PROJECTS: Remaking History
This geometric truth means you can multiply,
divide, find ratios, scale up, scale down, and
so on, just by building or measuring similar
triangles. And that’s how the sector works; it’s
basically just a quick and easy way to build and
scale similar triangles.
Making a sector is an easy and inexpensive
project and something that parents and children
can make together and have fun using even
without a specific goal in mind. But don’t let its
relative simplicity fool you; the sector is useful to
woodworkers, artists, metal workers, and others
in a bunch of different ways.
So, let’s get started. First, we’ll fabricate the
frame of the sector instrument. Then we’ll make
the all-important scales that are written, printed,
or inscribed on the frame pieces. Finally, we’ll
use the sector to do different types of important
mathematical jobs.
HOW TO MAKE THE SECTOR
1. Use your saw to cut out the two L-shaped
frame pieces as shown in Figure
C
. You can use
thin plywood, solid wood, plastic, or any light,
non-flexible sheet stock that you can cut into the
shape shown. I used ⁄"-thick HDPE plastic and it
worked great.
2. Drill a ⁄" diameter hole in each piece at the
spot indicated in Figure C.
3. Insert a #6, ½"-long bolt with two washers into
the hole and gently tighten with a wing nut.
HOW TO MARK THE SECTOR SCALES
The sectors made by the great European
instrument makers of the 17th, 18th, and 19th
centuries had a lot of different numerical scales
etched into them. Each scale was used to
11"
11"
Use ⁄" drill bit to make clearance hole for #6×⁄" long bolt
2"
2"
1"
1"
2"
⁄"
4"
Sector leg 1
Sector leg 2
2"
⁄"
Wikipedia Commons
4"
96 makercampus.com
C
D
M77_094-99_RemHist_F1.indd 96M77_094-99_RemHist_F1.indd 96 4/12/21 12:11 PM4/12/21 12:11 PM
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.