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Thread: Servo Jitter

  1. #1
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    Servo Jitter

    Help
    Just entered the world of nitro engines. Have purchased 2nd hand Jato 3.3 and both servos are jittering.
    It has the 2.4GHz Traxxas link radio gear.
    When pulling throttle servo kind of bounces back and forth and when turning steering it judders back and
    forth as it attempts to get to full lock. Also when turning steering side to side throttle servo sometimes
    flitters about a bit.
    I have taken servos out so there is no load on them but still does the same.
    Receiver has green light but flickers red when actuating either servo - Is this normal???
    I took lid off receiver and there is a metal bit on PCB which possibly looks scorched - Could this be issue??
    Not sure if receiver is knackered or something more sinister.
    Any ideas anyone

  2. #2
    Marshal Double G's Avatar
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    Could be that or the batteries are in need of replacing (or in the case of a battery pack, needs recharging).
    The Super Derecho

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    Wow
    Thanks for fast response.
    Should have said have got new batteries in transmitter and car.
    If i'm honest they are dodgy cheap ones but they are new, could that be all it is??
    Maybe I should treat myself to some Duracells in the morning!!!

  4. #4
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    Thanks double G.
    Just put in decent quality batteries and she's off.
    Would never have believed it.
    Still getting the odd random twitch when nothing is pressed but I can live with that!!
    Probably worth investing in battery packs for receiver and transmitter I guess.

  5. #5
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    Ran jato for first proper run today.
    Duracells lasted about 30min in reciever, is this normal??? cos I lost steering and throttle control and checked servos which were
    twitching like at first. Do people change batteries this often or do they fit battery packs???
    Finally got her tuned right (HOW FAST!!)and had about 2min of caning it before losing suspension pin, trashing rear alloy tie bar
    and ripping up brand new anoconda - gutted

  6. #6
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    Quote Originally Posted by Madsieadams View Post
    Ran jato for first proper run today.
    Duracells lasted about 30min in reciever, is this normal??? cos I lost steering and throttle control and checked servos which were
    twitching like at first. Do people change batteries this often or do they fit battery packs???
    Finally got her tuned right (HOW FAST!!)and had about 2min of caning it before losing suspension pin, trashing rear alloy tie bar
    and ripping up brand new anoconda - gutted
    30 minutes isn't much at all. My mate had a similar issue with his Tmaxx. It turns out one of the servo's was faulty, and making the other ones twitch, and the batteries die fast.

    As for slight twitching when nothing is pressed, that's pretty normal.

    I would suggest a battery pack, in the centre of the car.

  7. #7
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    Thanks Mindreader
    In the middle for better COG?
    Might have to stick with Duracells for now anyway as ordered the brake upgrade kit last night which the missus doesn't know about
    yet!!

  8. #8
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    In the middle so the front stays on the ground
    The packs are also better. Last longer, etc.

    Try disconnecting a servo, and turning it on, see how long the batteries last, then try swapping servo's.

    Might not be your case, but it was for the Tmaxx.

  9. #9
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    Get a transmitter pack and take off all the servo horns and recenter them. Make sure you adjust all of your transmitter controls back to zero and then see if the jitter is gone.
    --
    Nitro-J-Rod

  10. #10
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    Taken servo horns off and re-centered. No random jittering now - nice one jarod
    I've noticed that if the throttle servo is open and the steering servo is turned both servos jitter, especially the throttle servo.
    If the steering servo is fully turned opening and closing the throttle servo has no jitter effect.
    Whats that all about? Swapped servo leads on receiver and still has same issue.
    But noticed when using throttle to control steering it gives much more travel on servo so i'm thinking that receiver or steering
    servo cold be at fault.
    Doing my head in now
    Still waiting for suspension pins to arrive - trouble with living in UK no one stocks parts so have to wait for them to float across the pond!!

  11. #11
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    You may be going past the end point limits on those servos. You never really want to push them beyond the end points. I have mine adjusted to about 93% of maximum throw to minimize the effect. If you can adjust the servo end points on the stock controllers, I would try that first. Also, if you can record a short video and upload it to a site for us to see we might be able to resolve this a bit quicker for you. I know my servos buzz load when I they are under stress. That is pretty normal. I have also had jittery servos before and one was just bad. The circuity was just whacky.
    --
    Nitro-J-Rod

  12. #12
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    How do you adjust the servo end points?

  13. #13
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    dude if you have that problem i suggest that you take it some where to get it fixed. I had the same problem with my traxxas
    jato 3.3 and they had to replace it. You can try to fix it to save money.
    Thanks
    Traxxas-WRX

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