THAMES & KOSMOS SPRINGBOTS 3 N 1

Build a motorized robot, race car, and countdown timer
— all that run without any batteries or electrical power!
The secret behind these fascinating machines is a power
source called a mainspring — a spiral-shaped spring
that stores up energy when wound up by hand, and
then converts that stored energy back into motion when
it discharges. As you assemble these models one at a
time from over 130 pieces, you will learn about the inner
workings of spring-powered devices like wind-up toys and
ticking mechanical clocks. Discover the physics concepts
of potential and kinetic energy as you experiment with
your spring-powered machines. Easy, snap-together
assembly requires no glue. The kit includes step-by-step
illustrated instructions