How To Build a Cardboard Quadcopter

Step Five – Attach The Motors

I put nylon mesh jackets on the motor lead wires. This helps keep them neat and tidy, and protects the leads from prop strikes and other mishaps.

As your motors probably didn’t come with the 3mm bullet connectors, you’ll want to solder them on now. I use a little piece of cardboard with holes punched in it to keep them stead while soldering. Drilling into a block of wood also works well too. Careful, if you put them in a metal vice it will make it very difficult to heat the connector and wire up.

Unlike most multi-rotor designs, the thing this one lacks is screws. Except for the motor mounts, pretty much no way out of that. This is important because screws, bolts and standoffs can add a lot to the cost of a frame. There are a lot of different ways to construct the motor mounts, but what’s most important is that there be two flat tabs sticking out from under the motor that are about 0.5″ or 12mm wide which we can use to tape the motor onto the arm. I can hear you now: “tape?” If you use the right tape, it works amazingly well.

The first step is to use the hole chamfer to but a bevel in the the motor screw holes one one side. The next step is also important: on the other side, taper the center hole slightly. This is important as otherwise the shaft snap collar on the motor will brush against the motor mount and you’ll see a lot of yaw drift in flight.

Attach the motor mounts to the underside of the motors, and put a little Lock-Tight in the screw holes. Without it, they’re pretty much guaranteed to vibrate out in flight, sending you on a quick trip to the hardware store for a somewhat rare 3mm machine screw.

Place them at the end of each arm and tape them down tight. If they’re taped on loosely the extra play will get larger over time from vibration. If they’re tight they’ll stay put for a very long time.