Originally Posted by target
Are you going to use the aluminum frames with the bearing to mount the flap servo, Tuan?
I sprung for a set with my 4.0, and glad I did. Between that and the full sized 6125, I have not yet had to touch my flap setup since I built the plane, and its still quite tight.
Those would probably be a bit of overkill for the X's. The linkages are not so short like those on an F3B plane where the pushrod compression forces are huge and thus transferred to the servo arm, bearings, case, mounting frame, then skin.
I am doing the flap servos with the wood frame, but block them so they tie into the upper skin and the main spar. I would think this method yield less flex than using the aluminum mount without tying into the spar or upper skin.
The bearings would be beneficial as they do provide extra support, however the amount of time the J planes are in high speed mode is but a few seconds here and there and one never pulls enough flaps in the high speed case that would make the extra support of the external bearings a necessity if the rest are solidly installed.
Bottom line, for me at least, is that I would worry more about the arm slipping on the output shaft than the flex of that final gear if there was that amount of compression force on the servo.
I'd actually like to use some flat carbon pushrods with holes at the ends that a rod slides into. the rod is held in place by carbon tubes at the flap end and an aluminum servo arm. The thicker wing allows this system to work very nicely.
Like that in the picture courtesy of fly-up85