1/4 SERVO glitch PROB

[rcguy76]

I have a 1/4 scale servo hooked up to run my 7.5 OB and am having problems with glitching in the throttle servo. If I turn the servo right and left , occasionally the throttle servo gets a little spike just for a split second. I'm not sure if the little spike is enough to effect the engine, but I dont want to find out it does and have it smack the shore at full speed. I have tried different throttle servos and they all act the same way. Reciever battery is fully charged. I have tried it with and without fail safe. I dont really want to have add another battery to just power the 1/4 scale. I'm going to try a different receiver this weekend and see if that helps. maybe switch cystals?

Any other Ideas?

Thanks guys

 

[Propjockey]

So you have a 1/4 scale servo for steering and standard for throttle.....and when the steering servo moves, the throttle servo glitches.

What's the mAh rating on the receiver pack? What radio system are you using?

Try swapping the 1/4 scale for a standard servo...not for running, but just to see if the problem goes away.

 

[vanduzer]

how close is the radio to the boat when you are doing this. I f you are right on top of the boat with the radio sometimes you can get this to happen. Walk away from the boat and have some one watch the servos for you. AM radios have more of a problem of this then Fm

 

[wswatzell]

What are you using for your push rods? If you have metal rubbing on metal occasionally when the engine turns, this could cause the servos to glitch.

Or dumb question. How close are your transmitter & receiver & do you have the antenna are up or down on the transmitter? You could be getting a little feedback. I’ve had a problem with the servos going nuts if I had my transmitter antenna up & it was in close proximity (about a foot or so) from the receiver antenna.

I bet it is a metal on metal rubbing problem more than anything else if it only happens occasionally. Check the engine mount, the throttle cable against the side of the engine. Also check to make sure you don’t have any splits in the servo leads. If the insulation on one of them has been cut, or nicked, & the leads are really close together, that might cause it as well.

Good luck.

Let us know what you find.

 

[wswatzell]

If you don't have someone to ask to help out to watch the servos like vanduzer suggested, unscrew the transmitter antenna. that really shortens the range, & you can stand right on top of your receiver without a problem... just make sure you put it back before you toss the boat in the water!!!

 

[rcguy76]

Thanks for all the responses....

-I'm using a JR 3ch FM

-1100 mah Rec. Battery

-I will try switching to a regualr servo and see if that is the problem.....

-the pushrods are metal, but both ends have plastic locking ends, only place it might be rubbing metal to metal is where I have the front to back pushrods overlap and are collared together.

-it does it either way if the antenna is up or down, but I will try taking it off and checking

Once again, thanks guys for all the help, I dont want to crash this boat the first time out especially since its been sitting ready to get wet since june, Unfortanately the OB I orderd in march didn't arive till last week

 

[GTR]

Hi there

There is something else you can try - use a Y harness to hook up your 1/4 scale servo and provide bateery power through the same channel lead. What sometimes happens is under high load the 1/4 scale servo draws so much current (more than the receiver was designed for) it can cause power feedback. This is really common in 1/5 scale cars and this set-up eliminates the problem 99% of the time. Will only cost you a few bucks and may solve your problem.

GT 8)

 

[[email protected]]

Are you by chance running a tuned pipe?? Maybe the pipe is hitting or touching the header. I learned recently that will cause glitching. Also, how are your servos mounted down?? Do you have them bolted down with metal screws?? If so go to aluminum.

Last other than what the other guys have told you, you can try switching your crystals. They also go bad and can cause bad stuff to happen.