02
First Flight & Servo Setup
Center the wings, set the correct directions, tune endpoints and survive the maiden flight.
1 · Centering the servos
Power the receiver with the radio bound but sticks neutral. Every servo must sit at 1500 µs. If a horn is not perpendicular to the linkage, unscrew it and re-seat it on the closest spline — never force the neutral with sub-trim on the radio; the flight controller already assumes a true 1500 µs centre.
The wing pair is the critical one: both wings must be at the same geometric angle at neutral. A half-tooth difference between left and right is visible as a roll bias in flight and cannot be trimmed away by the gyro without eating into its authority.
2 · Direction & reversing
| Stick | Expected surface |
|---|---|
| Roll right | Right wing tips up, left wing tips down |
| Pitch up (pull) | Both wings tilt to raise the nose (or elevon equivalent) |
| Yaw right | Crest rudder deflects right |
If a surface moves the wrong way, reverse it in the flight controller config (the servo kernel direction flags), not by flipping the servo or using a radio channel reverse that shifts the 988–2012 µs map. Keep the radio output symmetric around 1500 µs.
3 · Endpoints & limits
The servo kernel defaults to servoMinUs 988 and servoMaxUs 2012. Set mechanical endpoints so the wing sweeps its full travel without binding at the extremes. Listen for the buzz of a stalled servo — back off the endpoint until it stops. Endpoints live in the servo kernel, not in the radio: leave the radio at ±100%.
4 · Pre-flight checks
- Wings centred at neutral, both directions correct.
- Endpoints set with no stall buzz.
- Failsafe verified — transmitter off — wings and rudder centre.
- Gyro responds in the correct sense (roll the airframe, rudder should oppose).
- Battery voltage matches the BEC rating; servos do not brown-out on a full sweep.
5 · The maiden flight
Hand-launch into a gentle glide first, motor/flap off, to confirm trim and balance. Only when it glides straight should you engage a low flap frequency and low ferocity. Increase frequency slowly; resonance and aeroelastic effects change with airspeed, so re-trim after each change. Land early on the first battery — the goal is data, not duration.