Student handout

Prehistoric Pump Drills

Archaeologists think that the pump drill may have been used by Native Americans to start fires. The pump drill produces heat from friction as it spins. This could have been used to ignite tinder or kindling.

The pump drill also does a very good job of drilling, both in wood and stone! Poverty Point people were noted for their stone tools, especially the small microliths used for drilling, punching, and other work. The pump drill could have been used to make holes in beads, pendants, plummets, and bannerstones. Broken bowls made from steatite were mended by drilling holes in the pieces and then tying them back together.

Microlith


Plummet

Bannerstone

Owl Bead
If you attach a one-inch-long microlith-like stone point to the end of a pump drill, you can drill a nice hole in very little time. If you want to drill a hole in stone, use a piece of river cane for a drill bit. Sprinkle some sand where you are drilling to serve as grit between the stone and the drill.

Steatite Bowl
Clarence H. Webb (1982)
courtesy of LSU Dept. of Geography and Anthropology

To work the drill, twirl the horizontal hand piece in one direction to twist up the string. This should cause the hand piece to be pulled up toward the top of the drill. Put your hands on either end of the horizontal hand piece and gently push down. This will start the pump drill spinning! When it has spun all the way in one direction, it will reverse and spin in the opposite direction. As long as you gently move your hands up and down, the pump drill will continue to drill.

Be careful not to push down too hard on the hand piece which operates the drill. A gentle up and down motion is sufficient. After the drill's momentum is established, it will almost operate on its own. If you try to push down really hard or try to make the drill spin very fast, the string holding things together may break. Pieces of drill flying through the air create a dangerous situation! Pump drills are fun to make and to use! Remember to be careful with your prehistoric pump drill and to always drill on scrap wood. Wear safety goggles to protect your eyes!

Materials:
16 inch length of 1 inch diameter dowel for the hand piece
24 inch length of 5/8 inch diameter
dowel for the upright piece
12 inch length of 5/8 inch diameter dowel for the crosspiece
Heavy nylon string
Dental floss
Two rocks that are the same weight and size or several large heavy washers with holes in the middle
Microlith stone point (get from rock shop)
Epoxy or wood glue
Electric drill
Safety goggles

Directions:

1. Drill a 3/4 inch round hole through the middle of the 16 inch hand piece as shown in the picture. The 24 inch upright piece will need to fit through the hole easily and be able to turn without sticking.

2. Drill a hole for the stone point in the bottom of the 24 inch upright piece. Insert the stone point into the hole and epoxy it into place.

3. Drill a horizontal hole through the top of the 24 inch upright piece so that a string can pass easily through it. Drill small holes through both sides of the 16 inch hand piece so the string will pass through both ends.

4. Put the 24 inch upright through the hole drilled in the 16 inch hand piece. Tie the string to one end of the 16 inch hand piece, run the string through the horizontal hole in the 24 inch upright and then tie it through the other hole in the 16 inch hand piece. The sideways hand piece should hang freely, a little more than halfway down the drill.

5. Find the middle of the 12 inch crosspiece. This will need to be attached at right angles to the upright piece. Carve out one side of the 12 inch crosspiece so that it that it will fit snugly against the upright.

6. Tie the crosspiece onto the upright piece so that it is about three inches below the hand piece and at right angles to the upright. Glue the two pieces of wood together with wood glue. Then tie dental floss or string in a cross pattern to make sure the joint stays in place. This also looks like the sinew the Indians would have used.

7. Make your weights on the crosspiece by securing a weight to each end of the dowel. You may use stones or an equal number of large washers on each side. These will provide weight to give the drill the momentum it needs to stay in motion. Be sure these are attached securely so that they don't fly off in the middle of drilling!

Just for Fun!

Try using the drill without the weights on the crosspiece! What happens? Why?