wynnbr

My Feedback: (2)

II recently purchase a Funtana from a guy that was outfitted with DS811 servos except the Rudder which has a DS8411.. I don't know much about JR servos as these are my first...

However, today attempted to fly the Funtana 90 powered by a YS 91.. As I was running the engine for the first time put about a tank through it, I noticed the tail feathers were jumping all over the place, I just figured the vibration from the engine was making the servos jump around trying to keep centered. I ran the engine dry, engine stopped, but the servos still jumping looking like they could not find center.. All of them jumping..
I then applied full up on the elevator and slowly return to neutral and the servos stopped jumping.. Then pulled back on the elvelator again, but this time letting go of the control allowing it to spring back to neutral.. This action started the servo jumping again and it would not stop until I either grabbed both the elevators for applied full up on the radio and slowly returning to neutral.

What gives here? After plugging and unplugging all the servos I determined that one for the servos was causing the issue.. I am a little nervous flying with these servos.. Can they be serviced/Checked out by JR???

What would you suggest?

Thanks
Bill Wynn

coony2787

My Feedback: (33)

I want too here the answer on this cause i'am having the same problem also on a u-can-do 40 size.


Chad

wynnbr

My Feedback: (2)

I guess no response from JR rep..........

dsnyder

That is likely caused by the play in the output gear of the 811 since it is a single ball bearing servo coupled with the high resolution of the servo and large throws. Without any load on the servo, it may jitter a bit as it tries to find center. This won't happen in the air as flight loads will prevent it from happening. Things to check to minimize this are to make sure that the servo mounting screws are not too tight, mounting rails too tight against the servo, slop, loose hinges, too flexible pushrods, restrictive hinges, etc. If it does not stop with light pressure on the surface likely the servo pot is worn and needs replaced.

I was out of the office last week, and yesterday afternoon, and am trying to catch up. In addition, I make no guarantees of any turn around time on answers.

KevinBourland

My Feedback: (9)

This is really funny.......

I am having the same exact problem on my Funtana 90 with the same servo's, DS811's. I do have a new one on the left elev. and it seems ok. I guess that I will order new gear sets for the rest.

Thanks for this post guys!!

This was a very disapointing weekend to not fly the F90.