# Square-Hole Drill in Three Dimensions

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One can combine the use of a Reuleaux triangle to make a square-hole drill with an Oldham coupling to make a drill that has one end following pure circular motion, while the other end has a cutting tool that follows an exact square. This idea appeared in a 1939 note in *Mechanical World*, with no author given, and was recently popularized in the book *How Round Is Your Circle?*; the authors made a working device along these lines. More details of the square-hole drill portion can be found in the Demonstration "Drilling a Square Hole".

Contributed by: Stan Wagon (Macalester College) (March 2011)

Open content licensed under CC BY-NC-SA

## Snapshots

## Details

Reference: J. Bryant and C. Sangwin, *How Round Is Your Circle?*, Princeton, NJ: Princeton University Press, 2007.

## Permanent Citation

"Square-Hole Drill in Three Dimensions"

http://demonstrations.wolfram.com/SquareHoleDrillInThreeDimensions/

Wolfram Demonstrations Project

Published: March 7 2011