Electric trim

[dirkverdonck]

Hi Glenn,
Thanks for the pic, I will be able to figure out the dimensions from the pic and will of course take into account the smaller size of the OneX and the more forward location of the hinge line.
Dirk
OneX 117

[Concorde]

Hi Steve,
Thanks for the info. Friend of mine has his servo inside the tail fairing and is very happy with it except that he isn't getting full travel on it. Since you're saying that the full travel is 1.5" and RA has 1.2" of travel and we're talking about only .3", how about making the tab just a bit longer to make-up the difference. I'm not an aeronautical engineer so wouldn't know if this has any negative effects.
Like to hear from others.
Ben

[Rynoth]

Just chiming in on possible "negative effects" of potentially large trim tabs, myself also being no aeronautical engineer. That would be for control surface flutter. A manipulated trim tab adds weight to the trailing edge of the control surface, moving the center of gravity of the control surface aft. Flutter (in my understanding) can appear at higher airspeeds due to the center of gravity of the control surface being beyond the center of lift of the control surface (increasing the possibility for oscillations), therefore adding weight via a trim tab would move in the direction towards increasing the potential for flutter. The kits I imagine, by design, have a Vne speed that is appropriate to avoid flutter when built per the plans. Whether this is actually a concern in Sonex elevators I couldn't say, just mentioning it as food for thought/discussion.

http://aviation.cours-de-math.eu/ATPL-0 ... lutter.php

[Concorde]

Just chiming in on possible "negative effects" of potentially large trim tabs, myself also being no aeronautical engineer. That would be for control surface flutter. A manipulated trim tab adds weight to the trailing edge of the control surface, moving the center of gravity of the control surface aft. Flutter (in my understanding) can appear at higher airspeeds due to the center of gravity of the control surface being beyond the center of lift of the control surface (increasing the possibility for oscillations), therefore adding weight via a trim tab would move in the direction towards increasing the potential for flutter. The kits I imagine, by design, have a Vne speed that is appropriate to avoid flutter when built per the plans. Whether this is actually a concern in Sonex elevators I couldn't say, just mentioning it as food for thought/discussion.

http://aviation.cours-de-math.eu/ATPL-0 ... lutter.php

Thank you for sharing Ryan very informative. Would be interesting to know the effect of adding an inch or 2 to the trim tab .

[vwglenn]

I've had my Sonex up to 180mph for a low pass at a friends grass strip. No signs of any control anomalies.