- Getting Started
- FPV Intro and Brief History
- Quad Components
- Electronic Speed Controller (ESC)
- Flight Controller
- Battery Chargers
The quickest, cheapest and safest way to get started if you’ve never flown Radio Control (RC) before is buying a micro-quadcopter. For under $100 you can get a Ready-To-Fly (RTF) that comes with built-in camera, radio, battery and charger. Most models are safe for indoor flying and kids. Even for adults it’s a great way to learn how a radio controls a quad, and have a lot of fun! Before, during or after enjoying your “micro”, you can practice on your computer via a free or inexpensive flight simulator.
Once you have your sea legs (or air thumbs in this case), a next progressive step could be a get a bigger, and modestly priced RTF. If you are already skilled with hand-ons electronics and components, and cost isn’t a big inhibitor, you could even jump in with both feet and build your own high-end racing quadcopter. There’s endless options depending on your experience, confidence and pocket book!
FPV is an abbreviation for First Person View. It began years ago when a few people attached small security cameras to model airplanes and model helicopters. This gave the user the ability to “remotely” sit in the cockpit of a small model aircraft and essentially see out of the windshield. Several years later, the fundamentals of FPV are the same.
The FPV system is made up of four major components. The first component is the camera that is usually mounted on the front of an aircraft which allows you to see in front of it. The second component is the video transmitter. It sends your video signal back to the receiver on the ground from the aircraft. The third component is the video receiver. This component receives the transmission from the transmitter that is on the aircraft. The fourth component is the display. This component comes in many variations of goggles, FPV monitors and display screens. Goggles give you the most immersive feeling compared to a monitor or screen.
A quadrocopter, a.k.a "drone" is one of the most popular aircraft to carry FPV equipment today. When deciding to build your own drone, the airframe is an important factor. The size and shape of the “frame” dictates what electronic components you can use.
Essentially there are two systems on a drone. The propulsion system and the FPV system. There are three main electronic components that work together for propulsion. Motors receive power from the Electronic Speed Controllers (ESCs) and spin the propellers. The propellers are typically the only moving components on your drone.
The Electronic Speed Controller (ESC) component supplies the motor with the energy needed to spin the motors. It also communicates directly with the flight controller. This communication is essential for a successful flight and operation of your drone. It works by adjusting the speed of the motor to keep the aircraft level in flight. For example, if you are taking a left turn, the left side motors slow down and right side motors speed up.
There are many ESCs on the market ranging from 10 amp up to 80 amps. Many of them have different processor chips and firmware. A faster processor brings faster communication between the ESC and the flight control board. Faster communication means better performance. The most common firmware that is on most ESC's is SimonK, Blheli, and Multishot. All of these offer unique characteristics.
The flight controller essentially is the brain of the aircraft. The flight controller dictates flight characteristics and receives signals from your transmitter. It then relays the processed information to the ESCs. Most flight controllers offer different modes for flight controls. One example is auto level which uses the accelerometer to keep the aircraft level in flight. Many pilots prefer rate mode that solely relies on the gyro for operation. For those who are looking for return home and waypoint options this platform is most common on Aerial Photography (AP) drones like the DJI Phantom.
Frame selection is extremely important. If you’re main interest is aerial photography, you probably want a 400 plus size frame. The size of a frame is determined by the distance diagonally between the motors. If you plan on racing, 180 to 250 size frames are most popular. Frames are made out of many different materials and shapes, the most common today is carbon fiber. Carbon fiber offers many characteristics that are beneficial for building a light strong frame. When selecting a frame you want to look at the quality of the carbon fiber.
Some frames have detachable arms which makes it easy to replace a damaged arm. A unibody frame requires you to replace the whole bottom plate if one arm breaks. All styles of frames have pros and cons. In the end it all becomes personal preference. You will notice different flight characteristics for each frame.
There are many different propellers on the market today. The best way to understand the difference between propellers, is to learn how to read the numbers that the propellers use to differentiate themselves. For example, a common propeller size today is a 5040pc. 50 represents the prop length, which in this case is a 5 inch propeller. If it was a 6 inch prop the number would change to 6040. The next number 40 represents the angle of attack or the pitch angle of the propeller. This number is extremely important too. The lower the number the less thrust you will have, but you’ll gain efficiency (impacting battery charge duration). For example, a 5040 prop may have a flight time around 5 minutes. If you were to switch to a 5050 prop you would notice an increase in power but a decrease in flight time.
Now we have the basic understanding of the numbers, let's talk about the letters. PC is an abbreviation for the material used to manufacture the propeller. In this case PC stands for polycarbonate. PC has its own unique characteristics it remains rigid yet still flexible. Nylon is also a popular material used in propellers this material does not offer a lot of flex. Some people prefer this material over PC because it's hold its shape under high RPMs. A example of this would be like putting stiff shocks on a sports car. It holds tight around corners and doesn't bounce. The downfall of a stiffer prop is that they usually break during crashes. Unlike props made of a more flexible material.
Beyond the materials, there are several styles of props: two-blade, tri-blade, and quad-blade. All three have different flight characteristics. Two-blade props offers higher top end speed but lack some control characteristics. For example if two identical quads are racing, one with two-blades and one with tri-blades, the two-blade prop would have an advantage on a big course with long straight aways. If it was shorter course and more technical the tri-blade prop would have an advantage due to the ability of handling corners better, as well as better low-end power. The quad-blade props are more commonly used in aerobic flying because of the low end power and super tight handling. The top end power of four blade props is sacrificed for the feel of stability. Less blades also is lighter and therefore better flight time efficiency. A good analogy would be canoeing. One paddle would allow you push yourself through the water fairly easy without exerting a lot of energy. If you were to increase the size of the paddle or use a paddle on each side, you would be able to move more water and propel yourself faster. The downside is you would exert much more physical energy.
To sum it up a two-blade propeller offers more top-end power and less control. The tri-blade propeller has less top end and more control. When it comes time to select a propeller you also need to take an account the size and KV of your motor and what kind of flying you would like to do. Try several combinations and find what feels best for you.
A very popular motor for quad racing right now is the 2206-2350KV. The first two numbers (22) denote the diameter of the stationary part of the motor, called the stater. The next two digits (06) is the height of the stater. The stater typically has copper windings that create the KV of the motor. With these components combine along with the strength of the magnets determines the amount of power the motor will produce. Keep in mind more power means more amp draw. For example if you have a motor that draws 20 Amps you'll need to pair it with an ESC that is capable of pushing 20 Amps.
The FPV Camera is a critical part of your FPV system. The quality you seen in your goggles is limited by the data your camera can collect. The most commonly used cameras these days are CCD and CMOS. The biggest difference between the two is the way the process light. The CCD camera can switch from dark to light much faster than CMOS. For example if you were to fly up at the direction of the sun, the CMOS would white out and you would not be able to see until you change directions. The CCD camera will hold the image much better in light to dark situations. The CMOS offers sharper image and more vibrant colors but lacks ability to hold image in dark to light situations.
Many FPV cameras have an exchangeable lens. Some have a narrow field of view, like the 2.8 lens (focal length of the lens in millimeters). This is typically the standard lens that comes with cameras. If you're looking for a wider field of view, try a 2.5 lens. You could also go all the way to 2.1. They are inexpensive and easily changed.
When selecting your battery you need to keep a couple things in mind. The number of cells, the Maa rating and the C rating. Each cell per pack represents 3.7 volts. For example a 3 cell will total 11.1 volts. The Mah reflects the capacity and size of the battery. A 2200mah would be much larger than 1300mah battery. A larger mah rating does not mean longer flight time. The battery that is too large will result in the less flight time due to it’s weight requiring the motors to work harder to keep it in flight. The C rating is how fast the battery can discharge energy without getting damaged. Also keep in mind you can't run the LIPo battery until it dies. When your battery falls below 3V your cells will most likely get damaged. The chemistry will be unstable and can become very dangerous. With that being said safety should always be a high priority.
Your battery charger is one of your most important investments. It will outlast many batteries and most of your gear. When selecting a charger you want to make sure that it fits your needs. There are relatively cheap chargers on the market they can charge one battery at a time. If you're in it for the long-haul, you’ll have a lot of batteries and want to charge many at the same time. A digital high output charger is recommended. Most chargers on the market today offer balancing which is very important for LiPo cells and battery life. When your parallel charging its very important to be able to select charging current, battery type, and power output. Not all chargers come with their own power supply. The power supply must match the demand of the charger. One more option to keep in mind is the ability to cycle new packs before use. By doing this you insure the the battery reaches it full potential.