Can sombody please explain how to design a elevator and a horizontal stab? Like is there a ratio of stab to elevator? Im just asking because i have designed a new jet and im worried that my elevator isn't long enough to actually make the aircraft pitch up and down. But my Mig 15 has a pretty small elevator and it isn"t even in the jet exhaust stream and it still work well! Whats the secret?

oh and for anyone who wants to know, the median chord (center) of my horizontal stab is 3 inches (rounded) and my elevator in the center is 1 inch (rounded) and the planes weighs about 1.6 pounds.

Can someone help?

The ratio of fixed to movable varies from 1:1 to as little as 5:1 depending on the sort of model. All of these work fine but the smaller ratio elevators require more deflection angle to achieve a desireable level of control. The smaller ratios are typically found on trainers and gliders.

More important than the amount of movable area is the surface area of the horizontal surface being large enough to properly stabilize the wing and putting the balance point at a position that is in harmony with the size of the horizontal stabilizer and the distance from the wing. You can test this for yourself using the online CG calculator links found in the resource thread at the top of this forum's thread listings.