So you’ve looked around at a few drones and you just can’t find one that offers all the features that you’re looking for, that or the price is outrageous.
Why don’t you build your own? It will save you a little money, but it’s still a pricey affair. But you can add all the features you want, program it to fly exactly the way you want it to, and you’ll learn a lot about the mechanics in the process.
For this post, I’ll go over a basic build from parts to flight. I will follow up with an “extras” post next week.
Before we jump into all the electronics and cool tech-ery, lets start off with possibly the most important part of your drone…
The Frame or body, this will be the chassis of your drone, and it will define the overall look of the final product. The frame will also be a deciding factor in the power-plant i.e. the motors, props, and so on.
You can get frame of every different size, they are measured in millimeters diagonally from the farthest motor mount positions. This is a 450 size above, but you can buy frames as small as 150mm or up to 900mm or more. They generally are either plastic, a composite material or carbon fiber and some frames actually house a PDB (power distribution board) inside them. Prices for these can range $10-$300+ for some brand name frames.
Next you’re going to need to get fancy with some electronics for powering and controlling your drone.
Lets talk motors and ESC’s (electronic speed controllers), you’ll need four of each but it’s not a bad idea to keep a few spares on hand in the event of a crash or malfunction. When you’re looking for a motor, you’ll be looking mostly at the KV rating which a round-a-bout measurement of thrust output. The lower the KV number is, the more torque it will output, while a higher number will supply more speed.
In this build, I would go with a trusty ole’ DJI 920KV motor because I have very little issues with these motors and they are really well made.
Moving down the line is the electronic speed controller a.k.a. ESC. These little guys power the motors as well as keep them all timed. They are rated in amps, lower amp esc’s are reserved for low output power systems. This doesn’t mean that if you have a small drone, you should slap on a set of low amp esc’s. It’s all about power here and many small racing drones will use esc’s found in larger drones. For this build, I would go for a trusted name again and rock the Turnigy Plush 30 Amp esc’s.
Now that we have the power-plant all figured out. We need something to control them.
That’s where the Flight Control Board comes into play. Refereed to as a FC in the lands of forum speak, this small computer chip is the entire brains of the operation. All the motors and escs are connected to the FC, as well as pretty much everything else. There are tons of different FC boards. Choosing one is very important though so take your time with this. Any “extra” add-on you might like to install might be reliant on this board. For example, if you want to install GPS on your drone, make sure that the FC supports GPS input. Another thing to watch is, while many might allow GPS input, if you plan on using GPS guided flight, the board must support it. There are so many options here, so once again, just read carefully. For this build I’m keeping it simple, I’ll use a CC3D board, because I am familliar with it, and when calibrating it, I can connect it to my computer or phone and easily configure things.
You’re also going to need a reciever…which with either be bundled with a transmitter (Remote controller you’ll use to fly) that you buy, or you’ll buy an upgraded one. The receiver will be mounted on the drone and it is what receives your commands from the ground. There are too many options here, and this will depend on the frequency you want to transmit from, and the type of communication. I wont delve too far into this but match things up, if you buy a transmitter that operates on 2.4Ghz and uses DSMX, then make sure your receiver is also 2.4Ghz and uses DSMX. To play it safe and save yourself a lot of trouble, just buy bundled.
Ok so now you need to bring the drones power system to life. And what better way to do that than with a Lithium Polymer battery, or LiPo for short. These batteries will have tons of different numbers on them when you start looking around.
What the heck is a 2-cell 7.4V 30C 2200mAh? Ok I’ll try not to get too deep here. Batteries will have a certain number of cells. With drones youll be somewhere between 1 cell and 6 cells. The number of cells and the “V” voltage are one in the same. a 1 cell battery is 3.7 volts, and a 2 cell is 7.4 volts, and the voltage continues to progress with cell numbers. The 30C in the above example refers to the discharge rate, a higher discharge number will be able to output a LOT of power in a short burst but will drain quicker. This comes into play with the ESCs from before, if your “C” rating is too much for your esc to handle, they will likely blow. The 2200mAh refers to the capacity or the “fuel tank” of the battery. A high number will give you more “fuel” but simply adding a battery with 6000mAh isn’t going to make it fly all day, the added weight of a battery that size will make the drone spend more energy keeping its self in the air. For my purposes Ill use a 3-cell 11.1V 3000mAh 30C battery.
You’ve slapped all your parts together, you’ve configured the flight control board, and you’re ready for the maiden flight of your first DIY drone. Power that bad-boy up and give ‘er full throttle. The motors scream at full speed but it doesn’t go anywhere…
Well we haven’t gone over propellers yet! You were just going to put some one there and go for it weren’t you!?
Using the right props is key to a good flight. Props come in different materials, which at first seem like a flashy “bling” statement. But those different materials have major differences in flight characteristics. Don’t be “that guy” and buy carbon fiber props because they look “sweet” , especially if you are a new pilot. Do yourself a favor and get some cheap plastic props to begin with and make sure to get multiple sets. Spend time researching props before you buy expensive ones. Ok so now to the prop size. You’ll likely come across adds that say something like 9050CW/CCW and with props the first two numbers are related to total length of the prop in this instance the “90” stands for 9-inches, the last two numbers are related to pitch and in this instance the “50” stands for a 5-inch pitch. The easiest way to describe pitch would be, if you were to turn the prop one full cycle it would travel “X” number of inches through a piece of wood or foam. The lettering may be obvious to you, but CW stands for Clock-wise, and CCW stands for Counter Clock-wise. You will need two CW and two CCW props for flight.
Your props will depend on the size of your drone, as well as the motors you chose. If you chose a higher KV motor, you may want to consider a 9-inch prop. Conversely if you chose a motor with a lower KV rating feel free to try 11 or 12 inch props. For my build I will use a set of 1045CW/CCW props. 10-inch length and 4.5-inches of pitch.
Alright, now you should be ready to fly! You’ve got a frame, motors, escs, flight control board, receiver, a battery, and props! Be cautious of your surroundings and try not to lose it. Get some practice in with it and enjoy flying it, because my next post will be about the upgrades that can make your flight experience amazing!