This page details all the acronyms and other words key to understanding the quadcopter hobby. It can be very overwhelming when first starting out, but these should help you understand most of what you need to know! If you still don’t understand anything, be sure to leave a comment and I’ll reply.
Quads and Constituents:
This is your quadcopter (‘quad’, coming from Latin for ‘four’), which has four motors. Multicopters can have any number of motors, and usually have a Latin prefix (Tri, Quad, Penta..)
Sizes: Quadcopters come in all shapes and sizes, and the most standard design is the ‘X’ frame, or a variant of it. A lot of the time quads will be labled as ‘250’ or ‘130’, and this is a (sometimes inaccurate) measure of the distance between the centre of two diagonally opposite motors. You may also see ‘5 inch quad’, which means it can take 5 inch propellers (more on them later).
ARF/ARTF: When you are looking at buying a quad, you will probably see this label, or one of the following three. These basically tell you what state your quad will come in when it arrives. Almost Ready to Fly usually means no battery (or charger), and no receiver/transmitter. Everything else you need is in the box.
RTF: Ready To Fly. This will be completely assembled in the box, and have everything you need to get flying immediately! A great start for a beginner, as everything you need is in one package.
PNP: Plug and Play. The same as ARF, you’ll need a receiver and transmitter (and maybe a battery).
BNF: Bind and Fly. This comes with a receiver, which you can simply bind to your transmitter (providing you have one).
TX: Transmitter. This is your hand held radio, that you use to control the quad.
RX: Receiver. This goes on the quad, and receives the commands you send from the transmitter, telling the quad what you want it to do.
PDB: Power Distribution Board. Most of your components will plug into here, and it is powered by your lipo. However, a lot of days these are built into the FC.
FC: Flight Controller. This is the heart of your quad, and controls everything on board. Usually everything is attached to this, and you can also connect it to your computer to change a lot of options on how your quad flies.
ESC: Electronic Speed Control. These are connected to each motor, and basically control how fast each of them spin, by allowing more or less current from the battery into the motor.
Motors: These are powered by the FC, through the ECSs, and rotate according to your input from the sticks on your transmitter. They are require to spin a certain direction, which can be changed by swapping two of the wires on the ESC over, or reversing the motor direction on your computer.
Kv Rating: All motors have a ‘KV’ rating, which tells you how many revolutions per minute the motor will achieve when 1V is applied. (It’s not actually quite equal to this, but it is a good approximation. If you want to get technical the motor actually generates a back-emf when it rotates, which is proportional to the motor speed, and the Kv constant tells you how they relate, but you can google that for more). The higher the Kv, the faster the motor will spin, giving a higher top speed. However, another important factor is the torque, which basically tells you how much weight the motor can lift. The lower the Kv, the higher the torque. It sounds a bit complicated, but basically 5 inch quads have about 2200-2600Kv, whilst 80mm micros can have 7000-10000Kv, as they are much lighter so don’t need as much torque.
Props: Propellers. These attach to the motors, and are what give your quad the lift to get it of the ground. You can get 2, 3, 4 or more bladed propellers, which is just the number of individual blades on each prop. They are categorised by size, either stating their size in inches (a 5 inch prop creates a circle with a diameter of 5 inches when it spins), or as 5045(X3). Here, the ’50’ indicates a size of 5 inches, with the ’45’ relating to a pitch (a higher pitch means higher thrust, but increased current draw) of 4.5 inches. The ‘X3’ indicates there are three blades on the prop. There are two types of every prop, and it matters which one you put on each motor.
CW/CCW: Clockwise/Counter-Clockwise. This refers to the rotation of both your motors, and propellers. Two (diagonally opposite, usually front left and back right) motors spin CW, and the other two spin CCW. Now, your motors are designed to spin either way, however the threads which hold the props in place with screw-on nuts are not. Really, CW and CCW refer to the direction of the motor thread, which you want to get right. If you have your motor spinning opposite to the thread direction, chances are the nut will loosen mid-flight, an your prop will come spinning off.
FPV and Cameras:
FPV: First Person View. The ‘cockpit’ image from having a camera mounted on your build.
LOS: Line of Sight. This is to fly your quad without an FPV view, directing it by simply watching it in the sky
FPV Goggles: These go on your head, and have a video screen inside them to view your on-board camera feed. You can have the box-type, which have a large screen (usually 5 inch) in the goggles, so are usually very large on the head. You can also get compact-type, like FatSharks, which have two separate screens inside them, and are a lot smaller (but more expensive)
VTX: Video Transmitter. This is what you plug into your on-board camera to transmit the image to your FPV goggles.
VRX: Video Receiver. This plugs into your goggles or monitor (or is built into them), and receives the transmitted camera image.
DVR: Digital Video Recorder. This can be an external unit, or built into your FPV goggles, and will record your transmitted camera image.
These guys power you quad, and FPV goggles if you have them, and are usually made from Lithium-Polymer (also known as LiPo).
Wires and Connectors:
Flight Related Terms: