From top to bottom: The first sector I made to demonstrate whole-number divisions; my three-scale paper version; a solid wood and brass sector by burn-Heart
I first stumbled on the sector as a layout tool through an article by Tom Casper in Woodwork magazine that appeared in the late 90’s. My curiosity engaged, I went through all the woodworking books in my considerable collection and couldn’t find a single reference. It turned out that the sector is essentially extinct. But as Tom pointed out, it was–and is–incredibly useful. The sector could effortlessly divide–with no measuring and therefore no math (fractional, decimal or otherwise involved)–a certain space up into whole number segments. When I presented the sector in my book “Measure Twice, Cut Once”, I showed how to locate drawer pulls two-fifths of the way in from either end of a drawer face.
I left it at that until just a few years ago when, on the recommendation of Joe Youcha (www.buildingtoteach.com), I got a copy of The Victorian Cabinetmaker’s Assistant published in the mid 1800’s. Here I learned that not only could the “Line of Lines” provide multiplication and division solutions along line lengths but it could also lay out (or find) whole number proportional relationships.
At this point having become rather obsessed with this tool, I sought out even earlier manuscripts from the 1700’s that described further workings of the sector. When I finally understood that the geometry of the sector allowed it to solve for unknowns among all sorts of ratios, I added another scale to a paper version that could provide solutions for the diameter, radius or circumference of a circle (i.e. the “Line of Circles”). The realization that the geometric truth underlying the six-sided figure (the hexagon) could produce another scale to provide the facet length of other polygons was exciting enough to keep me up half the night–and in the morning I added the “Line of Polygons” to the paper sector.
You can download a free template of this sector over in the shop section of this website–and you can also download a not-as-free, forty-page pamphlet that tells you how to use it. But you still can’t buy a “real” sector at Home Depot or anywhere else since they stopped making them (as far as I can tell) more than 100 years ago. Until now!
Due to the enormous efforts and talents of Brendan Gaffney of www.burn-heart.com), we now have a limited number of his solid maple-and-brass hinged sectors in stock. Read more about them over on our shop page where there is also a link to a video on working with it. This batch is the last of his first run so this is your last chance to get your hands on a first edition!
7 thoughts on “Sector Madness!”
For the history, the beautiful instrument that Brendan Gaffney has constructed, and for the concept of making by proportion and less by strict measurement.
I’m guessing he also made the hinge mechanism – which by itself is proportional from side to side. two thin blades on one side and one thick blade on the other with the thin ones being about the same total thickness as the other one. Cool design!
When do you anticipate having additional sectors available for sale?
Brendan Burnheart Gafney is the creator of these wonderful wooden sectors. HE recently took a position with Popular Woodworking magazine as editor. That job change and move from Maine to Ohio has put his toolmaking on hold. Right now we do not have a date when he will resume production. Keep posted on the blog and we will update when they become available.
Will there be another run of this beautiful tool.
I see from the dates no update has happened. I have Basswood, downloaded the template, and own sharp cutting tools, but it sure would be cool to have that hinge. Any possibility that is actually commercially available? I could possible adapt and use something like a knife hinge, but it won’t turn out as nice.
I don’t see Brendan making hardware available again. I suggest looking at possible substitutions like the knife hinges you mention.
I made a spread sheet to calculate where to put marks for the three scales.
Looking for a suitable hinge design.