Multicopters are now very popular with the FPV community. The leading companies in FPV community, like DJI, Parrot and 3D Robotics, are all manufacturing and selling multicopters.
A MULTIROTOR OR MULTICOPTER IS A ROTORCRAFT WITH MORE THAN TWO ROTORS. AN ADVANTAGE OF MULTIROTOR AIRCRAFT IS THE SIMPLERROTOR MECHANICS REQUIRED FOR FLIGHT CONTROL. BECAUSE OF THEIR HELICOPTER LIKEFLIGHT CHARACTERISTICS, MULTI-COPTERS OFFER A TOTALLY DIFFERENT EXPERIENCE TOPLANES. UNLIKE SINGLE- AND DOUBLE-ROTOR HELICOPTERS WHICH USE COMPLEX VARIABLEPITCH ROTORS WHOSE PITCH VARIES AS THE BLADE ROTATES FOR FLIGHT STABILITY ANDCONTROL, MULTIROTORS OFTEN USE FIXED-PITCH BLADES; CONTROL OF VEHICLE MOTION ISACHIEVED BY VARYING THE RELATIVE SPEED OF EACH ROTOR TO CHANGE THE THRUST AND TORQUE PRODUCED BY EACH.
The ability to slowly approach a subject,hold its position and turn on its own axis opens the airframes up to lots ofcircumstances a plane can not cater for. If you have not flown a helicopter orplane before it is probably the hardest of all disciplines to learn as abeginner. Multicopters are very varied in build, configuration and control.
Due to their ease of both construction andcontrol, multirotor aircraft are frequently used in model and radio control aircraft projects in which the names quadcopter, hexacopter and octocopterarefrequently used to refer to 4-, 6- and 8-rotor helicopters, respectively.
The Quad Copters are extremely popular. It is a multirotor helicopter that is lifted and propelled by four rotors. Quadcopters are classified asrotorcraft, as opposed to fixed-wing aircraft, because their lift is generatedby a set of rotors (vertically oriented propellers).
With 4 legs as the name suggests they require no yaw mechanism. They are available in two layouts a + configurationwith the front leading leg being straight ahead, or the much more popular andFPV friendly X configuration with the two leading legs being 45 degrees to theleft and right of the front of the platform. The platform is very stable whensetup well, it can be very acrobatic too compared to the Tri Copter. Becauseits symmetrical most pilots have different coloured front legs to back to aid orientation.It is very good at carrying a decent amount of payload, and flight times can be15 mins + at times, but 6 – 10 normally depending on weight, motor and propchoice.
Unlike most helicopters, quadcopters use 2sets of identical fixed pitched propellers; 2 clockwise (CW) and 2counter-clockwise (CCW). These use variation of RPM to control lift and torque.Control of vehicle motion is achieved by altering the rotation rate of one ormore rotor discs, thereby changing its torque load and thrust/lift characteristics.
Generally the more rotors, the more motors,the more stable and the more you can carry in weight.