Results 1 to 10 of 10
  1. #1
    RC Qualifier
    Join Date
    Dec 2006
    Location
    Barrie, Ontario CANADA, EH!
    Posts
    290

    No servos work properly!

    Ok, Ive tried a JR Z4750 (94oz .12sec), Hitec 625mg (96oz .15), Hitec 645mb (133oz .20sec), JR Z650m (144oz .17sec) and an HPI SF-2 servo as my throttle servo and I am having the same problem with all of them. With the stock TQ3 TX/RX any (and I mean any) resistance put on these servos from the throttle linkage makes them hum like they are under heavy load. I have spent hours with the carb angle, TRS, collars, different servo arms, EVERYTHING! and I cant get a single servo to "be quiet" while under load.

    Now i know you may say that there is a problem with binding or over extending, but it still hums at quarter, half and full throttle with no TRS hooked up, no brake hooked up and carb opens smoothly. It seems the second that the servo arm (the pivot ball thingy?) touchs that collar on the throttle linkage the throttle starts to hum like it is under some heavy load, but it cant be. This happens to all 5 servos listed above (inclding the stock 2055). Even with just the servo being held in my had and putting my finger on the servo arm to give it resistance it does the same thing. Is this common?

    Could it be a bad TX or RX? could it be interference? It is fine stationary when not under load.

    I've pulled all of my hair out on this one and cannot figure it out.

    Any help would be appreciated.
    "I love the smell of Nitromethane in the morning"

  2. #2
    RC Qualifier
    Join Date
    Jan 2006
    Location
    st pete fl
    Posts
    790
    are you running 6 volt receiver pack?
    garage,Jato-revopicco26-savage axial28-

  3. #3
    RC Qualifier
    Join Date
    Dec 2006
    Location
    Barrie, Ontario CANADA, EH!
    Posts
    290
    yes, factory battery...fully charged
    "I love the smell of Nitromethane in the morning"

  4. #4
    RC Qualifier
    Join Date
    Dec 2005
    Posts
    344
    yes it is common to hear a hum wile the servo is under load it should stop at idle if the linkage is set up right.
    FAIR TAX:
    Worried about china, outsourcing, future of social security, imagration, and high taxes? Vote for the fair tax (HR25 and S25) its the only way this eagle is gonna stay aloft.

  5. #5
    RC Qualifier
    Join Date
    Dec 2005
    Posts
    344
    It should be quiet with no load. The hum is the servo resisting your thumb pressing on it and is normal. When you take your thumb off it it should quiet down. I have yet to see/hear an absolutely quiet servo when its being operated\placed under load.
    FAIR TAX:
    Worried about china, outsourcing, future of social security, imagration, and high taxes? Vote for the fair tax (HR25 and S25) its the only way this eagle is gonna stay aloft.

  6. #6
    RC Qualifier
    Join Date
    Dec 2006
    Location
    Barrie, Ontario CANADA, EH!
    Posts
    290
    I just worry because so many people are reporting burnt out throttle servos and it sounds like I might be on that same path if this sound isnt normal. Why doesnt my steering servo (JR Z650) make that noise while on my work bench turning the wheels back and forth? I dont get the same hum noise as the throttle.
    "I love the smell of Nitromethane in the morning"

  7. #7
    RC Qualifier
    Join Date
    Mar 2007
    Location
    minnesota
    Posts
    497
    you could use a bigger servo horn, is the spring to tight? you could strech it a little, very little, i burnt out 3 servos on mine trying to get the rb323 carb to work properly and finally got it to work with out ruining a servo

  8. #8
    RC Qualifier
    Join Date
    Dec 2006
    Location
    Barrie, Ontario CANADA, EH!
    Posts
    290
    Quote Originally Posted by entjoles
    you could use a bigger servo horn, is the spring to tight? you could strech it a little, very little, i burnt out 3 servos on mine trying to get the rb323 carb to work properly and finally got it to work with out ruining a servo
    Ive tried different (larger) servo horns and I have tried it with the TRS completely removed and still the same thing...still stumped
    "I love the smell of Nitromethane in the morning"

  9. #9
    RC Enthusiast
    Join Date
    Jul 2006
    Posts
    44

    servo hum

    It's the spring return for the carb stretch it a bit

  10. #10
    RC Qualifier
    Join Date
    Dec 2006
    Location
    Barrie, Ontario CANADA, EH!
    Posts
    290
    Quote Originally Posted by EASTCOTT
    It's the spring return for the carb stretch it a bit
    If it is the spring, shouldnt the hum go away if i completely remove it? It still does it when the spring is OFF the truck.
    "I love the smell of Nitromethane in the morning"

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •