Throttle Jitters

[crvogt]

A friend brought over his new Gas Tunnel Hull, a really nice boat about 5' long with a weed wacker type motor. He was having trouble with a RAM 62 failsafe, with failsafe installed the throttle has a serious jitter problem. adjusting the delay did not solve the problem, adjusting the set point seemed to help but there was still some jittering, with a boat that big and powerful, I would not run it with any glitching in the throttle servo. With out the failsafe the servos are rock steady, the radio TX and reciever are Futaba and a Y connector is installed to help power the larger rudder servo...
Any ideas on the source of the "noise" on the throttle servo with the failsave installed????

Thanks
Carl

[Tachikaze]

Carl,
If as you say you remove the radio from the boat and it is rock steady with the throttle servo attached, is it rock steady with the throttle servo and steering servo attached?
Can you stand off from the radio about 30-50ft with the transmitter antenna down? If not you may have a reception/transmittion problem.
You mentioned you have a Y connector running to the large steering servo, what is the other end of that Y connector attached to?
Things to look for:
1) What is the voltage and amperage of you receiver battery source? If you do not have the voltage to run that larger steering servo you will loose power to your receiver and get the jitters. It is nice to have near 6V with an amp of power.
2) You mentioned that if you adjusted the trim position of the failsafe there was a decrease on the jitters. Check to see if your neutral throttle or steering postion of the servo at its attachment is under tension. If the servo is under tension it will be drawing power and will attempt to pull against that tension. There is be no ( or very little) servo noise when that servo is at neutral.
3) Also check the throttle servo, as you engage the throttle that servo should produce very little servo noise also. If it is produce a lot of noise ( like it is while under tension) then you need to adjust its position so that it can move from a neutral position to a drive position with as little resistance as possible from the throttle of your engine.
4) Check the receiver position in relationship to the other objects in the boat. You do not want that receiver next to a servo that is under strain ( feedback from the servo jitters). You also do not want that to be near that failsafe. The fail safe will produce some RF interfrence and produce a feed back into the receiver thus complicating the RF.
5) The receiver and the receiver antenna do not like metal or graphite structures. These will interfere with signal reception. Make sure that they are not resting on any such objects.
Good Luck
Tachikaze:cool: