Getting a quadcopter stable in the air isn’t trivial. Stability of a quadcopter relies on the harmonious working of all of it’s parts.
An unbalanced propeller produces excessive vibration. This vibration travels through the entire airframe affecting the handling of the aircraft, produces inaccurate readings by the sensors, and creates premature failure of motor bearings and parts. A balanced propeller is paramount to a stable aircraft. A balanced propeller produces less vibration and draws less current, which results in greater stability and extended flight times. You should balance any propeller before installing it on your aircraft. Balancing a propeller requires the use of a special tool, you guessed it a propeller balancer. The propeller balancer that I use is the Top Flite Propeller balance. It is essentially a shaft held by two magnets. The magnets create a frictionless surface for the shaft to spin freely. Read More…
Power connectors come in various of shapes and sizes. Choosing a power connector is dictated by power requirements and compatibility. The most common power connectors are XT-60, Deans Ultra Plugs and EC3 and EC5 Bullet Connectors.
I use the Deans Ultra connectors but I found they can lose contact when fully plugged in. This is an inherent design flaw with the T type connector. I would choose the XT-60 connector if I was not so invested in the Deans connector. I favor the XT-60 because they are easier to solder and connect and disconnect with ease.
The R/C radio controls the throttle and the direction that the quadcopter travels. When choosing an R/C radio, the most important feature is how many channels the radio supports. One channel independently controls one servo or ESC. The more channels, the more devices that can be independently controlled. The minimum number of channels for a quadcopter is 5. Four of those channels are for the four motors and the other channel for switching between flight modes. These flight modes could be switching from stable or acrobat mode or to enable or disable autonomous flying. A radio with more than 5 channels will allow auxiliary devices to be controlled. Some devices that could be controlled are lights, robotic cameras or landing gear.
For Scout to auto-stabilize, it needs sensors to find its orientation in space. No one sensor can do this on its own. It takes several different sensors working together to calculate Scout’s orientation. The sensors used to calculate orientation are gyroscopes and accelerometers. More recently, magnetometers are being incorporated to calculate direction.
Conveniently, there are boards that incorporate all of these sensors together. These boards are called inertial measurement unit, or IMU. An IMU uses accelerometers and gyroscopes to measure and report the aircrafts velocity, orientation and gravitational forces on multiples axis.
Scout uses the ArduPilot Mega IMU shield. I chose this board because it was developed to work with the ArduPilot Mega board.