Originally posted on MAKE:
A pump drill is an ancient tool traditionally used to generate friction heat for starting fires, as well as for boring holes. The principle of a pump drill’s operation is easy to grasp, but hard to explain. It’s similar to the button spinner or whirligig, in which rotational momentum is built and maintained by repeated twisting and untwisting of a cord.
I first got interested in pump drills after reading a 1993 article by Anthony Follari, originally published in the Bulletin of Primitive Technology #6, about the design, construction, tuning, and operation of fieldcraft pump drills for fire-making and hole-boring. That article, and many other fascinating pieces from the Society of Primitive Technology, has been republished in an outstanding compilation called Primitive Technology: A Book of Earth Skills. After reading it, I got interested in the idea of a “modern” pump drill, operating on the same principle as…
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