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  1. #1
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    gravedigger - smoking motor

    Last week, we were running GD pretty hard - we ran through 2 battery packs (back to back---Traxxas 2941 Series 3 NiMH 7-Cell 8.4V 3300mAh Hump )

    towards then end of the 2nd battery cycle the motor blew some smoke and slowed right down. A week later it barely runs - so ya, pretty sure I blew the motor...

    I am not worried about replacing it, more concerned about how I blew it. Should I let it rest in between battery changes? for cool down?

    Are the batteries ok for what I am doing? Could a different battery run longer?

    Is it possible I did battery damage too?


    Forgive me if naive, it's all very new to me...

    thanks

  2. #2
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    I've never used a 7cell nimh so I'm not sure how much extra heat that causes, but when you get higher voltage batteries the motor heats up more, generally you need to regear lower to lower the temps.

    You might have hurt the batteries, but I'm really not sure. After the run how hot were they?
    1/16 Summit beadlocks with 2.2 rock lizards

  3. #3
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    pretty hot to touch, but it's not like I couldnt hold them. For short money I will replace motor (same titan 550 12 T) and see what happens..

    but looking forward, how would I learn about battery options and possible upgrading? I am sure there are plenty of RC guys running a lot longer and aggressive than me with much better systems.....I need to learn more about all...

    thanks

  4. #4
    RC Champion
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    Before you replace anything, buy an infrared thermometer. They are mandatory in this hobby. Monitor the motor and ESC temperature throughout your first battery pack-say at 5 minute intervals. If your motor is getting above 160F get smaller tooth pinion that was originally installed on the GD-19t I believe. Gearing down as it's called is the first defense against overheating motors. I would go with a 16t pinion if this is the case.

    Also, running in grass or sand puts more of a strain on the motor than say concrete or asphalt. More strain = higher temps. So a truck geared and running cool on the street will more than likely not run cool in grass.

    Not sure if the GD comes with a 'speed pinion' but if it does and you installed that, well then you have your answer. These pinions coupled with the 7-cell packs are used to reach the advertised speed of the models, but they are for speed runs, streets, etc. and they usually are the culprit of the burnt and smoking Titan motors.
    All those who believe psychokinesis raise my hand

  5. #5
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Is this a 16th Digger or a 10th Digger?
    Due to the battery you listed, I am thinking you may be in the wrong section of the forum...
    Whatever it is I just said... I could be wrong.

  6. #6
    RC Champion
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    Quote Originally Posted by Jimmie Neutron View Post
    Is this a 16th Digger or a 10th Digger?
    Due to the battery you listed, I am thinking you may be in the wrong section of the forum...
    7-cell battery would be the 1/10th scale. I missed that.
    All those who believe psychokinesis raise my hand

  7. #7
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    I am sorry guys - I belong in 1/10 scale....

  8. #8
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    No biggie.... just want to make sure you get the right advice!
    Whatever it is I just said... I could be wrong.

  9. #9
    Traxxas Marshal cooleocool's Avatar
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    Quote Originally Posted by kensul12 View Post
    I am sorry guys - I belong in 1/10 scale....
    I moved the thread for you.
    "Happiness depends upon ourselves." -Aristotle

  10. #10
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    As some membres mentioned , get a temp gun. It is best to keep it below 140F and gear low, best performance would be 90/19 or 86/16.
    Live life to the fullest

  11. #11
    RC Turnbuckle Jr. DiggerPede's Avatar
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    A few things to take note if you buy a replacement 12T Titan motor.

    First of all you need to break the motor in. There are a few ways of doing it. You can prop the rear wheels off the ground and let it run and 50% throttle for 20 mins. Or you could run it on a flat surface doing the same, just take it easy and dont go WOT. Then blow out the motor with air, spray electric motor/contact cleaner in the motor to clean it, blow it back out with air again, and lastly put 3n1 oil on the end bushings. I would do this every 4-5 runs depending on running conditions. This is what is considered your maintennce for the the motor. This will totally prolong the life of it.

    I would also suggest swapping the pinion for a 16t if it isnt currently installed. This will slow the truck down a little, but will give it more torque. Also suggest an IR Temp Gun like the guns above said (highly). Keep the motor < 150 or less to keep it from burning up. Be cautious on the terrain you are running, anything more than well manicured grass, which can cause the motor to heat up faster. Plus the outdoor temps make all the difference to. Another thing is if you run packs back to back, check the motor and see what its temping at. You may need to let it cool down for a few minutes.

    Last but not least if you havent already you might want to upgrade your wheel bushings to bearings. You will need (8) - 5x11x4, which is 2 per carrier. This will also help the truck to run smoother.

    Hope this helps ya.
    Weak Revenge
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