From the 65" Vyper assembly manual:
Balancing: The Vyper can use a wide range of center-of-gravity locations. For your maiden, we suggest a more forward CG location, since you can always move your CG rearward to suit your flying style if necessary.
For maiden and precision flight - 170-180 mm from leading edge of wing at root
When trimming your CG, keep in mind that a “neutral†CG (one with which you can roll the airplane inverted and the airplane neither climbs nor dives) is good for 3D aerobatics, but a more forward CG (one with which you must hold some “down†elevator to keep the airplane flying straight while inverted) is often
better for precision flight and is much easier to land gracefully.
Control Throws -
Ailerons -
Low Rate 15 degrees 30% exponential
High Rate 30 degrees 70% exponential
Elevator-
Low Rate 15 degrees 30% exponential
High Rate Maximum possible throw, at least 45 degrees 75% exponential
Rudder-
Low Rate 30 degrees 30% exponential
High Rate 45 degrees 75% exponential
Make your first flight with the controls set on low rates. During the trimming phase, we recommend landing with some throttle, and not attempting to “dead stick†the airplane. This may mean you need to time your flights and keep them a bit shorter than usual. After your first flights, check all control connections and motor and prop mounts for tightness.