Flying a Quadcopter with the Wii Remote and Arduino (1): Materials

【Warning】
I strongly advise against flying this in any area where people or buildings are nearby.
The Wii Remote's sensors were not designed for RC use.
Loss of control, flyaways, and crashes are real risks.
Take full safety precautions before attempting anything like this.

Quadcopters have been all over the news lately. I built one controlled by a Wii Remote.

My flying is rough and the tuning needs work, but here's what it looks like:



I checked that the area was clear before starting, but a crowd gathered while I was flying.
I had implemented an emergency drop command and a forced-landing mode (described later), but even so — the risk of a runaway made for a somewhat nerve-wracking situation.

Destroying the frame is one thing; injuring someone is entirely another.
Please be careful. Actually — don't replicate this.
(I know, if I say that I shouldn't be writing it up — but this is meant as a technical explanation…)

To build a quadcopter from scratch, you need at minimum:

• Quadcopter airframe (frame / electronics / drive system)
• Propellers
• Battery
• Flight controller
• Receiver
• Transmitter
• Miscellaneous extras

Let me go through each.

Airframe (Frame / Electronics / Drive System)

"Airframe" covers a lot of individual parts. The main ones are:

• Frame
• Electronic speed controllers (ESCs)
• Brushless motors

Matching frame size, weight, and motor output is fiddly — sourcing each part separately takes a while.

Frame

Check on Amazon
I bought a NEEWER HJ450 frame from Amazon.

In hindsight, a smaller motor-to-motor distance (i.e. a smaller frame) would be easier to manage.
I needed some extra lift for the custom receiver, so a mid-size frame worked, but you don't need to go this large.

The bigger the frame, the heavier the build — and the more dangerous. Smaller is better.

Electronic Speed Controllers (ESCs)

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ESCs (also called BECs) translate the flight controller's signals into motor power.
I used four 20 A units. They look like mystery objects and are surprisingly expensive.

Brushless Motors

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Not just any motor — the mini-4WD DC type won't cut it here.
Quadcopters use brushless motors for the precise speed control they need.

I used four A2208 KV1400 motors. Which motor you need depends on the frame weight and other factors — I'll be honest, I didn't fully understand the spec sheet.

Propeller adapters are included. They are extremely easy to lose, and almost impossible to replace — be warned.

Other Items

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ESCs and motors are expensive — a lead that breaks mid-flight is heartbreaking. Using banana plugs for all electrical connections makes them detachable, which is a real quality-of-life improvement.

Cable ties from a 100-yen shop also come in very handy.

…That said, frame selection is tricky, and for the airframe specifically, buying a pre-matched assembly kit from a shop like RC-E-Tech is probably the safer choice.

Just covering the airframe has gotten long — more in the next part.