The motors, propellers and frame are made of Lego. Non-Lego parts are the battery, radio receiver and flight controller. After building I fly this quadcopter indoors and outdoors. Enjoy!

Drone specs:
Motors (4x): Lego L-motor [88003-1]
Propeller blades (8x): Lego Propeller 1 Blade 14L [89509]
Gearing: 1:1.67 gear-up for each rotor
Frame: Lego liftarms and other Lego parts (look at 11:41 component list)
Flight controller: Matek F411-mini
Motor driver circuit (4x): MOSFET IRLR2905 + Schottky diode 1N5819 + Resistor 12 kOhm (look at 03:57 circuit diagram)
Radio receiver: FrSky R-XSR Micro 2.4GHz
Radio transmitter: FrSky X-Lite 2.4GHz
Battery: LiPo 9s 33.3V 200 mAh (made out of nine Turnigy nano-tech 200mAh 3.7V 35-70C Pico)
Weight with battery: 410 grams
Max thrust: 470 grams
Flight time: about 2 minutes


Betaflight settings diff:
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# version
# Betaflight / STM32F411 (S411) 4.1.1 Nov 15 2019 / 12:55:17 (1e5e3d369) MSP API: 1.42
# manufacturer_id: MTKS board_name: MATEKF411 custom defaults: YES

# start the command batch
batch start

board_name MATEKF411
manufacturer_id MTKS

# resources
# Note: pass telemetry to transmitter (http://www.mateksys.com/?portfolio=f4...)
resource MOTOR 5 NONE
resource SERIAL_TX 11 B03

# feature
feature -AIRMODE

# map
map TAER1234

# serial
serial 30 32 115200 57600 0 115200

# aux
aux 0 0 0 1700 2100 0 0
aux 1 1 1 900 1700 0 0
aux 2 28 1 1300 2100 0 0
aux 3 47 1 1700 2100 0 0

# master
set min_throttle = 700
set min_command = 0
set use_unsynced_pwm = OFF
set motor_pwm_protocol = OFF
set motor_pwm_rate = 480
set align_board_yaw = 135
set pid_process_denom = 16
set gyro_1_align_yaw = 1800