How to build a quadcopter?

Building a quadcopter at home is not as hard as you’d think. However it takes a lot of time and effort, soldering skills, and patience, patience,patience.

Building your quadcopter is not something you have to do: there are a lot of high quality quadcopters on the market today, and you can easily buy one that will suit your needs, skill level, and budget. Building is a great option if you love putting things together, and you will learn a lot doing it all yourself.

The quadcopter’s parts need to be in balance

, so if it’s your first build, the best is to go with a proven design. This will save you lot of hassle, as the motors, ESCs, batteries and propellers will all be properly matched together. If you fail to match these items, your quadcopter will likely have lower than expected performance, or could totally fail too.
For example a too large motor without the proper battery and ESC will weigh just too much to fly well, and will likely overload your ESC.
On the other hand, and undersized motor will not have enough power to lift your quadcopter, and will likely overheat too. If you’d still like to go with your own part list, eCalc.ch has very detailed quadcopter calculator which can help a lot.

The quadcopter parts list

The ZMR250 is a proven air frame, a lot of kits use this one. It’s the easiest to order one such kit online, for example this one from Amazon. The upside is that you will not have to go through selecting all the right parts:

  • The ZMR250 carbon frame kit,
  • 4x MT2204 2300KV Brushless motors,
  • 4x 12A SimonK ESCs (more info on these ESCs here),
  • 4x 5030 (clockwise) 2-blade Propellers (2 spare),
  • 4x 5030 (counter-clockwise) 2-blade Propellers (2 spare),
  • CC3D Flight Controller in protecting case
  • and the power distribution board.

Still missing and you will surely need:

  • An appropriately sized battery, something around 1300-1600 mAh, 3S (=three LiPo cells in series), fo rexample this one.
  • a 2.4 Ghz receiver and transmitter, for example this combo from Flysky,
  • 4xAA batteries for the transmitter,
  • soldering iron and solder,
  • and finally a balancing charger for the Lipo battery, for example a SKYRC iMAX charger.
Let’s build our DIY quadcopter!

The ZMR250 frame parts laid out.
The motor screws should not be too large.

The first step is to mount the motors on the arms. To do this simply screw the the bottom of the motors onto the arms. The arms are symmetric, so you can’t go wrong with this step. Take care to align the wires from the motor with the arms, so they are protected in case of a crash. To achieve a good fit, tighten the screws only once they are all in. The screws should not be too long, as that will ruin the motor’s wiring.

Motor – ESC detail.
The next step is to connect the motors and the ESCs

For the best connection you may want to solder the motor’s wires onto the ESCs. It’s a good idea to solder them such that they have the best chance to turn in the right direction. To achieve this, solder two motors with the wires straight to the ESC, and two motors with crossed wires. Make sure the wires are not too short, or you’ll have a hard time reaching the power distribution board. Once finished, cover the ESCs with heat shrink tube or simple tape for insulation – shorts can cause fire and you could lose your quadcopter to it. It’s best to make sure they can’t happen.
Choose the simple solution here, and fix the ESCs onto the arms with additional tape.

After the ESCs are in place, screw the arms between the baseplates.

The arms should line up to give the quadcopter the “H” outline. Note the motor’s rotating directions when placing the arms with the quad looking away from you – they should be CW (straight wiring) front left – CCW (crossed wiring) front right – CW (straight wiring)rear right – CCW(crossed wiring) rear left.

By this time the quadcopter should be shaping up pretty well, so it’s time to move onto the other electronics.

The arms mounted between the two baseplates. PDB is on the top.
This is how you wire up the PDB. The CC3D flight controller accepts anything between 5-15 volts.
Soldering the ESCs onto the power distribution board is straightforward.

Just make sure you do not mix up the poles, solder the black wires to the negative pads, and the red wires to the positive pads. Once done you can move on to soldering the battery connector, again red to the positive and black to the negative pads. Once ready you can screw the standoffs onto the baseplate, then the power distribution board onto the standoffs. Use another pair of standoffs to fix the flight controller onto the power distribution board.
The flight controller will get it’s power from one of the ESCs via the wires between the ESC and the flight controller, so there’s nothing to solder here.
The receiver will get it’s power from the triple-wire connector from the flight controller – again it’s something you do not have to care about.

CC3D flight controller – FSiA6receiver wiring.
Connecting the flight controller and the receiver.

After connecting the power wires, you can start connecting the data wires too. First up is the connection between the flight controller and the receiver: plug the connector into the flight controller, next plug the individual plugs into the receiver. White is the throttle, blue is the roll,yellow is the pitch, and brown is the flight mode.

The CC3D’s ports.

Next connect the ESCs to the flight controller.
With the quad looking away from you, the front left ESC is #1 (CW), front right#2(CCW),rear right #3(CW), and finally rear left #4(CCW). When plugging in the ESCs,the yellow wire (the signal) should connect to the innermost pin, and the brown wire to the outermost pin. If your flight controller is ready use more spacers and screw it onto the top of the PDB.

Having put almost everything together it’s time for a quick test.

Charge the battery and connect it to the quadcopter, and power up your transmitter. Using a smoke protector is a great idea – it can save you a lot of hassle. You will have to bind the transmitter and the receiver – just see this short video, it’s less than 2 minutes. After binding is complete you should check that the quadcopter works as expected. Do not put the props on yet -they could cause trouble.

  • if you throttle up, all the motors should start spinning
  • they all spin in the appropriate direction
  • if you push the “tilt forward” stick forward (right stick in mode 2,left stick in mode 1) the rear motors should start spinning faster.
  • if you push the yaw stick left (left stick), the CW direction motors should speed up (front left and rear right) while the CCW direction motors should slow down (front right and rear left)

If there’s anything amiss you will have to debug it with clean flight. There are quite a few guides on it, this one on youtube is really good; if you prefer reading check this guide.

Everything looks good? It’s time to install the props!

Clockwise prop cross section.
To install the props on your quadcopter

When installing the props make sure you put the clockwise props on the clockwise motors, and the counter-clockwise props on the counter-clockwise motors. To identify the propellers, look at them with the blade pointing towards you. The cross section of the counter-clockwise props is the mirror image of the clockwise props. Tighten the props with the nuts.

The large standoff with the screw visible.
Getting ready for the first flight

To get ready for the first flight, use the large screws with the long metal standoffs to install the top plate. Finally mount the battery on the top – velcro and zip ties work wonders here 🙂

The top plate on the standoffs.
Now your quadcopter is ready for flying.

Quadcopters are dangerous, so before trying your quadcopter out make sure that

  • your are out in the open, away from anything you could hurt – people,cars, animals, windows
  • increase the throttle only gradually, never push it up to the maximum
  • take your time to expand the flight envelope
  • if in doubt slowly throttle down
  • the quadcopter propellers can cause serious injury so do not flyclose to humans or animals (I actually cut my mattress with a spinning prop.)
  • make sure it’s actually legal to fly in your area.
  • if you are in the US and your quad weighs more than 0.55 pounds (250grams), you’ll have to register it with the FAA. Your ZMR250 will probably weigh around the double.
Happy flying!
3-2-1 and we have a liftoff!

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