HiI have a hirobo shuttle plus. Gyro Futaba 401. Servo rudder, align DS620 with voltage reducer to 5.1v.My problem is the servo rudder vibrates when the engine turn on. If the engine is not turn on, then there is no vibration.I have the same issue previously with my trex600. However it was resolved by just moving the gyro position. Same gyro and same servo rudder.When I say it's vibrating, the servo just keep moving from left to right and vice versa (very small movement, about 2mm). No problem during flight as the head lock still lock, however after 5 minute flight, the servo rudder become extremely hot.Any one has the same experience before that they can share?ThanksEric

It sounds like your gyro gain is too high and you're overworking the servo. Turn down the gain until the servo stops it's movement. That should fix your problem.

@ mydartsinger

Thanks for the input.

Have tried to reduce the gain and it works like a charm. The servo does not vibrate anymore. Not noticeable

However,I guess my real issue is still there, which is the servo being hot.

I guess vibrating is one cause.

I was also suggested by friends that there could be a binding issue. They mention that the tail blade is extremely difficult to be slide if compare to a trex.

It is kind of true. It is rather difficult to slide the tail blade compared to a trex.

Could this be because of binding?

Thanks

Eric

That's another very likely issue. The Shuttle's tail shouldn't be tough to move unless there's a problem. There are several causes of binding for the tail rotor.

1. Kinked tail rotor control rod guide tube. To ensure that this is/is not the issue, remove the ball links on the tail servo and on the tail control linkage, and slide it back and forth a bit. If it's tight, look the tube over for kinks and the rod over for bends. Replace accordingly (do not attempt to repair the bent/kinked part, as it can cause further problems). Check this first, as it's the easiest fix.

2. Overtightened screws. While you have the control rod loose, move the tail rotor linkage by hand. If it drags or takes more than a touch on the linkage to move, something is too tight. You want your screws tight, but not so tight that it locks everything down. Try loosening the screws by about an hour clock position at most at one time and repeat until you get a free moving tail. If you find after loosening the screws that any of them now have slop, tighten it just enough to get rid of the slop, but not enough to let it bind.

Once you have a free moving tail, ensure your radio trims and subtrims are set to 0 (neutral) and spool up the heli. If the tail continually turns one direction without input, remove one end of the tail rotor control rod and adjust the ball link to shorten or lengthen the rod to trim it as needed to get it as locked in as posible without radio trim/subtrim. Next, recheck your gain settings. Spool it up and see if it holds without wag or drift (there is a difference). If it wags, as it did before, reduce the gain. If it drifts (goes one way, you correct it, it goes the way you correct it, but it doesn't stop), you're gain setting is low and should be increased. Experiment to find a happy median.

If you still have a warm/hot tail servo once you get a free moving tail without gyro "wag" (the vibration you were describing in your first post), try reducing your gain even more (if you start seeing a drift, you've reduced it too much, and you should increase the gain a few points). If after getting all of that set right, you still have a warm/hot tail servo, you may need to replace the tail servo.