JR9000S Jitters

[pink_sleeve]

The servo jitters like it is trying to center so i opened it up to see if the gears are bad but they all look fine so i'm confused. When it's together though and the servo horn is on when you turn it there is a touch of free play so something has to be messed up. The only thing i see that looks odd is the top of the case where the gears are is that the center gear that has the bushing that seats in the case at the top looks to be oblonged to me? Could it need a new case or am i overlooking something. They have 3 year warranties but i lost my receipt and the hobbyshop i bought it from went out of business last may or june so what can i do?

[mr. losi]

i have a ko servo that does the same thing...

[pc9840]

Just send it in for service. There were some motor issues that I know of with the 9000 series servos. Although this doesn't sound like a motor issue they will probably just send you a new one.

[nitro neil]

i had the same problem and the top of your case is most likley bad. I wouldn't think that is causing the jitters. I would send it in they have excellent service.

[infanterene]

I have a 9100s that is 3 weeks old. It has some play but no jitters. I would send it in. JR has the best warranty.

[dethklok151]

yes.it is probably the top of the case.it is a common pproblem if they last long enough.with a digital servo,any slop will give it the jitters,as it cant ever really find center.try writing while you hold a pen so the pen is as long as it can be,then hold it close to the point.same theory.when the tires are on the ground,your jitters might go away,as the friction of the tires on the ground will hold pressure on the servo,one direction or the other,which will help allow it to calm down.the slop in the gear train and case will let the little gears "bounce"from one direction to the other without moving the horn,so the servo is constantly going back and forth.digital servos are that accurate.it is called "deadband".digital servos allow you to adjust deadband,which requires a programmer,around 120 bucks i think.reprogramming the servo deadband could also help,but i have not tried it.giving it a wider deadband would make the servo center less accurately,so as you turn left then let go of the wheel,the car would most likely still pull to the left,then if you turned right,and let go ,it would still pull to the right.
replacing the servo case will most likely fix it.

[pink_sleeve]

Thanks guys i put a new upper half case on it and the jitters are gone. I figued it was the case since the whole being dameged was allowing slop in the gears