Cabinetmaker's Sector

The sector is a physical instrument made to aid in various proportional and geometric layout tasks. Produced from the sixteenth to nineteenth centuries, this tool was used by gunners, navigators, surveyors and anyone performing physical calculations with dividers, compasses, pen and paper.

This is a renewed version of the tool, scaled and revived for use by modern woodworkers. It has three scales to work with- the "Line of Lines," "Line of Circles" and "Line of Polygons." The "Line of Lines" (in black on the face of the sector) is used to divide and multiply lengths (though with that capability, it can be used to perform complex geometric constructions). The "Line of Circles" is constructed to calculate the radius, diameter or circumference, given one. Lastly, the "Line of Polygons" is used to layout the vertices of a four to twelve sided polygon on a circle, given the radius of that circle.

This is the culmination of many months of research and development- I will be posting a full length description of the tool, my own personal research and my collaborative work with Jim Tolpin and George Walker on the Sector's tool page. And for even more information regarding the use of the sector, please visit where you can find some amazing articles, pamphlets and posts about the use of the sector. 

Each sector is labeled with edition and number, X-XX, so 101 is edition 1, sector 1, 214 is edition 2, sector 14.

Below, you can find a basic introduction and set of tutorials on how to use the tool!