I have a Maestro 6-Channel USB Servo Controller HiTec HS-422 servo motors
but they run only 90 degrees, how can I adjust them at 180 degrees?
sorry for my bad english.
90 degrees is a typical maximum range of a hobby servo’s motion. You can try slowly increasing the Min and Max values on the Channel Settings tab of the Maestro Control Center. Once you notice some kind of mechanical strain or limit, back off the values a little bit. Note that servos can sometimes destroy themselves when straining against their endstops.