PROJECTS: TAFF Y PULLING MACHINE
makezine.com/14/taff y
A CONFECTION IN CHAOS
Dr. James Yorke is chair of the mathematics department
at the University of Maryland and the man who introduced
the term “chaos theory” into the popular lexicon. Yorke
explains that the machine manipulates taffy in a unique
form of stretching, free from tight-radius turns and pinch
points.
“In each cycle of the rotors, each 360-degree turn, the
taffy stretches apart by a factor of six,” explains Yorke. “It
becomes six times longer and six times thinner. The taffy
machine carries out this stretching procedure without
ever folding the taffy, without making any kinks or hairpin
points. That’s the feature that attracts us, because in
chaos theory, there are many such situations where we
abstract something that’s stretched and then folded.”
By modeling the stretching involved in taffy pulling,
Yorke and his colleagues forged several important advances in the field of mathematical dynamics.
Understanding those advances involves discussions of
“abstract chaotic dynamical processes” and “the homeomorphism of compact surfaces,” so the layperson desiring
more insight must await a different article written by an
author with a more academic bent than me.
2
1
7
8
1 Bearings
2 Sheaves
3 Gear motors
4 V-belt
5 Wiring terminal
6 Power cord
7 2× 4 lumber
8 1× 8 lumber
9 Front edge of
motor aligned
with back edge
of shelf
10 Front edge of
motor aligned
with front
edge of shelf
4
9
14" (approx.)
24"
6"
10
5"
3
4¾"
7
Illustration by Bill Oetinger
6"
6
5
17"
108 Make: Volume 14
