Fluttering Digital Servo's

[Rich B]

For what its worth...

First and foremost, this not intended to bash or insult any digital servo or Savox servo's in general. In fact, I am really impressed with the accuracy, speed, and performance from the digital servo's.

I just wanted to share this concerning some Savox SH-0255MG digital servo's that I have.

The servo's fluttered, jittered, and twitched after powering them up, this was very concerning for me.

I fiddled about with the servo's trying all different approaches to stop this. What I ended up doing was moving the arm back a tooth. I then took 12" extensions, one for each servo and installed a ferrite ring inline to take away any RFI (Radio Frequency Interference) out of the equation if this was present. After this, I re-centered each servo, and the fluttering, jittering, twitching ceased. What is now present is the aileron servo's making a creaking sound here and there on a re-centering adjustment... gotta love gravity, lol. I also corresponded with a Savox technician. I advised them of what I had experienced and verified that the creaking sounds present now from the aileron servo's is the correct function for the digital servo and it seems the heavier the surface they support to their size, the more they creak.

I do not claim this is a fit all for digital servo's experiencing what I observed, but that this is what worked for these servo's in this instance. If this assists anyone, I am glad to have helped.

Rich

Here is a picture showing several of the 12†extensions with the ferrite rings installed.

 

[3dNater]

I have had some success using ferrite rings on fluttering servos as well. For the most part though... it doesn't bother me that much unless they are doing it under a load. As soon as there is some pressure against them they usually quiet down. Some guys put the soft side of Velcro between the control surface and a part it moves past i.e stab, wing, etc. To provide just a small amount of resistance at center. It usually quiet most of the jitters down.

 

[3Daddict]

Vary good info. As you know, I was always told there was no way to get the servo to stop fluttering, and this was just "normal digital servo function". I always just left it at that, thinking there was nothing else I could do. And since they never jittered in the air I never thought much more about it. I would have never guesses all I had to do was put a ferrite ring on it to stop this. I think this is really good info, and just shows you learn something new every day LOL. Hope you enjoy the plane, so far it looks like you are doing a better wiring job than i did LOL.

 

[3Daddict]

I have had some success using ferrite rings on fluttering servos as well. For the most part though... it doesn't bother me that much unless they are doing it under a load. As soon as there is some pressure against them they usually quiet down. Some guys put the soft side of Velcro between the control surface and a part it moves past i.e stab, wing, etc. To provide just a small amount of resistance at center. It usually quiet most of the jitters down.

I have been the same way, they never flutter in the air so I just ignored them chattering and moving a bit on the ground. But I know a few older people I fly with who have never used digitals before think there brand new servos were broke LOL.