http://www.ehow.com/how_4699048_homemade-rc-helicopters.html
I learned alot reading this link, I got a tip to making the main body. The material that they used to make the main body of the helicopter would make you feel surprise. It is the circuit board ( after removing the copper layer ) that purchased from electronic shops. It is made of a kind of fiber which gives abnormal strength to it.
The circuit board is cut to the rectangular shape as above( 98mm*12mm). As you can see, there is a hole on it which is used to house the main shaft holding tube as below: The main shaft holding tube is made from a white plastic tube (5.4mm*6.8mm) and two bearing (3*6) are installed at both ends of the tube. Of course, the ending of the tube are first enlarged in order to house the bearing firmly. Up to now, the basic structure of the helicopter is completed. The next step is to install the gear as well as the motor. You can take a look at the specification first. The gear I used is from Tamiya gear set that I bought long long time ago. I drill some hole on the gear in order to make it lighter and have a better
This is a different way to build a mini helicopter. The steps are making a bending jig.
Using pliers, bend the nails over about 30 degrees from vertical (60 degrees from the horizontal wood). Take care that whichever way you are holding the jig, the nearer row of nails always slant to the right and the far row always slants to the left.
Marking, drilling and bending the tongue depressors. The tongue depressors need to soak in hot water so they stay twisted. If you can heat the water to almost boiling, the tongue depressors only have to stay in a minute or two. If you are using hot water from a tap you should let the tongue depressors soak for 15 minutes or so. Step 3 is c
utting out, forming and taping the airfoils. Use a sharp corner of a table or a straightedge to fold exactly on the dashed line.
Curving the cardboard is difficult to describe but you will know as soon as you get it. It is not the previous step of creasing on the dashed line, but rather making the whole piece of cardboard curve. In the illustration the right hand firmly grabs one of the "up/down" ends and pulls it down and to the right around a sharp corner. The cardboard should bend as it goes around the corner. The left hand pushes down hard on the cardboard, making it resist the pulling. The operation is somewhat similar to the way people curl ribbons. Start the sharp corner at the middle where the dashed line is and pull to the edge. Flip it around 180 degrees and curve the other half. Take off the pattern and the tape holding the pattern. When you hold the two edges together as shown, you can see how the curves make it form something close to a symmetrical airfoil. Cut off some electrical tape (red in this illustration) 3" or a little longer. Stick half the tape to one edge. Press the edges together and fold the other half over the other edge. Trim the ends if tape sticks out on the ends. This taped edge will be called the "trailing edge" from now on because it will be the back of the airfoil. The other edge is called the "leading edge."
. How to Make Homemade RC Helicopters. N.p., 07/23/2010. Web. 23 Jan 2012. <http://www.ehow.com/how_4699048_homemade-rc-helicopters.html>.
