Bow-drill fire sets are a primitive technology using simple materials. Each set consists of a top piece, fire board, spindle and wooden bow. With a simple bow-drill set and a bit of strength and perseverance, you can make a fire anywhere at any time without matches or a lighter. The set can be taken on camping trips or simply used nearer to home to impress family and friends.
Understand the anatomy of a bow-drill fire set. The bow-drill set uses a top piece that is made of wood or rock, a bottom fire board, a spindle and a bow strung with cord. To make a fire, a person places the fire board on the ground, places the pencil-shaped spindle in a notch on the fire board and holds it in place at the top end with a hand-held top piece. By wrapping the bow's cord around the spindle and drawing the bow back and forth, friction is created between the fire board and spindle. As friction increases, so does heat, and a coal is created from the fire board material.
Make your top piece. Choose a piece of hard wood or a rock that fits nicely into your hand. If you are using wood to make the top piece, simply dig a small notch into the center of the wood. This notch will keep the spindle in place during the first uses of the fire set. If you are using a rock for your top piece, find a rock that is soft enough to be carved but not so soft that it will break when stress is applied. Using a file or another hard rock, carve out a small, half-spherical impression in the rock. It should be at least one half inch deep. The advantage of using a top rock as opposed to a top piece made out of wood is that the rock will stand up to the friction of the spinning spindle and will last longer. A wood top piece will need to be replaced fairly often.
Choose wood for your fire board. The bottom piece of the fire set, which will be used to produce a coal, should be made out of a wood that is soft enough to give in to the friction of the spindle. Some popular wood choices are juniper, aspen, poplar, spruce, balsam fir, and white cedar. Fire boards can also be made out of yucca. Wood choices will vary by area, so experiment for best results.
Make a fire board. For a bow-drill fire set, a fire board should be at least six inches long. There is no maximum length, but consider the ease of transport and use when determining length. For maximum efficiency, the board should be no wider than three or four inches wide and one to two inches thick. Cut a piece of wood into your desired size, and use a carving knife to flatten both sides. Make a notch in the wood about an inch from the edge; this notch will hold your spindle in place before it can burn its own hole.
Carve a spindle. A spindle can be made out of the same wood as your fire board, or you can experiment with different types of wood to test results. Choose a piece of wood between six inches and a foot long. Carve it until it is in the shape of a dowel, just under an inch thick. Sharpen both ends of the spindle to a point so that they fit in the notches on your fire board and top piece.
Make your bow. Find a piece of naturally curved wood about the length of your arm. Wood choice is not particularly important, but the bow should be strong enough to stand up to stress. Carve a notch in each end of the bow that is wide enough to hold your cord. Tie a loop in the end of your cord and slip it over one notch. Run the other end of the cord through the opposite notch and tie off. The cord should be just loose enough to wind around the spindle but should not slip off.