Determine Your Copter
Building a custom copter can be a lot of fun and gives you the flexibility to add to it later with cameras and other creative improvements. Not only will creating your own helicopter save you money, it will also give you the knowledge to be able to improve upon it or even make another. This article will lay out, step-by-step, the parts and directions needed to build your own. Please keep in mind that most of this tutorial is based on personal experiences.
How Many Arms Do You Need?
To start out, you should first determine what you'll be using your copter for. Because the amount of arms, length of arms, and size of motors and other hardware matters when making this decision, you should first figure it out, not to say one can be used for the other, because they better optimize the performance of the machine. Incase you're not sure what you need, you can use these loose descriptions of each copter style:
Filming: If you plan to use your helicopter for recording, you might want to optimize it for stability for smooth playback. For this reason, longer arms and slightly slower Kv motors are recommended. In order to achieve reduced stress on the parts (which you'll want if you plan to haul a heavy camera), you should consider having more arms (six arms = hexacopter, eight arms = octocopter). Whether you're building a tricopter or an octocopter, the procedure is relatively the same.
Stunts: While I don't recommend this setup for beginners, some people will prefer a more compact and lightweight copter setup for better maneuverability to easier do stunts with. How many arms you have on your copter is purely personal preference, however, a lot of people like tricopters for stunts as they have a servo mechanism that allows for faster yaws (change in orientation).
Hobby: As a hobby-focused copter, you don't have to focus on a specific design or parts. You also won't be limited by those factors.
This tutorial will assume you're using it for personal enjoyment, or as your hobby, but I'll be using a Compact Copter design.Your parts don't have to match the ones I chose to use for my build. That's the great part about building your own -- you build it to your liking!
Optional Step: Design Your Helicopter
I recommend designing your helicopter in a computer aided design (CAD) software such as Sketchup (free). However rough the 3D model, it doesn't really matter; it only matters that you can convey your thoughts in a visual manner so that you can plan out your thoughts and so other people who are helping you (if any) can see your thoughts laid out. Read through this tutorial and, if you feel capable and the need to, have a try at designing your own helicopter in Sketchup, like I have (picture below).
Helicopter Design In Sketchup
You'll need some parts to start out your build. Depending on how many arms you want your multi-rotor helicopter to have, your list will vary. Here is a generic shopping list for my tricopter:
- Frame (I'll be using the Compact Copter)  $49.99
- Transmitter  $139.99
- Receiver (comes with transmitter)  $29.99
- Battery (5000 mA)  $49.65
- Flight control board (KK2.0)  $29.99
- Power distribution board  $3.99
- Propellers (can't have too many)  $12.00
- Electronic speed controller (ESC) x number of arms  $38.97
- Motos x number of arms  $28.44
- Servo  $7.99
- USBasp AVR Programming Device (to upgrade KK2's firmware)  $4.95
- Bullet connectors  $3.32
- Prop balancer (optional)  $5.70
- Servo tester (optional)  $6.25
- Dean's connectors (optional) [x] $7.95
If you want to see a list of links to the parts that I ordered, click here.
In total, this list adds up to just over $300. You could skip the servo tester if you wanted to get closer to $300, but everything else is pretty necessary to get in the sky. If you're not looking to spend as much, check out this great multi-rotor copter RTF with camera (here's a video review) for only $100 (keep in mind this comes with the transmitter and a camera, so it's a great buy). Otherwise, start placing your orders because HobbyKing likes to take their time in shipping. I recommend you bookmark this page for later reading.
Update & Balance
Once you've finally received your parts in the mail (it will seem to take forever) and before you start rigging your frame and flying, you should update your board, balance your propellers and motors, and, what's known as, flash your ESCs (if available). These three updates only need to be done if they've updated the firmware of your board or you break a part/prop. Though it isn't necessary, I highly recommend updating the your hardware and balancing your props in order to maximize the stability and response of your helicopter.
- Updating The Board's Firmware
To start out, upgrading the flight control board is pretty easy and it usually adds a lot of improvements, so you should try to update your board when each update is released.
- Plug in the 6 pin USBasp connector to the 6 pins located left of the buttons and connect it to your computer.
- If the board doesn't turn on, you have it plugged in the wrong way
- The drivers will fail -- click this link to download the corresponding drivers
- Extract the zipped file and pay attention to where it is located on your computer.
- Navigate to Control Panel -> Devices and Printers -> USBasp -> right click -> properties -> hardware (tab) -> Properties -> Update Driver... -> navigate the folder you just downloaded -> finish up and close the windows.
- Download the flash tool(scroll down to downloads and download the latest KKmulticopter flash tool)
- Extract the zipped file and pay attention to where it is located on your computer.
- Download and install Java
- Open the flash tool
- Programmer = USBasp
- Port = USB
- Controller = Hobbyking KK2
- Select the newest firmware update for the KK2.0 from the dropdown list (the author should be KapteinKuk).
- Click the green button on the right side of the screen to start flashing.
- You will get a confirmation message when it's done (it should take less than a minute).
- Flashing The Electronic Speed Controllers
Flashing, or updating the firmware in, the ESCs is definitely an improvement that should be considered. It requires a makeshift adapter or a $20 cord from HobbyKing and a little bit of surgery on your ESCs to do, but flashing it can improve the motors' response time and efficiency. As I am not going to flash my ESCs, I will redirect you to this post and this wiki if you're interested in doing it (I would, but mine aren't compatible with the SimonK flash).
- Balancing Your Propellers
Balancing your props is a crucial part in preparing your helicopter for flight. It reduces vibrations and simply helps the overall performance. You'll need your props, two cups (of the same size and made of a smooth material), and some sandpaper.
- Put a prop on the prop balancer.
- Put the props between the two cups and determine which side is heavier (the heavier side will fall).
- Sand the heavy blade on the bottom side.
- Careful not to sand too much -- check the balance frequently.
- Also avoid sanding the leading and trailing edges of the blade.
- While they are horizontally balanced, the center part might not be balanced, so orient the blade vertically and determine which way it falls -- the side it falls toward is heavier, so sand it some. Alternatively, you can add a bit of glue to the other side to counter the weight, but I prefer the sanding method as to minimize air resistance.
- Now your blade should hold still however it is oriented on the cups.
- Balancing Your Motors
This step is a little more difficult due to the sensitivity and difficulty in assessing the weight distribution. You'll need to connect the motor to your ESC and board (see below) and screw it down to a solid position. Now, there are two methods of balancing the motors:
- Use the free iSeismomotor app to determine the shake.
- Put tape on the motor, and repeat the process. If it is worse, move the tape around the motor. When you find the spot that lessens the vibrations, add tape until it diminishes the performance. You can see this process in the third video below.
- Mount your motor onto a ruler using zip ties or tape, tape a mirror beside the motor (on the ruler), and shine a laser light into the mirror, bouncing it onto the wall (further distance = more precise measurements).
- Put tape on the motor, and repeat the process. If it is worse, move the tape around the motor. When you find the spot that lessens the vibrations, add tape until it diminishes the performance.
Once complete, your new pieces are balanced, updated and ready to mount!
Update KK2.0 Firmware
Simple Prop Balancing Technique
Rigging Your Build
If you like building things (you probably do if you're reading this), then you should really enjoy this next step! You're now ready, with all components at hand, to rig your helicopter. If this is your first time building something like this, don't worry, it's not difficult. The design you (may or may not have) made earlier should help in setting up the body. Once you have the placement figured out for your own copter and have soldered the pieces together, your next and final step is to set up and connect your KK2.0 flight control board (the brains of the operation). This manual provided by Hobby King is very helpful in explaining what each function does and the initial setup. From here, it is a matter of fine tuning your settings to get the perfect flight. Now you're in the air -- have fun!