Over heating motor after battery upgrade

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BHawthfl

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My boys both have the ecx ruckus. For there birthday I got them both a 8.4v NIMH battery's. The stock battery was 7.2v. After installing and driving for a few minutes both rc trucks smelt like wire melting and motors were to hot to touch. The motor is a 15T. I think I need to buy heavier 15T motors to correct over heating of bigger batteries? Also is it a good time to go brushless while doing a motor swap? Does anybody suggest a heavier 15T motor that I should check into buying? Thanks for the help
 
You may just need to change your gearing to give it a little more top speed. By increasing voltage you increased the power to the motor so it may just be overheating because it is maxing out the gearing.
 
So when you say change the gearing, are you talking like going to a 13T motor?
 
You will need to change the the pinion spur gear combo, it's been along time since I have done it on an electric vehicle I have just been running stock gearing on my Yeti. Here is guide from Team Associated basically you may need to gear taller to release some of the extra power you are now putting on the motor due to the increased voltage.
https://www.teamassociated.com/pdf/cars_and_trucks/shared/gear_ratios.pdf
 
I'll try that. Thanks for the help. Much appreciated
 
Not to contradict, but being a stock brushed motor, I'd gear it down. Meaning I'd go one or two teeth less on the pinion, for more low end. Especially if you're doing typical monster truck bash type stuff, like running in the grass. Not sure how old your boys are, but my kids just pin the throttle open. I had to drop 2 teeth on my Stampede for them. And my middle boy, I had to do all kinds of gearing on his Duratrax because it has a weaker motor.
 
I agree with the pinion gear decrease. This is what I started by doing. I bought a 12T traxxz motor for trying the bigger gauge wire plus to grab more of the bottom end and stop the overheating. I did have to grind down the motor shaft so that it wasn't to long and hit pinion cover. I've only run it a couple times since the install and no overheating problem..
 
Not to contradict, but being a stock brushed motor, I'd gear it down. Meaning I'd go one or two teeth less on the pinion, for more low end. Especially if you're doing typical monster truck bash type stuff, like running in the grass. Not sure how old your boys are, but my kids just pin the throttle open. I had to drop 2 teeth on my Stampede for them. And my middle boy, I had to do all kinds of gearing on his Duratrax because it has a weaker motor.

Oh man how dare you contradict me I am the ultimate authority on electric rc let the flame war commence. :D

Just messing with you, it has been a long time since I messed with gearing, that was why I posted the link with the info. I couldn't remember the exact path to go down, glad you got it worked out. :thumbs-up:
 
@BHawthfl glad you got it sorted! Not sure if you know, but that Traxxas "12T" is a bit misleading. It's a 550 can (bigger) so it's about the same as your old 15T but will have a bit better low end grunt.
@griff7373 , hey! Gimme some cred, at least I made it "sound" like you knew what you meant. ;p

*edited on account of fat thumbs*
 
The link with the gear info was very helpful. I'm changing pinion gears tomorrow and start playing with that and figuring how that works. I am a little confused about 12t and 15t. I don't understand how dropping the number of revaluation helps me on top end so motor will cool off.. A 15t would have more top end at the same time a 12t would have more torque and bottom end right?
 
I guess I confused you. The traxxas Titan is a 12T 550 motor. So it has a physically larger can. If equates to a 15T 540 motor. 540 is the typical can size on a 10th scale rig. T stands for "turns". Fewer turns = more RPM. Fewer turns usually also = less torque.
 
Well I really appreciate all the help and advice. What a great group to be part of.
On the pinion I probably need to go more teeth to gain torque and decrease top end motor heat?
 
No lose teeth to gain a bit more torque, so the motor doesn't works so hard. Less work=less heat. I know this works, because I ended up having to do it to my Revo VXL. It would overheat badly until I dropped a couple of teeth.
 
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