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  1. #1
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    Ran at the beach, now motor doesn’t last

    Hey all. New here, so sorry if this is covered elsewhere. My son has a stock Rustler that we ran at the beach last July. We dusted it off and rinsed it lightly, but didn’t do a real thorough cleaning at the time. It did ok for a while since then, but by Fall, the battery gave up due RJ corrosion, I think. Got him a battery and charger for Christmas and the car worked, but runtime was really short. I assume we hunker you the motor with sand and salt. Am I right? Thinking of buying a stock motor replacement and seeing if full life is restored. Thanks in advance for any advice.

  2. #2
    RC Qualifier nebulous.cow's Avatar
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    New Nimh style batteries (the type of battery that came with your son's rustler, and, presumably the type you just bought) need to be used a couple times to "wake up". For example, I just got a new Traxxas Mini summit, which comes with a normal Nimh type battery, like every traxxas vehicle comes with. The first time I charged it and drove the truck, it was extremely slow, and literally lasted 1 minute.

    I put the battery on my special high-end battery charger, and pushed a few charges and discharges through it, and the data showed that over 3-5 cycles, the battery regained its full capacity, as well as lower resistance, which is all good and normal.

    I do this same procedure with new RX batteries I get for my nitro powered models to ensure they are 'woken up', and ready to go.

    So before you replace any motors, I would at least use the battery a few more times. You don't need the fancy equipment I have, just charge and drive the battery normally a few more times and it should work better. If it doesn't do well after 3-5 more times driving it, or the rustler obviously has some rolling resistance, or the motor gets hot quickly, investigate the car, it may have seized bearings preventing parts from spinning.

    Salt water is pretty bad for all things RC, when I used to drive my rustler on the beach, the first thing I did when I got home was hose the car off pretty good with my hose or shower, to at least get the salt out, then it's just water, and you can maintain the car for water alone much easier. WD40 is good for the wheel bushings, contact motor cleaner is good for the motor, and compressed air is good at drying the car. Just don't use the air too much/hard, as you can blow water into places it shouldn't be.

    Hope this helps. Odds are, your fix is simple, even worst case.

    -Mike

  3. #3
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    thanks - great info. We have only run it 3 times since getting the new battery. I’ve currently got the new battery on a Prophet Sport Mini charger at 2 Amps. Any concern about charging at different amperages?

  4. #4
    RC Qualifier nebulous.cow's Avatar
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    For Nimh batteries, if you charge too quickly, the battery will not receive a full charge. I would stick to around 1C charge rates for Nimh batteries. Which means, if the battery says "3000mah" on it, a 1C charge would be 3A. I would not go much over 1C, as the charger will say the battery is done charging, but it won't be as charged up as it can be. So charge slow. If you want to charge fast, get Lipos, they can handle it.

    Under 1C is fine as well. I think 2 Amps should be fine for a stock rustler battery. Just don't charge too fast and you'll be golden. I think Nimh batteries don't suffer it as bad as old NiCd batteries, but IMO, it's a good idea to every now and then, make sure you fully discharge the battery in the truck, and then fully charge it, just to make sure it won't develop any "memory effects". Look up nickel battery memory effect if you want to know more about what I am talking about.

    Hope this helps, hope you get to have fun with it soon!
    -Mike

  5. #5
    RC Qualifier GotNoRice's Avatar
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    I agree you should check your bearings. They can and do seize with corrosion from salt water, and the sand only makes it worse. Upgraded bearing will help a lot, as they have better seals which will keep the water out in the first place. You can get an entire kit of replacement bearings from places like Avid for about $20.

    If you are running brushed, you're best bet is to probably buy a new motor. Brushless will hold up better to those environments, but still have bearings in the motor that will die eventually from things like salt water and sand.

  6. #6
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    all great stuff. Thanks to all of you. Got the battery to wake up and the kids got to have some fun yesterday. Got 25-40 minutes in run time out of it over 3 or 4 sessions.

    Now, on to the next dilemma. While cleaning it up, tightening some things and generally putting things back in place after yesterday’s fun, I decided to swap the gears out with the optional set that came with the rustler. I was interested in the higher top speed that would come from the 28/86 combo as indicated in the manual. Well, it performed well for a few minutes, but then the motor began smoking and wouldn’t respond after about 10 minutes.

    I think it MAY be some combo of the battery running low (didn’t charge it at the end of the night) and the engine being less than clean. But, I won’t be surprised if my gearing experiment finally pushed something too hard in there. I think I’ll order a motor, a bumper, and that bearing kit this week.

    What’s a slight step up motor upgrade I could do, if not just a stock replacement?
    Last edited by Tyjdavis; 05-04-2020 at 12:43 AM.

  7. #7
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    The optional gear set (28/86) is designed for high speed runs on pavement only. Off-roading with that gear ratio will overheat the motor.

    I’d just replace it with another Titan 12t. The Titan is a good motor if you keep original gearing, clean it occasionally and lube the bushings. It’s plenty powerful and inexpensive. Lots of people will go crazy with brushless set ups (which I’ve done too) but on my second Traxxas (Stampede) I’ve stuck with the Titan and been happy - 2 years now with the original motor.
    Last edited by massenrg4; 05-05-2020 at 11:48 AM.

  8. #8
    RC Qualifier GotNoRice's Avatar
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    Quote Originally Posted by Tyjdavis View Post
    I was interested in the higher top speed that would come from the 28/86 combo as indicated in the manual. Well, it performed well for a few minutes, but then the motor began smoking and wouldn’t respond after about 10 minutes.
    Heat will kill just about any motor. Were you keeping an eye on temperatures (before it began smoking)?

    Also, one thing about brushed motors is that they literally have holes all over the motor for ventilation, etc. All of those holes allow dust, dirt, debris, water, salt-water, etc right into the motor. This is exacerbated by the fact that the 2wd Rustler runs the motor in the rear where it is very exposed, as opposed to most Traxxas 4wd vehicles where the motor is up inside the chassis and relatively protected.

    Back when brushed motors were more popular, it wasn't uncommon to dunk your motor in a glass of distilled water and actually run it under-water for a short period in order to clean it after running in a harsh environment.

    Brushless motors on the other-hand are mostly water-tight. The only area of the motor that ends up directly exposed to outside contaminants are the bearings, which can potentially be replaced.

    So I would give serious consideration to a brushless upgrade. You'll end up spending the same money anyway replacing the Titan 12t every other run.

  9. #9
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    Thanks again. We definitely weren’t monitoring temps. I knew the higher top speed claim meant we should run it on the asphalt only, so we tried, but inevitably, we ended up in the yard some. Must have overcooked it. I’m going for a fresh titan this month. Might go for brushless once he and I both have a little more experience.

    Can brushless be throttled to only allow for speeds like we’re getting right now out of the Titan? My kids are all 10 and younger. If I put something too quick in their hands they’ll just destroy it. The titan is about all we can handle right now.

  10. #10
    RC Qualifier GotNoRice's Avatar
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    Quote Originally Posted by Tyjdavis View Post
    Can brushless be throttled to only allow for speeds like we’re getting right now out of the Titan? My kids are all 10 and younger. If I put something too quick in their hands they’ll just destroy it. The titan is about all we can handle right now.
    -The Velineon system has training mode, which will limit you to 50% throttle.
    -You could put in a smaller pinion, potentially even smaller than the stock pinion.
    -Buy a lower KV motor. Stock Traxxas Velineon system is 3500kv, but you could get a motor in the ~2400-3300KV range for slower speeds with the same battery and gearing. Avoid high KV motors.
    -Keep it to 2S lipo, avoid 3S LiPo (until you want more speed). 2S LiPo with stock gearing is not really that fast.

  11. #11
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    For a speed comparison I took my son's stock Rustler VXL with a 2S Lipo (in Training Mode) and drag raced it against my daughters brushed rustler with a NiMH battery in Regular Mode and the brushed was just a little faster. I did replace all the bushing in the wheel hubs with bearings on hers, so I know that helped it a little.
    Also don't just junk the old motor and electronics. Check with Traxxas first. I read something about being able to trade in your old Traxxas motors and electronics and upgrading both for less than going out & just buying them new. So doing it this way might be a little but more $$ now but cheaper in the long run and you get a brushless system and better electronics.
    You can use the same battery for now & then later on get a Lipo to make it a little faster, then take it out of training mode for even more speed.

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