A presentation held at SAPO CodeBits 2010 (http://codebits.eu/intra/s/session/114), describing the operational theory and basics as well as the building blocks of a remote-controlled model quadrocopter. A video of this talk can be found here: http://videos.sapo.pt/HZSIm9FUl3D3bfqmVcsv

1. How to build your own QuadrocopterHow to build your own Quadrocopter
Lenz Grimmer <lenz@grimmer.com>
http://www.lenzg.net/
Twitter: @lenzgr
SAPO Codebits 2010, Lisbon, Portugal

2. OutlineOutline
● Basics / Operational Theory
● Building Blocks
● References/URLs
● Demo

3. FeaturesFeatures
● A “VTOL UAV”
● Simple to build
● Simple mechanics
● No servos required
● Parts Availability / Accessibility

4. Lab/Tech RequirementsLab/Tech Requirements
● Soldering station
● Powerdrill / Dremel
● Others (Screwdrivers, Saws, Files)
● Power supply

5. Operational theoryOperational theory
● Physics
● Flight Dynamics
● Movement / Control

6. PhysicsPhysics
● 2 pairs of counter rotating props
● Compensate rotary momentum
● Different RPMs = different thrust

7. Flight DynamicsFlight Dynamics
http://en.wikipedia.org/wiki/File:Flight_dynamics_with_text.png

8. Movement/ControlMovement/Control
● Regular remote control
● Behaves like a helicopter
● Nick / Roll / Yaw
● Up / Down
● “X”, “+” or “Y” flight configuration
● Pilot skills

9. Momentum CompensationMomentum Compensation

10. Yaw/RotationYaw/Rotation

11. Vertical MovementVertical Movement
F F
FF
m·g
4⋅F=m⋅g
4⋅Fm⋅g
4⋅Fm⋅g
Ascending
Descending

12. Nick/RollNick/Roll
F1 F2

13. Nick/RollNick/Roll
F1
F2

14. Building blocksBuilding blocks
● Frame
● Motors
● Propellers
● Battery
● Electronics

15. FrameFrame

16. FrameFrame
● Center plate
● Arms
● Battery mount
● Motor mounts
● Protective dome
● Landing gear

17. PropellersPropellers

18. PropellersPropellers
● Diameter: 8, 10, 12 inch
● 2 blades
● Directly attached to motor
● 2 each rotating CW and CCW
● Proper balance reduces vibrations

19. MotorsMotors

20. Brushed MotorBrushed Motor
+ -

21. Brushless MotorBrushless Motor
Phase A
Phase C
Phase B

22. MotorsMotors
● Brushless
● Outrunner vs. Inrunner
● Direct drive (no transmission)
● 3-phase powered
● Requires special BL controller
● Weight (g) / RPMs/V / max. current (A)

23. Brushless ControllerBrushless Controller

24. Brushless ControllerBrushless Controller
● Converts DC power to 3-phase AC signal
● Drive motor to indicated RPMs
● Controller speed is essential
● Receives RPM info from receiver/control unit
● PWM signal
● I2C
● UART (Serial)

25. BatteryBattery

26. BatteryBattery
● Lithium Polymer (LiPo) (or Lithium Iron
Phosphate, LiFePo4)
● Lightweight
● High currents and capacity
● Handle with care!
● Voltage / Capacity / Max discharge /
Weight

27. Power Distribution / WiringPower Distribution / Wiring
Battery
Motor
BLC
Sensors
Motor
BLC
Motor
BLC
Motor
BLC
RX
Central Control

28. Power DistributionPower Distribution

29. Power DistributionPower Distribution
● Supply the BLCs / Motors
● Supply the central controller / Sensors
● Support high currents
● Main switch or battery plugs
● Wires or PCB

30. Transmitter / ReceiverTransmitter / Receiver

31. Transmitter / ReceiverTransmitter / Receiver
● Frequencies: 35/40 MHz, 2.4 GHz
● Minimum: 4 channels
● Receiver output: PPM (sum signal) or
individual channels from receiver
(PWM)

32. SensorsSensors

33. SensorsSensors
● IMU
● Gyroscopes (Rotation)
● Accelerometers (Movement)
● Optional
● Pressure Sensor (Altitude)
● Compass/Magnetometer (Attitude)
● GPS (Location)

34. Central ControllerCentral Controller

35. Central ControllerCentral Controller
● Collects sensor data
● Receives control commands
● Calculates orientation/location
● Sends updated motor commands to
BLCs
● Microcontroller (e.g. Arduino, ARM...)

36. Configuration SoftwareConfiguration Software

37. AccessoriesAccessories
● Camera mount
● Zigbee for telemetry data
● Video goggles

38. Legal aspectsLegal aspects
● Check local laws for regulations
● Consider getting an insurance

39. Practical tipsPractical tips
● Double-check propeller positions and directions
● Double-check Flight Control orientation
● Avoid vibration where possible for stable flight
● Test outside, away from people
● Don't attach the propellers on the motors until
everything is tested!

40. References / URLsReferences / URLs
● Forums
● RCGroups - http://www.rcgroups.com/
● DIYDrones - http://diydrones.com/
● Portuguese Forum - http://forum.rcmpt.com/
● Projects
● Mikrokopter - http://www.mikrokopter.de/
● UAVP-NG - http://ng.uavp.ch/
● Arm-O-Kopter - http://www.armokopter.at/
● Arducopter - http://code.google.com/p/arducopter/
● Aeroquad - http://aeroquad.com/
● KK-Multicopter - http://kkmulticopter.com/
● OpenPilot - http://openpilot.org/
● Quadrocopter and Tricopter Info Mega Link Index
http://www.rcgroups.com/forums/showthread.php?t=1097355

41. References / URLsReferences / URLs
● Parts
● HobbyKing -
http://www.hobbyking.com/
● SparkFun - http://www.sparkfun.com/
● DIYdrones - http://store.diydrones.com/