In the first post in this series, I went through all the parts I ordered to assemble my quadcopter. Everything has arrived and now it’s time to get busy building! The first step is to assemble most of the frame so you have somewhere to attach the rest of the components. The basic principles of a quadcopter frame are the same even if yours is a different model. You need four arms to hold motors, propellers and speed controllers; center plate(s) to hold the battery, flight controller, and receiver; and landing gear or skids to support the quadcopter and take the brunt of the impact on any hard landings.
UPDATE: The wood HobbyKing frame I initially purchased turned out to be really shoddy and weak. One of the arms broke irreparably on one of my first flights. After several iterations of DIY quadcopter frames, I got a DJI Flame Wheel F450 frame which is durable and affordable. The build outlined in this post is obviously based on the HobbyKing frame, but the general steps are still the same as far as the non-frame components go.
The first step for my frame is to attach the four arms to the large center plate and secure them with nylon nuts & bolts. I used a little bit of superglue on each joint as well for added stability.
Next I installed four long nylon screws pointing up on the top of the large center plate. This is where the flight control board will go.
Then, I put the four large nylon spacers on the smaller center plate. This will create the internal space where the battery will rest.
Here’s my frame after I placed the KK2.0 flight control board on the four mounting bolts and popped the small center plate into position below the large center plate. Make sure all the notches in the wood line up so that you have a tight fit and all four of the nylon bolts attached to the lower (small) center plate are sticking up through the larger plate so that you can attach bolts to keep everything together. I tried using the landing gear that came with this frame, but it is extremely flimsy and mine was missing parts needed to assemble it, so I ended up building my own landing gear and getting rid of the included one.
Next step is to attach the motors to the ends of the arms. My frame’s arms came pre-drilled for several different motor sizes so it was easy to attach the motors.
It’s actually starting to look like a quadcopter now!
The next few steps involve soldering connectors on the ESCs to connect them to the motors and making a wiring harness to attach everything to the battery. It is possible to save time by buying ESCs that come pre-wired with connectors but the ones I wanted were backordered and I have a lot of experience soldering so I didn’t mind having to wire everything up myself. You will definitely want to use a heatsink whenever you are soldering anything to an ESC because they can be damaged by too much heat. I bought some of these 3 wire bullet connectors for connecting my ESCs to my motors to keep everything tidy. A small clamp to hold the connectors while you solder the wires to them comes in very handy.
ESC with connector attached:
The next step is to wire up the ESCs to be able to connect to the battery. To do this I attached two ESCs to an XT60 connector, then attached the other end of those XT60 connectors to a third XT60 connector which I soldered on to my battery leads. It isn’t pretty but it will get the job done.
Admittedly, I should have gotten a power distribution board which is essentially a tiny board with a wiring harness built into it. My DIY wiring harness was ugly and heavy so not ideal for a quadcopter, where weight is a critical factor. I’ll be ordering a power distribution board soon and that will be one of my first upgrades. UDATE: I recently got a DJI Flame Wheel F450 quadcopter frame, which has a built in power distribution board and enabled me to get rid of this ugly homemade wiring harness. See my Flame Wheel F450 review.
I attached the ESCs to the arms of the quadcopter with zipties and ran my ugly DIY wiring harness along the sides of the KK2.0 flight control board. The motor wires can be attached to the ESC connectors along the underside of the arms.
Next I attached my receiver to the center plate in front of the flight control board and connected all the wires. If you’re using a KK2.0 flight control board the ESCs should be plugged into the slots along the right side of the board (if you look at it with the buttons on the bottom). The black or brown wire from your ESCs is the ground and they should be plugged in with the ground towards the edge of the flight control board. If you’re using the quad X configuration, then the top-left motor is #1, the top-right motor is #2, the bottom-right motor is #3, and the bottom-left motor is #4. The slots on the left side of the board are for radio channels and should be connected to your receiver, again with black or brown wires facing out. For this control board, only one of the slots needs the power wires attached (red and black/brown) so I removed them from my male-to-male servo leads for the other three channels. I later secured the receiver to the board with a little double sided tape.
The last thing to take care of from a hardware standpoint is the landing gear. The ones included with my frame were really weak so I ended up getting rid of them and building my own out of a 1″ wide aluminum strip I got at Lowe’s. I used a dremel to cut two equal lengths, 16″ each.
To shape the landing gear legs I measured six inches from each end and bent the aluminum over the front edge of a chair. Extremely high tech fabrication process here.
I attached the legs to the bottom of my quadcopter with zipties, using some pre-existing holes in the bottom center plate.
That’s it as far as construction goes. To program my ESCs, I followed the instructions in this post. For setting up the KK2 board in X-quad configuration, I read this post, used the tuning settings from this post, and I was ready for my maiden flight. It’s also a good idea to read the manual.