It may be that you need better servos. $4 servos.

Operating Voltage: 4.8-6.0V
Stall Torque: 0.6 kg.com (8.4 oz/in) at 4.8V
Operating Speed: 4.8V: 0.09 sec/ 60?
Weight: 8.0g (0.28 oz)
Size 22.5 x 12.8 x 23.7 mm

Very low stall torque, your full flying stab (elevators) will need a higher torque servo. I would recommend somewhere around 1kg minimum.

These have worked well for me in this price range. I use them for small foamies.

http://www.unitedhobbies.com/UNITEDH...ec_Micro_Servo