There are 4 parts to a bow drill set–the spindle, hearth board, hand socket, and the bow itself.
In this demonstration I use two different spindles. One, I made from yucca and the other, I made of cedar. Although neither of these woods are common here in north Georgia, I scored by finding the yucca plant on the side of the road as I was taking a group of kids on a wild edibles walk. The cedar was given to me by a fellow outdoorsman, Mr. Mitch Camp who who also taught me how to white water kayak. Both of these woods have little sap and are very soft wood which makes them ideal choices for spindles.
The tip of the spindle that will make contact with the hearth board should be almost flat with a small point for maximum friction.
On the other end of the spindle it should be a bit more pointed to reduce friction between it and the hand socket.
This spindle is a bit too flat for most hand sockets, but my hand socket is slightly different from most. If the friction is minimal in the hand socket then it is maximum in the hearth board, so I hammered a dime into my hand socket just for a small advantage.
Your hearth board should be made of very soft wood also; I used cedar. After carving a small indentation you should work on your notch which is very important.It should go about three-fifths of the way through your indentation and get wider as it goes down.
Last but not least, your bow should have just enough slack to twist around the spindle once. It should be about 30 inches long, and be comfortable to hold.
When you have all your components ready, set them up like in the following way. First, twist the rope around the spindle and place the flat end of the spindle on the indentation of the hearth board. Then, put the pointy end in your hand socket. Apply downward pressure to hand socket and move the bow back and forth which will spin the spindle. Slowly add more pressure and speed. When you see smoke, give it all you got, and pray for an ember. When your muscles are dead, take away the spindle and see if the sawdust created by the friction is still smoking; if it is then you have and ember.
You can’t see the smoke in this picture, but it was there. When you see this, fan the ember with a leaf gently until you see a red glow. Then place the ember in your tinder bundle and breathe it to life.
Because of a burn ban in my area I could not light a tinder bundle, but that is the easy part. As it was, I got the coal in my bedroom, and my mom busted me in the process. I explain how to make a tinder bundle in my post How to Light Fire With a Faro Rod.