servo causing throttle jitters

[truckus]

hey everyone,
Been putting together a stock super clod in the background and finally got to test it tonight. I got a Futaba PL am tx, new Hitec HP-2rnb am rx and crystal, new Traxxas XL5 esc, fresh 5000mah turnigy lipo, and a new JR z650m hi torque metal gear servo. Throttle channel works fine and so does steering but sometimes at full lock while holding the truck, the throttle all of a sudden engages for a violent half-second in reverse. I can sometimes duplicate it on the ground while at full lock and stationary, or while driving and turning the wheels to the left and right quickly. I've put a ferrite ring on the steering servo channel's leads but still got the problem. Could it be that the hi torque servo's draining alot of juice from the RX momentarily, causing it to glitch? I've connected a normal servo temporarily on the outside to check the channel and it works well without inducing glitches. Do you think the receiver's not up to par? help!!!:-(

 

[Jerry Matoon]

Where is your receiver in relation to the battery, ESC, and wires running to your motors?

Jerry

Just looked at Tower Hobbies website. I don't know this for sure as I don't have one of these receivers to test; but the listing states that it isn't compatible with Futaba radios; only the Hitec.

Are there others that are running this Tx/rx combination; or are you using it in another one of your trucks?

 

[rx78gp02]

sounds like you may have freid wires touch metal.
at least thats from my experience.

but your building a stock clod in a plastic frame, so thats unlikely.
check your connections and wires to make sure that they are insulated from one another.

 

[cpe mt]

You need an external BEC. The servo is drawing more power than the RX can provide, and it will cause glitching exactly as you described.

External BEC

 

[truckus]

My LHS owner recommended it but I'll check again on the compatibility. I've never used them before but I have an extra one to use in a tlt-1. It actually drives well until I go full lock left/right or quickly go left/right. The external BEC sounds promising: I have some model airplane friends who needed to up the voltage for all their servos in their planes and they have those external BECs. My planes have only four servos or less so I never had that problem or looked into it. So I assume the external BEC plugs into the "Batt" part of the reciever and is spliced into the battery/esc leads somehow?
In the meantime I'm gonna swap in a RX from my other (normal servo) trucks and put the Hitec in a lower servo load application (tt-01 car). Hey thanks everyone I appreciate it!