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Old 05-31-2007, 05:52 PM   #1
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Default Help!!! I keep frying speed controlers - its getting expensive.

Long story short.......

I have a new T4 with a Futuba controler and reciever, 19t Pro (komoto dragon) motor tuned by High Velocity.

I have already fried a Duratrax speed controler that handles down to 8 turns, 2 weeks ago. Today I just fried a New Novak Rooster that can handle down to 12 turns.

The gearing is exactly to what the T4 manual says to do.

The Duratrax lasted 6 batteries of use on the track and the Rooster lasted 2 batteries on the street in front of my house.

The batteries were not used back to back either and every thing had enough time to cool.

What gives???
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Old 05-31-2007, 06:39 PM   #2
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what kind of batteries?
are you sure the ae manual didnt say suggestions?
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Old 05-31-2007, 06:45 PM   #3
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you might be gearing too high, or maybe something is wrong with the drivetrain, such as excessive drag.

try putting a smaller pinion gear on the motor, 2-4 teeth less.

and then inspect your truck. take the pinion gear off, and spin the wheels. they should roll freely. if there's a grinding, or if it doesnt stay spinning, than ther is something whrong with the drivetrain.

also, are you running 6 cells, or 7?

make sure the motor's in good condition too.

good luck!!!
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Old 05-31-2007, 07:17 PM   #4
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The only suggestions in the AE manual was the spur and pinion sizes which I did exactly what it suggested. The batteries are duratrax 4200 mAh nimh 6 cell pacs from Tower Hobbies.

The motor is new as well.

I also have a RC10T which is set up identicalrto the T4 that has a 10 turn double motor in it. I also run a CO 27 pro in that truck as well. The 10T was fully re done top to bottom and was completed just a couple of days after the T4 was built. They had identical electronics untill I replaced the first speed controler with the Novak. Except for the motors.

Is there any possibility that this motor can be causing them to fry?

I have not temped any thing with a thermometer, but none of the components seemed excessivly hot to the touch and though that isnt the correct way to do it, you can usually tell if something is way out of the norm.
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Old 05-31-2007, 07:30 PM   #5
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Quote:
Originally Posted by OG RC 10T
The only suggestions in the AE manual was the spur and pinion sizes which I did exactly what it suggested. The batteries are duratrax 4200 mAh nimh 6 cell pacs from Tower Hobbies.

The motor is new as well.

I also have a RC10T which is set up identicalrto the T4 that has a 10 turn double motor in it. I also run a CO 27 pro in that truck as well. The 10T was fully re done top to bottom and was completed just a couple of days after the T4 was built. They had identical electronics untill I replaced the first speed controler with the Novak. Except for the motors.

Is there any possibility that this motor can be causing them to fry?

I have not temped any thing with a thermometer, but none of the components seemed excessivly hot to the touch and though that isnt the correct way to do it, you can usually tell if something is way out of the norm.
i dont see why 2 speed controls would be fried with a 19 turn, but not with a 10 turn. it doesnt make sense.

just try a much smaller pinion, and make sure there is no drag.


and are you sure the esc's are frying? do they smell nasty? i cant smell through the internet, but i do know the burnt smell of silicon. it just doesnt smell good.

give us more info, and maybe we can fix this!
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Old 05-31-2007, 07:36 PM   #6
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The T4 manual recommends gears I never ever run. It recommends crazy big pinions. I think that gear chart was made when we ran NiCad batteries and much older tech motors that didn't turn any rpms.

The Komodo is a new motor that turns high rpms, which requires a smaller pinion, and 4200's have very high voltage, which requires a smaller pinion.

So gear way down from where you are the next time out.

If that doesn't work, theres something else wrong. Like a hub bearing is seized. Which is very common if you run in dusty conditions.
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Old 05-31-2007, 08:34 PM   #7
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I kind of doubt it's gearing, or the motor would be getting way hot. I've never had a speedo give out before a motor.

I would run through the speed control setup very carefully. Make sure your trim and end points are properly set as the speed control suggests before going through the setup process.

Also, are you running a Shottky diode? I don't think the Rooster has one built in like some Novaks.
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Old 05-31-2007, 09:27 PM   #8
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I doubt it's the gearing. The AE gearing is a little high for my taste, but I generally only gear down one tooth on the pinion, even with mod motors. If the speedo ran fine with the other motor, then my bet's on the new motor. Is it an aluminum endbell? You could be shorting out.

Somebody mentioned the Shottky diode. Do those speedos have reverse? Don't run a Shottky with a reversing speedo.
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Old 05-31-2007, 09:31 PM   #9
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Never use a Shottky diode with a reverse speed control! It will fry it very quickly.... ask me how I know, LOL!!
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Old 05-31-2007, 10:45 PM   #10
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Your gearing is either to high or low. Also make sure you don't pinch any wires. And don't solder anything backwards.
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Old 05-31-2007, 10:47 PM   #11
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Quote:
Originally Posted by glassdoctor
Never use a Shottky diode with a reverse speed control! It will fry it very quickly.... ask me how I know, LOL!!

Gee, just out of curiousity. How do you know?
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Old 05-31-2007, 11:20 PM   #12
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OG??? Youre name wouldn't be Jrod, Would it?
"Inside joke in colo."
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Old 06-01-2007, 12:12 AM   #13
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id have to go with gearing also. or for some crazy reason you dont have the speedo set up right.
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Old 06-01-2007, 07:25 AM   #14
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I havent used any of the diodes as per the instructions.

I know it dosnt make much sence? I mailed it back to Novak this morning and the other one to Duratrax last week. I will let you know what they say when I get either one of them back.

I will start temping everything to see what the Speed controler, motor and battery are running at.

Any ideas on what is a normal temp range for each of those?
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Old 06-01-2007, 03:11 PM   #15
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Sounds like a bad motor to me
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