High-Performance Quadcopter for $120 – Part 2: The Build
If you’ve been following Step 1 of our series, you now have a series of silvery plastic bags, and a cardboard box with some frame parts. Now what?
Thankfully, the build is very easy and not difficult at all.
Part 1: The Shopping List
Part 2: The Build
Part 3: Flashing and Setup
Let’s start with…
Step 1: The Frame
The frame consists of a lower plate, and upper plate, and four colored arms. Many people put the white arms in front, others have the white arms as rear arms. In the end it’s up to your personal preference. For the purpose of our build we’re keeping the red arms pointing forward, the white arms point rearwards. Use the supplied screws to connect the arms to the plates. With this small copter you can assemble the complete frame, there’s very little we need to put inside except the battery.
The frame parts as they come out of the box. You’ll also get a bag of screws and an assembly manual.
The finished frame. It’s ok to complete the assembly right away.
Step 2: Solder ESC connectors
Next we solder the 3.5mm bullet connectors to the three motor output wires of the ESCs, as well as the two 2mm bullet connectors to the power input leads of said ESCs. As you can see on the pictures, the female 3.5mm connectors are used at the ESC outputs. Since our power distribution cable features all-female outputs as well, we’ll solder the two male 2mm connectors to the power inputs of the ESCs. Just pay attention when connecting the ESC to the power distribution cable and you’ll be fine. Put heatshrink tubing over the soldered connectors, making sure all conductive areas are well covered. If you use a lighter to heatshrink the tube, make sure not to apply too much heat, or you’ll risk making the tubing material soften and melt.
This is where our connectors go on the ESC. Note the two male connectors on the power leads. The star-shaped cable on the right is our power distribution cable.
Always pre-heat the connector before adding solder. Make sure the solder permeats the copper of the cable. It’s not worth losing a model due to a hastened solder job.
The end result. Now rinse and repeat three more times.
Step 3: Motors
The same thing as on the ESC now has to be done for the motors. Solder on the male 3.5mm bullet connectors and put heatshrink tubing over the result. Use the supplied motor screws to fix the motor on the frame. Depending on your parts bag you may be fine with the supplied screws, or you might have to get longer screws.
The bullet connectors on the motors. Don;t forget the heatshrink tubing!
Screw the motors onto the frame. The photo shows the final result with propeller installed, but we advise you to keep the props off for now.
Step 4: Wiring and Flight Controller
Now the fun part: Connect the four ESCs to the motors, and hide the power distribution cable inside the frame. We’ll slide the battery underneath that cable. You might have to turn the ESC to sling the excess cable length around a bit. Note that shortening the ESC leads is not recommended. You can shorten the power leads however, if you want.
The power distribution cable goes inside the frame. We recommend to have the battery connector stick out at the rear end.
The motors about to be connected to the flight controller. Motor 1 is top left, Motor 2 is top right, Motor 3 is bottom right, Motor 4 is bottom left. The connectors for the motors are on the right side of the flight controller.
The flight controller is easy to connect: Motor connectors are on the right side, inputs from the receiver are on the left. Connect the four motors to the controller outputs, with motor 1 being the top left one, motor 2, 3 and 4 following clockwise.
The inputs and outputs of the KK2 flight controller.
Stick the flight controller to the frame with double-sided sticky tape.
Use zip-ties to tame the cables and make sure they stay out of the propeller area at all times.
Connect the receiver using the male-to-male servo cables. You will want to connect the four basic functions (Aileron, Elevator, Rudder, Throttle) as well as an extra channel (AUX) for switching the autolevel function. In the end, you will have something like this:
The flight controller installed on the frame, with the receiver wiring going to the 2.4GHz receiver. If you don’t know which channel on the receiver is used for which function, check your transmitter for a channel output monitor. Note that your transmitter should be set for a new airplane model, NOT a helicopter model.
Mount the receiver on your frame, we chose the front end of the bottom plate for this. The 2.4GHz antennas need to be secured as well so they don’t get cut by the propellers. Again, you do not need to install the propellers just yet. That’s for Part 3 where we’ll check the motor direction and set up the KK2 board.
When securing a coaxial 2.4GHz antenna cable, make sure you put some protective tape or tubing over the antenna wire before tying it to the frame to avoid damage.
Voila! Your quadcopter is almost ready. In Part 3 we’ll take a look at how to set up the flight controller, checking the motor directions, and your first test flights!
The finished quadcopter with 1800mAh 3S battery.
Question on this build. I ordered the F330 frame, D2822/17 motors, and blueseries 20A ESCs from HK. Did you use the prop adapters that came with the motor or some other kind? I’m new to quads and I’m trying to figure out how all this works. Seems the motor shafts are pretty long and using the stock motor parts, the props sit quite high.
Yes the motors come with fitting prop adapters. There’s no need to order extra. If you order a different motor brand, then you may have to order those separately.
The props don’t sit very high. In fact the prop adapter itself contributes to most of the height.
Looking at your photo of the motor, your bottom prop adapter collar appear to cover the entire shaft of the motor. When I mount the adapter that came with my Turnigy D2822/17 motors, I still have ~ 1cm of exposed shaft. Did you cut down the shaft or do any other modification to your motors? Forgive me as I’m a newbie, seems that from what I’ve read up, the props should sit as low as possible to reduce vibration and lower the risk of bending the shafts.
Is there a reason for using the 330 frame instead of the 450? Would all of the parts still work with the 450 or would the extra weight throw things off?
Well this is meant for the smaller frame. It will work with the larger frame but won’t have as much power. You might want to use slightly larger motors and/or different props.
Great article! I used your recommended motors and props and the KK2 board. Substituted Afro 30A ESC’s and built my own wooden H-frame. My frame works out to 465-size so I can mount 8,9,or 10″ props. I love the 7″ 3-blade props; they are tough. I haven’t tried any flips yet but getting some nice video. Thanks!
Thanks for the kind feedback!
And yeah, the tri-blade props are awesome because they provide a good amount of lift while reducing the usual problems when descending vertically. Large props produce such an amount of turbulent air that they tend to make the craft really unstable. I’m definitely trying to use as small props as possible, going as large as needed to have a decent amount of efficiency and flight time.
What kind of radio transmiter do you recomend and it has to be cheap.
What kind of remote transmitter and receiver are you using?
Hi, I’ve gone through your 3-part article and couldn’t find where you mention battery or how to wire it. I’m a newbie, so it’d be great if you mention that too.
Still, very comprehensible tute. Tks
Hi. after a look at the build im still confused on what battery for the quad to get, im going to go with the orange rx t-six transmitter.
also will this build be able to lift a gopro?
Thanks
I too am confused about powering the fc and receiver. I see the input voltage range on the fc is between 4 and 6 volts. Where does the 5v supply come from? A second battery maybe?
Prithvi, I found out that esc he is using has a bec built into it. It puts out 5v on the red wire of the 3 wire servo cable that goes into the fc. That’s how they are powering it. I was told you should only use one of the escs bec output. So you should disconnect the red wire on three of the servo cable from the escs to the fc.
Hi ,
I suggest found this build by chance while I was surfing the web.
This is a cool FC KK2.1 at hobbyking.
Will I be able to replace this FC with the Naze32 FC in the Aerial freak Hyper 400.
Can anybody comment?
Thanks
Hi, great tutorial, I’m following it as my first quad build.
Quick question – I see you’ve updated the choice of prop, but it looks like 3 blade 7×4.5’s are kind of not easy to buy (at least hobbyking is sold out at the moment), would 2 balde 7×4.5s be able to do the job?
Thanks!