put a SMC 7200mah 70C pack in my SCT with the big Novak Ballistic motor, it really lights up!

Tedward

With my battery (2s lipo 5000mah 35c) and ESC (sidewinder 1/10) would an XTM 3900kv 4 pole be better then the cm36 5700 in terms of run time and heat? As I'm not racing just out bashing I guess.

EXT2Rob

My Feedback: (1)

In general, yes.

egbasher

I'm not sure how the two motors you mention would compare in run time or heat. The 3900 kV 4 pole will have more torque than the Castle but will have a lower top speed than the 5700, assuming the same gearing. You'll have to get a bigger pinion if you're going from a 5700kV motor to a 3900. What brand battery do you have? A 35C should be adequate but as Rob said a larger C will perform better.

Tedward

Its a hobby people battery

RustyUs

That Castle Creations motor (5700kv) was my first brushless motor back in the day of racing a B4 buggy. All I can say is, I probably never got to use the full potential of that motor during a race. It's a great motor for 2wd buggies and trucks if you got the room to let 'er rip . I couldn't even imagine one on 3S LiPo power...yeah I could. Just go on YouTube.

Tedward

I geared down to 18/84 as the local shop didn't have anything smaller pinion wise. It still gets pretty hot, think I'm going to replace the bearings next. As I'm unsure of previous maintenance.

Carabidae

I switched my ESC/Motor on the firestorm with a MMP/5700.. after 2 runs, one on tarmac and one in the dunes, my spurs get mashed up everytime. I'm thinking of going back to my original setup.
But in both case, the 5700 never overheated, except for when i used the 35/77t gearing.
Also, since you got it used, i would check bearings, relube them.
As for batteries, i use nano tech for the 1/10 and A-specs on my 1/8 buggys.

Tedward

I have the older 2pole 5700, you running the 4pole 1406 5700?

Carabidae

yes sir the 4 pole 5700kv.
The motor that came with the kit is a 4000kv, i'll give the 5700 a last try tomorrow, if it eats up the spur, ill switch back to the 4000.

Tedward

I don't have an issue with chewing spurs, I've been debating on trying one of the castle 4pole motors

Carabidae

i would advise the 4600kv for a basher. I first got the 5700kv for my T3, then switched with the Firestorm setup. after today's dunes bashing, im going back to the 4000kv.

EXT2Rob

My Feedback: (1)

The Castle 4-pole motors are strong, made well, and use superior bearings. I opened my 5700kv to see if it was dirty inside, and to check the bearings. To my surprise, the inside of the can was completely clean! This, the first time opening it in four years! And, the bearings were in perfect shape, clean and smooth. I was impressed.

If you don't find anything binding that would account for the hot motor, and the gearing change doesn't help, the only alternative is to get a "fan-sink" for the motor. That's a heatsink with a fan on top. The heatsink helps draw the heat away from the motor, and the fan cools the heatsink, cooling both. They'll drop motor temps 10-15 Degrees. I got this one at Integy. Only $15, BUT, the fan itself SUCKS, a cheap piece of crap. You'll have to drop another $10 on a Novak 30mm fan. The Novak fans can take the dirty environment of off road racing.

Tedward

So I picked up a $60 exceed 1/10 truck off craigslist, it happened to have a sidewinder 3 and 4 pole castle 4600kv in it. I swapped out my 5700 and old ESC, night and day difference! Doesn't get hot anymore and I'm getting 25% more run time! Now to get a 3s lipo and see what it does! I also put the 20t pinion on it. Running smooth

EXT2Rob

My Feedback: (1)

Perfect!! And the Sidewinder 3 seems to be a better unit than its predecessor. Watch The Temperature when you run the 3S .

Tedward

Most definitely lol