For a school assignment, we had to design an airplane. It had to either fly as far as possible, or as long as possible. I was assigned the latter. We couldn't use battery or motorised power. I used a windup-system.
Step 1: What Do You Need
*Balsa Wood: one beam (15x15x1000 mm) and one plank(3x10x1000 mm)
*Aluminum tube (outer diameter: 6mm, inner diameter: 5mm)
*wind-up system (recover this from a toy) I used Sparklz wind-up
*propeller. I used 8x3.8 ACP slow-fly prop
*adhesive foil. Chose your own colours, be creative!
Step 2: Wings
Scour the styrofoam so the profile looks like an airfoil (aerodynamic). In front view, there should be a bulge in the middle of the wings. This is where we will slide the hull (balsa beam) through. Cut out the hole (15x15mm) where the hull will fit.
Step 3: Tail
To make the tail we need the balsa plank. Cut off a piece of 30 centimeters. Round the edge of the plank so that the front of the plank is completely rounded, and the back is still in a right angle. Do this for both sides of the plank. Scour the whole thing so it is aerodynamic. Glue it perpendicular to the hull with woodglue. It should be placed at the very end of the hull.
Now cut out another piece, 20 centimeters this time. Round the edge of the plank lik you did before, but this time only do it for one side. It should look like a shark fin. Do the same thing for two planks of 15 centimeters.
Now glue these three planks together, the largest one in the middle, and the bottoms parallel. Scour everything until it is aerodynamic, and then glue it perpendicuarly in the middle of the other piece of the tail.
Step 4: Testing
It would be best to test the plane at this stage. You should adjust the wings until the plane balances nicely, this way it will fly better. If your plane diverges from its course, you will have to scour the styrofoam a bit more until you plane flies straight ahead.
Step 5: Adhesive Foil
Wrap the wings in adhesive foil. This wil benefit to the sturdyness of the wings, and it will look better too, so be creative!
Step 6: Wind-up System
Strip your wind-up toy of all the unnecessary stuff attached to it. You should have an axis and the wind-up system itself left. Attach the aluminum tube to the axis of the wind-up system. You choose the length of the tube, but beware; the longer it is the slower the propeller will spin.
Step 7: Assemble the Plane
Slide the wings onto the hull. Attach the wind-up system to the front of the plane. If you do this you will not be able to remove the wings anymore. The axis of the wind-up system should be parallel to the hull.
Step 8: Propeller
Slide the propeller over the aluminum tube, and wind up the system. Now you can test your plane!