...continuing from Strange airfoil:

However, I do enjoy intentional experiments very much, and I came up with what I hope will be a good one, better than the shelf idea.  I'll open a new topic for it. 

Speaking of intentional experiments, flight trimming a plane seems to me like a series of small experiments.  Earlier this year I trimmed an Imitation, and found the experience both educational and highly rewarding.  It's the most advanced design I have attempted to trim.  Previously I had tended, like a lot of people, to stop trimming when it got "good enough".  One former member of our club used to shout "don't change a thing" at every opportunity.  By not following that instruction I ended up with a better-performing plane, and a deeper, gut-level grasp of the interplay among the various trim adjustments.  It's one thing to know the principles and another to experience them in action.  Much fun was had.  And of course I have much more to learn.

The new experiment involves fixed flaps.  Our club has caught Skyray fever recently, and they are sprouting like rabbits.  I was flying the club Skyray last Saturday (an orthodox kit Skyray: .20FP BBTU, no adjustable leadouts, crashed and repaired).  I noticed that the plane stalls in the last corner of triangles, and the stall can be reduced somewhat by softening the corners (no surprise there).  It occurred to me that this plane might be a good opportunity to try adding fixed flaps temporarily with tape and pins to see if the stalling improves or if fixed flaps are mostly decorative.  I'm curious if anyone has tried this experiment before: the same plane with and without fixed flaps.   

If you want something even more interesting, try fixed, deflected flaps.

Is this a serious suggestion?  It's sometimes hard to tell with Howard The Cryptic.  If yes, would this be a pair of flaps, one deflected up, the other down?

There are too many interacting factors at work.

Just shoving fixed flaps onto a Skyray is going to tell you more about increasing the wing area, or decreasing the tail moment arm, than it is going to tell you about fixed flaps by themselves.

The Cow would have made an interesting Slow Combat plane.  You tool around at 4 mph a foot off the ground, then wait for the other guy to come up behind you and snap a nifty 3 foot loop as he whizzes past, hopefully without cutting your own streamer.

Would you mind describing in more detail, or posting a sketch of the strange movable flaps on the blue Streak, if it's not too much trouble?  Thanks.

The new experiment involves fixed flaps.  Our club has caught Skyray fever recently, and they are sprouting like rabbits.  I was flying the club Skyray last Saturday (an orthodox kit Skyray: .20FP BBTU, no adjustable leadouts, crashed and repaired).  I noticed that the plane stalls in the last corner of triangles, and the stall can be reduced somewhat by softening the corners (no surprise there).  It occurred to me that this plane might be a good opportunity to try adding fixed flaps temporarily with tape and pins to see if the stalling improves or if fixed flaps are mostly decorative.  I'm curious if anyone has tried this experiment before: the same plane with and without fixed flaps.   

  Hard to tell unless you also ballast it up to the same wing loading. Just adding fixed flaps will increase the wing area much more than it adds to the weight so it should help considerably.

    Brett

How long is a side of a Flight Streak-sized equilateral flap?

About 2.5", as I recall.