Pull the string and watch your Whirligig fly across the room. Print 2 handles and pass back and forth with a friend. Tilt at 45 degrees in the direction you want it to fly.
To launch, place the whirligig on the handle and wind the string. Be sure to wind clockwise when viewed from the top of the whirligig/handle.
Also comes with a stick so you can launch with your hands, if you prefer that method. Place the whirligig on the end of the stick and hold the stick between your hands with your hands flat. Quickly push your right hand forward. The whirligig will detatch from the stick and fly (you don't want the stick to stay in; the extra weight will cause it to not fly as far).
Stick launched version flies 20 ft (6 m).
When I first designed this, I did not think it would print, but it did and it flies well. Printers have trouble with 2 in bridges and 15 degree inclines in general, but the two together seem to work.
String launched version:
Requires 2 vitamins:
1. String about 3 ft (1 m) long. Tie a bowline knot with 1/4 inch (6 mm) diameter loop at one end. http://en.wikipedia.org/wiki/Bowline
2. Nail roughly 2 inches (5 cm) long with 0.093 inch (2.4 mm) diameter shaft. For best results, flatten 1/4 inch (6 mm) from point with hammer (refer to the attached image). I used a blow torch to heat the tip to red hot to ease flattening (Be careful. Use pliers to hold the nail. Don't burn yourself). Flat portion should be 0.050-0.060 thick (1.3-1.5 mm). Nail shaft diameter is not critical. You may need to scale the nail clip to match your nail diamter. The scale option on your host software will work fine for this since no other dimention on the clip really matters.
Assemble as follows:
Print whirligig, string handle, quick release, nail adapter, and nail clip (1 each). I used a 0.18 mm layer height.
1. Push the nail, flattened tip first, through the handle. The flattened tip should stick out the top of the handle.
2. Push the nail adapter on the flattened end of the nail. It should be a tight fit. If it is too loose or you opted to not flatten the end of the nail, use some glue. At this point the nail is trapped, the coupling prevents it from sliding out one way and the head keeps it from sliding out the other way.
3. Glue the quick release to the end of the nail adapter.
4. For ease of winding, snap the nail clip onto the nail between the two handle beams. This will probably need glue.
Start wrapping the string by putting the bowline loop over the nail clip and spin the nail.
Stick Launched Version
No vitamins required.
Assemble as follows:
1. Print whirligig, stick, and quick release.
2. Glue coupling to stick.
Parts print fine with ABS or PLA. I have found ABS to work better for the whirligig because the PLA is brittle and breaks more easily when it impacts a wall. It does not matter what material you use for the non-flying portion.