Chrisaan Huygens and the
Pendulum Clock
groundwork for the physics of Isaac Newton;
and designed and built one of the first vacuum
pumps (see my article “Robert Boyle and the Air
Pump” in Make: Volume 78.) But arguably, his
most significant and practical invention was the
pendulum clock.
At the time Huygens lived, from 1629 to 1695,
clocks were becoming increasingly important
in daily life, but they were very inaccurate. The
best of them could do no better than gain or lose
more than 15 minutes in time every day. While
a clock like that could tell you when it was time
to eat lunch, it was not suitable for navigation or
astronomical observations.
Inspired by Galileo Galilei’s investigations
of pendulums about 75 years earlier, Huygens
began thinking about how he could use
pendulums to keep better time. Huygens knew
that Galileo had found that pendulums had a
fascinating property: they were isochronous,
meaning that the time it takes for any single
pendulum to swing back and forth is the same
no matter how high the point at which the swing
begins. This made them useful for keeping time
because for a given pendulum length, the time
interval for the swing back and forth is always the
same. When Huygens substituted the constant-
swing-rate pendulum for the imprecise balance
wheel used in clocks up to that point, the error
rate of a Huygens pendulum clock shrank from
15 minutes to 15 seconds a day! This was indeed
a scientific revolution in timekeeping.
In this edition of Remaking History, we recreate
a Huygens-style pendulum clock escapement. An
escapement is the heart of any non-electronic
clock. It’s the mechanism that goes “tick-tock”
and actually keeps time. Because Huygens’
original clock requires accurately cut gears
which are difficult to make, we will instead
build a simpler descendant called a single-pin
escapement clock. The single-pin escapement
isn’t widely used by clockmakers, but it certainly
keeps time, is easy to build, and makes a loud and
satisfying tick-tock when you get it to work.
1. Build the frame for your escapement by
joining the 2×4 and 2×2 boards as shown in
Figure
A
, using 3 deck screws through the
bottom.
TIME REQUIRED:
DIFFICULTY:
COST:
MATERIALS
» Wood boards, 1' long: 2×4 (1) and 2×2 (1)
for the frame
» Wood scraps, ¾" thick: 2"×2" (1) and
3½"×3½" (1) for the pendulum crutch and
escapement block, respectively
» Hardwood dowels, ⁄" diameter: 24" (1) and
6" (1) for lower pendulum and upper pendulum
» Steel bolts, ⁄"×5" (2) and nuts (8) for
pendulum shaft and crank shaft
» Plywood, ¼" thick: 2"×2" square (1) and
1¾"×1¾" squares (2) for the crank and the
escapement wings
» Pan head bolt, #10×1½", with 2 nuts for the
drive pin
» Ball bearings, 608 size (4) from a skateboard
shop, or search online for “608 bearing”
» Twine, 8' length such as mason twine
» Washers, ⁄", a box
» Weight, 8oz for the pendulum. I used a ⁄"
eyebolt with a nut and some washers
» Deck screws, 2½" (3)
» C-clamp
» Tape the less slippery, the better
TOOLS
» Jigsaw
» Electric drill and drill bit set
» Screwdriver bit for deck screws
» Forstner bit, 22mm or ⁄"
» Handsaw
» Glue
1 Day
Easy
$30-$40
WILLIAM GURSTELLE’s book
series Remaking History, based
on his Make: column of the same
name, is available in the Maker
Shed, makershed.com.
101
make.co
Adobe Stock-acrogame, loc.gov/resource - Leupold Jacob
Inner hole:
⁄" dia
Wood frame
7"
Outer hole: ⁄"
wide × ⁄" deep
(both sides)
A
M83_100-103_RemHist_F1.indd 101M83_100-103_RemHist_F1.indd 101 10/11/22 10:36 AM10/11/22 10:36 AM
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