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Old 10-06-2005, 11:51 AM   #1
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Default Engine overheating: reasons?

Hi, i got a tf tc3 rtr, everything is stock from the box.
My engine is getting so hot, the soldering of the wires and caps melts!
What can be the reasons for this?
Idon't think that gearing has anything to do with this problem, since I don't think that the factory would send the wrong gears.
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Old 10-06-2005, 11:58 AM   #2
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First thing, Engines are gas powered, Motors are electric.

There could be a number of things that are causing this. Take the pinion rear off and spin the wheels. If they don't spin freely, you have something binding up the drive train and that needs to be fixed. Also, how long are you running the car and what motor is in it? How long are you waiting between runs?
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Old 10-06-2005, 12:37 PM   #3
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19T stock, running 1500mAh batts. I use this car to drift with pvc tyres(high power application with almost no airflow inside).
I use 2 bats almost in a row (wait the time to smoke a cigarette between batts). i do so 'cause I know ppl are running 3600mAh, which is like 2 batts.
Then I let cool the batts, recharge' em and let them cool down again b4 I run.
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Old 10-06-2005, 12:54 PM   #4
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First you need to let the motor cool between runs. Plus since you're drifting I assume you're pretty much on the throttle most of the time and as you said, no air moving under it to cool things down. That'll get a motor hot right there.

We use 3600 and 3800 batteries for racing but we still don't run more than 5 minutes and the motors are usually plenty warm by then. So it's not like running 2 batteries. The extra capacity lets us push how much power we're pulling from the motors. If you want to drift and be able to run for a long time, I suggest you get a Novak Brushless system.
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Old 10-06-2005, 01:18 PM   #5
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yes but on another site, where i didn't get any answer, people are using 3300mAh for drifting getting about 40 mins runs with 23T motors. how come they don t overheat the motor too?
And b\l is interesting, but way to powerfull for drifting, would have to program the esc to max at 50-60%.
Another question, what are the numbers on an esc(continue current 30amps, high current (30sec) 70amps, pike (5 sec) 120amp)?
is that the max the esc can handle or is that what it gives out?
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Old 10-06-2005, 01:34 PM   #6
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I'm not sure what numbers on an ESC you're talking about so I can't answer that one.

But were those guys who were getting 40 minutes of run time drifting?

One other thing that can make the motor get hot is wear. How long has it been since you've had the comm cut on it and new brushes put on it?
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Old 10-06-2005, 01:44 PM   #7
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the car is brand new, maybe 3-4 hrs, so i think wear is not really an issue here.
correct me if i'm wrong, but changing the brushes is done about every 10 hrs, but this when your racing, as a hobby use, about 30 hrs?
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Old 10-06-2005, 01:45 PM   #8
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Quote:
Originally Posted by milen
yes but on another site, where i didn't get any answer, people are using 3300mAh for drifting getting about 40 mins runs with 23T motors. how come they don t overheat the motor too?
And b\l is interesting, but way to powerfull for drifting, would have to program the esc to max at 50-60%.
Another question, what are the numbers on an esc(continue current 30amps, high current (30sec) 70amps, pike (5 sec) 120amp)?
is that the max the esc can handle or is that what it gives out?
Those are max ratings I assume.

Continuos Current: ESC can provide 30 Amps for longer periods of time.
High Current (Max): ESC can provide 70 Amps for only 30 secs MAX (before is is becomes toast)
Peak Current: Under the most severe loads ( great traction and full throttle; the ESC can only provide 120 Amps ( very short times; burst ).

Those seem to be standard notations in the electronics industry. BTW, those numbers seem rediculously large considering you guys only run 3 - 6 amps packs...Hhhm.
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Old 10-06-2005, 01:59 PM   #9
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Quote:
Originally Posted by JAG Racing
Those are max ratings I assume.

Continuos Current: ESC can provide 30 Amps for longer periods of time.
High Current (Max): ESC can provide 70 Amps for only 30 secs MAX (before is is becomes toast)
Peak Current: Under the most severe loads ( great traction and full throttle; the ESC can only provide 120 Amps ( very short times; burst ).

Those seem to be standard notations in the electronics industry. BTW, those numbers seem rediculously large considering you guys only run 3 - 6 amps packs...Hhhm.

Asking cause i think i read somewhere that they were the currents the esc gives, NOT max.
When u press the gas, it would give u 120 amp 4 1 sec, then give 70 amps for 30 sec, then keep going at 30 amps.
I can understand it, to take off from a stillstand like a bullet.
what do u think about it, anyways in my opinins they are max ratings, but just to kill a doubt!
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Old 10-06-2005, 02:00 PM   #10
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Quote:
Originally Posted by milen
the car is brand new, maybe 3-4 hrs, so i think wear is not really an issue here.
correct me if i'm wrong, but changing the brushes is done about every 10 hrs, but this when your racing, as a hobby use, about 30 hrs?
What I meant was wear on the motor. When I race 19 turn, I cut the com and change the brushes every run. (5 minutes) During practice I'll let it go 2 runs. 10 hours of running on a set of brushes is unheard of. That's 120 5 minute runs. No brush in the world can handle that. Let alone 30 hours. Pull the motor out and look at the brushes and the com. If they're discolored (red, black, or if it got really hot it'll be white) then the com needs trued and the brushes need replaced. If the brushes are less than 2/3 their length when new, they need to be replaced. The more often you maintain your motor, the longer it will last. If you've gone as long as you say without a cut com, the motor is probably beyond gone and will need to be replaced.
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Old 10-06-2005, 02:10 PM   #11
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Quote:
Originally Posted by milen
Asking cause i think i read somewhere that they were the currents the esc gives, NOT max.
When u press the gas, it would give u 120 amp 4 1 sec, then give 70 amps for 30 sec, then keep going at 30 amps.
I can understand it, to take off from a stillstand like a bullet.
what do u think about it, anyways in my opinins they are max ratings, but just to kill a doubt!
No, the speed control provides the necessary current that the motor needs depending on your throttle position and the load . The battery packs are the current sources and the ESC simply regulates the amount of current to the motor under variable loads. Those should be max ratings. Transistors can only handle so much current before they blow.
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Old 10-06-2005, 02:29 PM   #12
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Something else to consider. You mentioned RTR, so in those cases, they usually come with low silver brushes and are designed to be run right out of the box. They aren't really meant for serious racing, so overheating shouldn't happen especially since you are drfiting and that usually is easier on the motor since there is less resistance (for the most part). It sounds like you may be generating friction some where else. The motor will get hot, but not so hot that you melt solder. Remove the pinion and check the drive train for any unusual friction. Without a motor attached a TC3 should spin it's drivetrain fairly freely.
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Old 10-06-2005, 04:03 PM   #13
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i just checked my motor, brushes are about 1 cm long (a bit longer), have no discoloration whatsoever, and the motor is sealed, so i don t know how to get to the comm.
let's say i want to run it cheaply, when do i HAVE to change the brushes?
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Old 10-06-2005, 04:12 PM   #14
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In all honesty, if you want long term cheap, buy a brushless. It's pricey up front but there's no motor maintenance at all. Novak has a "Stock Motor" for their brushless that has similar power to a normal stock motor.
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Old 10-06-2005, 04:21 PM   #15
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Things to check:
-GEAR MESH? IF way to tight and in a RTR its totally possible that it came to tight out of the box or you messed with it to make it to tight. This will eat run time and overheat a motor. Should be some backlash between the pinion and spur gear

-Drifting usually means slow speeds but lots of full throttle. You will heat up a motor that way.

-The 19T motor in included in the TC3 is a POS. Thats a given. Most RTR included motors are POS. So what i would suggest is going to a 27turn stock motor. 9times out of 10 these tuned stockers will smoke most 19t and 15t rtr motors. and do so at much lower temps. Breaking PVC loose for drifting wont take to much power

-run time with 3600s and a 23T as your friends run can be quite long. 45minutes? Probably not but 10 minutes plus would not be unreal

-motor rebuilding. For the backyard basher/drifter your not gonna need the upkeep we racers do.. but because your likely outdoors the chances of pulling in dirt and crap into your motors is higher (we normally run on carpet or very clean preped parking lots or tracks). Even a low milage motor can turn to SH$% in no time if you fly around dirty lots. A good practice for a basher would be to get a comm stick and some motor cleaner to do a flush out and light cleaning of the comm and brush faces after a day of running. Always re-lube the bearings or bushings after. You should not install new brushes ever without getting the com cut. In most cases you will eat up the new brushes very fast and damage the comm even more. Cut then brush only.

-GEARING i notice many drifters neglect to take that into consideration. I saw a drift car at my LHS ready for motor rebuild the other day. The pinion was the largest one i had ever seen!!! No wonder the thing needed service. Try to run the smallest pinion you can and gear up till you getting no more usable speed. Large pinions will overheat a motor and takeaway low end grunt needed to break loose the car..

hope this helps (ps i hate drifting )
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