Helicopters are complex machines. They require high quality parts that are strong, lightweight, and accurate. Those are terms typically not associated with parts made on home 3D printers.

But could they be?

We all know home machines are getting better, but could you actually print a working helicopter on a home 3D printer? The obvious place to start is the blades. They must be thin, light, smooth, and strong. If you can't print blades, you can't make a helicopter. So can you?

Well, spoiler alert: you can. But do they actually work? Or do they fly apart when they spin up, or generate too much turbulence to actually fly?
See for yourself:
http://www.youtube.com/watch?v=qXlUSWrVzys

Printed on my Ultimaker 3D printer, using Netfabb "Ultra" (0.08mm) profile, 100% infill, 100% speed, no raft. Takes about 26 minutes per blade.

The helicopter is the "JXD 340", or sometimes the "Drift King" because unlike most cheap helis, it can fly sideways. Its a pretty awesome toy for $30, and much better than most cheap helis I have seen. Personally, I recommend it. Have a link:
http://www.amazon.com/Indoor-Infrared-Control-Helicopter-Gyroscope/dp/B004OGBNJ8/
And no thats not an affiliate link, I just think those toys are sweet.

SAFETY NOTE: I recommend PLA because it sticks well and works well with small layer heights. HOWEVER, PLA is brittle, and when these blades break, they tend to shear off and send a sharp piece flying. The pieces are light and it may not be an issue, but you have been warned. If you're about to crash, cut throttle power so the blades stop spinning and the amount of energy put into them is reduced. They've survived plenty of nicks on things, but if you crash under power they will break. Ultimately though, I am not responsible. Print at your own risk.