Help! pressure deployed wing slats questions

[L Edge]

I thought that if I were to investigate the problem described by badpilot27, I would start with slats that were opened mechanically at my discretion. If they proved effective, I would then move on to automatic slats. Otherwise, we have several immediate problems: will they open, will they open simultaneously, will they be effective, and was it worth it? We can reverse this sequence and immediately know if it's worth it, and then proceed further.

Simple way is to hook a servo underneath the wing connected to the slot(each side) and set the extreme limits of travel so it is closed and then your maxed opening you want. If you know how to mix in your transmitter radio, using a pot or slider, you can go fly, try a setting, move the gap by the pot and try again.

I used the leading edge concept of the F-22 and automated them with a gyro with the net result of tighter turns(use of elevator) and slower landings. I found my max angle of deflection by regluing the flap every 5 degrees from 0 degrees to a max of 35 degrees. Settled on a max of 30 degrees RC model of F-22.
Gyro limits were set so when level, the flap was level(upward movement was dialed out and as the nose went up the flap went down. Higher AOA of F-22 always put flap to level position . If nose is pushed down, the flap always stayed level since no upper movement.

Look at wingtip to watch leading edge go down as he turns or climbs.

 

[Piotrsko]

If you get to working servo powered flaps and they deploy and retract sanely, leave that mechanism alone but experiment with size and extension distance

As Red Greene would say: "We're pulling for you"

 

[Tench745]

Might be worth building a test piece and sticking it out a car window to test the ease of extension/retraction without risking a whole plane. But then, it's foamboard, so maybe more fun to just send it.

 

[Air-headed Aviator]

Andy Lennon of "Basics of RC Model Aircraft Design" has seen success using fixed slats on a 60 inch span design called the Crow. While scale effect is important to consider with RC aircraft, the fundamentals of air pressure and flow stays the same. RC aircraft aren't so small that they adversely change how atomic particles move. As far as your concerns on the way the automatic slats work, in the end the key to their success will be making that mechanism as smooth operating as possible. The theory on how they work is that as the angle of attack increases the static point of the air will move from the immediate leading edge to below it. That should create enough pressure to encourage it to open as long as its smooth enough to roll.