It's fairly simple, and a great one to do with kids.
Date made: June 2013
Approx Cost: £0 (recycled materials)
Approx Time: 0.5 to 1hr
Step 1: What You Need
*2no bottles (I used one 500ml for the propeller, and one 600ml for the body, but you could experiment with different sizes and shapes)
*3no elastic bands
*2no paper clips
*1no piece of wood about 150mm long (maybe an old broken ruler? I ended up using 2 plant markers)
Tools you will need:
*knife or scissors (I used a combination of both)
*drill or some sort of punch (I used a 2mm drill bit)
*long piece of hooked wire (coat hanger?)
*random tools for bending the body paper clip (you'll see!)
Step 2: Propeller
Cut holes in one side of each ridge (the same side on each). This will give you a propeller shape as per the photos.
Then drill a hole in the middle of the propeller and the other bottles cap, just big enough for a paper clip. Drill an offset hole in the propeller to lock off the paper clip too.
Next bend the paper clip and feed it through the cap and the propellor as shown in the photos. I ended up using a bead between the propeller and the cap to reduce the friction.