OK I'm getting back to an old project from maybe a year ago, a tailwarp control system for combat planes.  I'm reworking an old Rumbler with what I christened some time back the "Stone Stabilator", no hinges or pivots, solid mounted 1/32" ply. tail that warps as shown. 

This will be the third model, two different designs, with this control system.  Note the tail assumes an airfoil shape lifting in the right direction.  On the earlier models it made for v-e-e-r-y smooth turns, and quick transitions from inside to out without the least bobble. 

I ain't an aerodynamics whiz, just a seat-of-the-pants kind of guy, this just seemed like something that might offer some advantage.  I'll post a flight report when I get it in the air if anyone's interested.

--Ray

P.S. the last 2 pics are of the earlier models.

Finally got out today and flew the flextail...never showed how I finished it, so it's pictured below.

I'd been flying my .061-powered LittleAxe and Frankenstone Arrow, so I had my 48' lines out...too lazy to reel 'em in and run out 42', I first flew the combat wing on the 48s.  Man! You wouldn't think 6' would make such a difference. It has a VA .049 on bladder pressure; got up with a less-than-perfect engine run, not bad, just not quite peak, and it really struggled to pull the long lines.  Didn't do much that flight but get it down in one piece.

Then I ran out the 42' lines and tried again.  Better engine setting too; made a world of difference.  The plane flies pretty near as I expected: Basic design is stable and sensitive--no difference there; this turned a little tighter inside and b-i-i-g outside-- needed much more outside control.

For comparison, I next flew an old stock Rumbler with the same setup--VA .049 on pressure (second picture below).This really is a sweet flying plane; maybe not a fair comparison since the older one is in perfect flying and fighting trim whereas the new flextail isn't;  but I had to admit I  haven't managed to improve on it yet.

Flextail needed more down--pushrod is straight, no adjustment there, so I loosened the horn and put a washer under the back of it, tilting it forward to gain more down/less up, and flew it again.  Better, closer to what I'm looking for; but it does require some line tension for real positive control. If you catch the wind wrong and momentarily lose a little tension--not slack, just light--it really opens up the maneuvers.

 The stab seems a little bit stiffer than my earlier ones.  I'm going to strip the finish and sand it down thinner to increase the flexibility, and try it again.  So far so good.

--Ray