A teepee, or tipi, is a conical shelter usually made out of canvas and supported by lodgepoles. The basic design for the teepee is a half-circle with cutouts for the entrance, flaps to hold the teepee together and smokeflaps at the top.
Size and Geometry
A simple teepee is made from a half circle of fabric. Choose the size you want to make. The radius of the circle is equal to the diameter of the teepee when it is set up. If you want a child's teepee with a diameter of six feet, use a half circle of fabric with a radius of six feet. Leave an extra 1 inch to 1-1/2 inch border so you can hem the fabric. Practice on a scaled-down version made out of a sheet of paper.
Choose the Fabric
Typical manufactured teepees use cotton army duck canvas, 13 or 15 oz. per yard weight for mild weather teepees. Use heavier canvas for colder weather, up to about 20 oz. per yard. Some canvas comes with a waterproof finish. Teepees made out of buffalo hide were traditional, but went the way of the buffalo in the 1800s and teepees have been made almost exclusively out of canvas ever since. Make sure the fabric you choose is not too heavy for your sewing machine. If need be, you can have your final teepee assembled by a sailmaker.
Draw the Half Circle
You will probably have to sew several pieces of fabric together to get a piece large enough for your teepee. Lay out the fabric flat and smooth on the floor. Find the center of one of the long edges--call this the top edge. Anchor a string at the center and run the string to the outside corner of the top edge (either corner). Tie a pencil or marker with the string so the point is touching the outside corner. Now draw the semicircle by moving the pencil in an arc from the first outside edge all around the fabric to the other outside edge.
Opening at the Top and the Door
Use the same string and pencil to draw a half circle opening at the top and an opening for the door. The door will be cut from the top edge, a half circle on either side that will meet when the teepee is assembled. Cut the teepee out of the fabric. There are also door designs specific to different types of teepees.
Sewing the Teepee
Hem the fabric so it doesn't unravel. To make it easier to sew the curved portions of the teepee, let the sides of the fabric drape over either side of the sewing surface--the curve will appear as a straighter line. A rope is sewn inside the curved portion of authentic teepees. You need to add flaps on one side above and below the door opening. These are used to join the teepee together when you assemble it. You can also add smoke flaps for an authentic teepee. You can make the teepee out of a single piece of fabric--choose the style of teepee you want and find the exact pattern.
Joining the Flaps
The flaps that hold the teepee together above and below the door are traditionally held together through a pair of holes with a stick threaded through them. Make matching buttonholes in the top flap and the bottom where the flap will rest. Space these vertically about every six inches. You can also use buttons or Velcro for smaller teepees.