How to Build a VTOL Drone: Parts List & Step-by-Step Guide

A VTOL fixed-wing drone takes off and lands like a quadcopter and cruises on its wing, which is why mapping teams use it for areas too large for a multirotor. The simplest layout to build and tune is the "4+1" QuadPlane: four lift motors on booms for hover and one pusher motor for cruise. This guide builds an all-electric 4+1 on a 3.5 m carbon airframe, using the propulsion set the airframe maker has matched and tested.

VTOL drone parts list

The table lists every part the build needs, what to check before buying, and matching products. Lift, cruise and servo parts follow the airframe maker's EV350 propulsion kit; where our catalogue carries only a close variant, the row says what to confirm.

Tools you need

• Soldering station with a large tip for 12S power wiring, heat shrink and a heat gun.
• Digital multimeter and a current-limited supply for the first power-up.
• Servo tester, control-surface throw gauge and a digital angle gauge for motor alignment.
• Balance points or a CG scale for the wing, and a laptop with Mission Planner or QGroundControl.

Step-by-step assembly

1. Choose 4+1 over tiltrotor

ArduPilot supports almost any multirotor layout on a fixed wing, including tiltrotors and tailsitters, but the 4+1 is the easiest to build and maintain: the lift and cruise systems are separate, and each can be chosen for its own job. Use a tiltrotor only when the airframe is designed for it and you can test the tilt mechanism under load.

2. Check the weight budget before buying

The EV350 airframe weighs about 6.5 kg and two 32,000 mAh packs weigh 7.0 kg. With a 243 g mapping camera, that leaves about 9.3 kg under the platform's 23 kg rating for motors, ESCs, propellers, servos, wiring and avionics. Write down the weight of every part as it arrives and keep a running total.

3. Size the lift system

T-MOTOR recommends 2.0–2.2 times the take-off weight in static lift thrust for industrial VTOL: at 23 kg that is 46–51 kg, or 11.5–12.7 kg per motor. The P24×7.2 propeller is rated to 15 kg of thrust, which covers it. Mugin reports that the EV350 took off at about 47–49% throttle at just under 20 kg with these lift motors.

The MS8014 lift motors brake to a fixed position after transition, so the stopped propellers sit along the booms instead of across the airflow. That cuts drag in cruise; it is the main reason to use position-locking motors on a 4+1.

4. Plan the battery wiring

The AT7215 pusher is rated for 8–12S, so one 6S pack on its own is below its range; the two 6S packs go in series to make 12S. Confirm the harness layout with the airframe supplier before wiring it. At 22.8 V nominal each, the pair gives 45.6 V and about 1,459 Wh. Use two packs of the same model, capacity and age, charge them as a pair and check each pack's voltage before every flight.

5. Assemble the airframe

Fit the wings, booms and tail with the integrated latches and hardware, and route the wing harness so the connectors cannot be pinched when the wing locks. Mount the lift motors on the booms and the pusher on its mount, then check propeller clearance on every motor through a full turn.

6. Align the lift motors

On a QuadPlane, a degree or two of motor misalignment can remove most of the yaw authority. Block the aircraft level and measure the height of each propeller tip at the front, back, left and right; the difference divided by the propeller diameter gives the tilt angle. ArduPilot also suggests tilting each lift motor 3–5° forward so it is vertical when the wing is at its cruise attitude.

7. Wire power, ESCs and servos

Run the 12S bus to the four lift ESCs and the pusher ESC through a distribution board rated for the combined current, and feed the flight controller through the power module. The PM02D is designed for Pixhawk 5X and 6X controllers and does not power servos.

Power the servos from a separate regulator such as a 3–14S UBEC, or from the AT115A's built-in UBEC once you have confirmed its servo rating at 12S (T-MOTOR rates it for six servos at 6S). Never power servos from the flight controller. Use digital servos: on most controllers the lift motor outputs run at 400 Hz, and a servo on an output group that shares their timer runs at 400 Hz too, which overheats most analog servos.

8. Install the airspeed sensor

Mount the pitot tube in clean air, pointing straight into the airflow, with its side holes at least 1 cm clear of any surface. If a propeller sits in front of it, ArduPilot's rule is at least about 30 cm out on the wing; on a pusher layout, keep it ahead of the nose and away from the lift propellers' downwash. Shield the sensor from light, because many are light-sensitive.

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9. Fit RTK, telemetry and the camera

Mount the ZED-F9P antenna on top of the fuselage, away from the ESCs and power wiring, and the telemetry antennas clear of carbon structure. Fit the camera on a fixed nadir mount in the payload bay, power it from a 12 V regulator if it needs 10–18 V, and wire the trigger and hot-shoe cables as for a multirotor mapping build.

10. Balance the aircraft

Set the centre of gravity at the airframe maker's marked point with the camera and batteries installed, moving the batteries rather than adding weight. A quadcopter can hover with an offset centre of gravity, but the wing cannot fly with one once the lift motors stop.

ArduPilot QuadPlane setup

Load ArduPlane, set Q_ENABLE = 1 and reboot to show the QuadPlane parameters. Set Q_FRAME_CLASS = 1 (quad) and Q_FRAME_TYPE = 1 (X). By default the lift motors go on outputs 5–8 and the plane's control surfaces stay on 1–4. For lift motors on booms running fore and aft along the wing chord, ArduPilot recommends X mixing, so that frame twist helps yaw instead of fighting it.

Connect the airspeed sensor and set ARSPD_TYPE to 8 for DroneCAN. DLVR sensors do not need the power-up zero calibration, so ARSPD_SKIP_CAL can be set to 1; other sensors need the pitot covered when the aircraft powers up. Blow gently into the pitot to check the reading, then enable ARSPD_AUTOCAL and fly a few circuits so the controller can learn the scale factor.

Set the ExpressLRS receiver's serial port to protocol 23 (CRSF), configure the RTK GPS as for a multirotor, and set the battery monitor to read the full 12S pack. Set Q_RTL_MODE to choose whether a failsafe return ends with a fixed-wing approach and a vertical landing.

Transition tuning

When you switch from a hover mode to a fixed-wing mode, the lift motors keep the aircraft up until the airspeed reaches AIRSPEED_MIN, then fade out over Q_TRANSITION_MS (5 seconds by default). Set AIRSPEED_MIN safely above the stall speed. Q_TRANS_FAIL sets a time limit for reaching that speed and is off by default; set it, with a safe Q_TRANS_FAIL_ACT, once the first transitions are logged.

Always transition into the wind. Downwind, the aircraft builds ground speed long before it builds airspeed, and without an airspeed sensor a short downwind transition can end in a stall as the lift motors stop. Do not use Manual or Acro as a bail-out mode on a QuadPlane: both stop the lift motors at once.

Watch the battery during the first transitions. With the pusher at take-off throttle and all four lift motors still working, current peaks and voltage sags; ArduPilot warns that dipping below about 3.0 V per cell can damage LiPo packs or cost lift. If the log shows heavy sag, use packs with a higher C rating, separate lift and cruise batteries, or limit power with BATT_WATT_MAX.

Q_ASSIST_SPEED brings the lift motors back in if the airspeed drops below a set value in fixed-wing flight; Q_ASSIST_ANGLE and Q_ASSIST_ALT add attitude and altitude triggers. ArduPilot suggests flying the first flights with assistance off to tune the airframe, then setting Q_ASSIST_SPEED above the stall speed.

When returning to hover, the pusher stops and the aircraft decelerates on drag and the lift motors. ArduPilot limits the pitch-up at first to avoid a sudden climb, but expect some height gain on the first back-transitions and leave room for it.

Flight test sequence

Hover first in QSTABILIZE or QHOVER with the propellers checked and the wings fitted, and tune the VTOL attitude controller. Then climb to a safe height, switch to FBWA, advance the throttle past half and let the aircraft transition into the wind. Fly circuits to calibrate the airspeed sensor and tune the fixed-wing gains, switch back to QHOVER and land vertically. Run the first auto missions with short legs and a large battery reserve.

Common mistakes

Transitioning downwind. Ground speed hides low airspeed; always transition and land into the wind.

Skipping motor alignment. A few degrees of tilt on the lift motors can make the aircraft unable to hold its heading in a hover.

Using analog servos. Servos that share a timer with the 400 Hz lift outputs need to be digital.

Mixing battery packs. Two packs of different age or capacity in series discharge unevenly, and the weaker pack sets the flight time and the risk.

Mounting the pitot in prop wash. A reading inflated by propeller air can tell the controller it has flying speed when it does not.

For a complete VTOL kit with airframe, propulsion and avionics checked as one system, send the parts list to our team.