One correction I thought about. The angle attack of the up and down spades are probably the same. But the angle of the spade arm creates a mechanical advantage for the up aileron spade whose lift and drag both try to lift that aileron farther up and have a longer moment in relation to the hinge line.
The other spade which is closer to the wing now on the down aileron has up lift but it's drag which may be more important is nearly in line with the hinge line so it has much less mechanical advamtage than the other spade. This would explain the use of low aspect ratio planforms which create a lot of drag per degree of angle of attack. I'm just trying to reverse engineer these things but so far it would be easy to quantify my theory.
Anyway, we know they work
But It can't be just that thier area is forward of the hinge line because they are way too small to have such a large effect.
Personally, I think for some reason they have been very mystified. I'm not really sure why. I know that there are a lot of mystics about things that are really simple but haven't been explained well or people just don't take the time to understand. Spades are a little different in that there may be only a few IAC-type aerobatic aircraft designers in the world right now and probably less of them have really taken the time to study aileron spades or write it down for the rest of us knuckeheads. So no wonder they are not mentioned in aerodynamic texts ect.
I've seen average joe's like me do some pretty amazing things so if someone out there want's to try spades - just go for it. Practical experience and experimentation can trump a genius in a chair. When it gets done right I bet it would be worth it. I'll sure the heck try it but I'm rather busy and slow to build so somebody will probably beat me. Salright -it's all good. I have some eagletree stuff on order....
If Jim Kimball finds them to be hard to set up - they probably are - at least on a full size airplane where "aileron catch" would be pretty risky and I'm sure would scare the crap out of anyone messing with thier spades. But I think the key would be to emulate the full size methods closely and start with small spades while checking the amps to that servo and making small changes. Wouldn't it be worth it to get rid of 3 to 7 servos, power managers, battery weight ect?