Cc: "Mike Sylvester" <shagste...@hotmail.com> Subject: KR> Flew yesterday. I've been working on an internal trim system and I think I finished it yesterday. The weather warmed up enough for me to test fly it and I was happy with the results. My original thinking was that I didn't want the drag of two surfaces working against each other like the trim tab does. I was looking for every MPH I could get. If I could go back in time, I would just do the Ray Allen trim tab system and be done with it. To all you builders out there, Keep working and stay with what you know works, All the guys that went before us have done all the testing.
Mike Sylvester kr2s builder Birmingham,AL. --------------------------------------- When I cut the tail off my KR and built a larger tail, I decided to use a spring biasing trim system, also in an attempt to keep the tail as aerodynamically clean as possible. I flew with it like that several hundred hours from 2005 - 2013, but would consider it to be a miserable failure. As the plane speeds up, the elevator control pressures load up and pull on the springs. It would never reach an equilibrium, regardless of the speed, so the plane was constantly pitching up and down and wouldn't ever hold an altitude. I could have improved it, but I don't believe I could have ever cured it with that configuration. I finally removed the spring biasing system and put a trim tab on the elevator with a Ray Allen trim servo. Details of both installations are on <http://jeffsplanes.com> On the SuperCub Clone I had a single bowden cable control to the trim tab as per Wag Aero plans. That cable started flexing and failed in flight creating a high speed and violent flutter that shearedmost of the rivets attaching the trim tab and caused some cracks in the elevator that had to be repaired. (Also scared the crap out of me!) The Cub was also modified so it now has a Ray Allen trim servo. -Jeff Scott Cherokee Village, AR _______________________________________________ Search the KRnet Archives at https://firstname.lastname@example.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org