I like stuff that flies and have about 10 RC airplane wrecks to prove it. :-) So when i think of things to build i often do something that flies... or at least tries to.
This project was inspired by the old wooden toy that is basically just a propeller on a stick. You spin the stick between your palms and it flies.... do it the wrong way and it attacks your hand. I thought that it must be simple to make a launcher that spins a prop really quickly and after all sorts of really complicated ideas the simplest as always was the best.
The project is made of simple steel tubing with a long bolt going through the middle, a couple of discarded skate bearings and nuts. A string wound around the bolt spins it as it is pulled. The spinning motion is transferred to a propeller and WHOOSH off it goes. It even makes that sound! seriously!
here's a youtube link of the prop in action...
http://www.youtube.com/watch?v=iy-BiMZP3Fc ( just copy and paste into your browser)
Anyone can make it with very simple tools. During the steps I will suggest both simple and more complicated methods so that you can challenge the beginners and advanced students in your class.
Turns out that the project has TONS of teachables in it. Here are some learning objectives...
History.... The students will research and apply the information gained about historical approaches to flight to investigate propellers and helicopter blade design
Design... After research has been compiled the kids will use that information to creatively design three propellers.
Geometry... Students will learn how to use a compass to subdivide a circle into even parts.
Using the Scientific Method... Students will evaluate the performance of the propellers after first writing a hypothesis, testing the props and drawing conclusions based on their observations
Pattern-making... The students will develop a pattern than transfer the pattern to metal.
Metalwork... Basic metalworking skills will be learned and applied to produce the parts required to build the project. Simple skills will involve a drill press, hacksaw and aviation snips as well as files and sandpaper. More advanced skills could be applied to increase precision such as the use of a lathe, MIG or oxyacetylene torch. (the examples i use are all with simple tools)
-ball peen hammer
-1 1/4" x .120 steel tube. About 6" long. You can use any pipe at all... any material as long as the ID is the same as the OD of the skateboard bearings.
-1/16" welding rod
-5/16" aluminum rod
-aluminum tube... 5/16" ID... about 1/8" wall thickness. Steel is usable, too...
-0.50 aluminum... Very thin aluminum... 6" square.
-5/16" 6" carriage bolt
-5/16" washers (3) and nuts (3)
-JB Weld or Epoxy
-Compass, Ruler, pencil, sharpie
-Drill press or Hand drill
-1/16, 1/8", 9/32" drill bits
-assorted smooth files
-Bench vice (or some kind of clamp...)
Or you can just follow the steps and build a cool flying thingie. Your choice... :-)
Submitted by HD Stafford Middle School for the Instructables Sponsorship Program