Part 1

Gears
What is a gear?
Counting teeth
Different kinds of teeth
Even more gears
Pulleys are gears without teeth

Shafts and Connectors
Measuring gears
Measuring shafts
Pegs and connectors
Various shafts and connectors

Gear Combinations
Going from small to large gears
Going from large to small gears
Combining gears in different ratios

Gears in a Turntable
Using gears inside the cogs of a turntable

Gears in Series
Many gears in series
Attaching different gears to the same shaft

Angled Gears
Using gears to change the angle of rotation

Worm Drives
Using worm drives

Part 2

Chains and Treads
Transmitting rotational power with chains
Transmitting rotational power with caterpillar treads

Rubber Bands
Various rubber bands
Transmitting rotational power with rubber bands

Rack-and-Pinion Gears
Changing rotational motion into linear motion with rack-and-pinion gears

Moving To and Fro
Translating rotational motion into reciprocal motion

Moving Freely
Transmitting rotational power in any direction

Going the Distance
Transmitting power over distance using many gears
Using chains
Using rubber bands
Using shafts

Part 3

Motors and Gears
Combining motors and gears

Building in Any Direction
Combining pieces so you can build in any direction

Strong Combinations
Making strong combinations!

Two Simple Chassis
What can we make with a simple chassis?
A car with windows
A Formula One racer
An paneled car (with tiles)
A hot rod
What can we make with another chassis?
A car with pipes
A rocket car
A monster car—with claws!
A car with a hood and a trunk

Part 4

Doors
Two doors opened by turning a handle
Swinging doors
A door opened by pushing a plate
An automatic sliding door with a motor and rack gears
A little garage door
A vault door
A door that closes itself
A door with a key
A door that catches like a “real” door
Little car doors
Gull-wing car doors

Pulley Systems
Lifting a load with thread
Various winches
Making your own winches
Simple cranes
The mysterious crane
A crane using chains
The mysterious crane using chains

Rubber Band Power
Launching a rocket with a rubber band
A windup car
A hand-cranked drag racer

More Uses for Gears
Changing the speed between two parallel shafts
Increasing power between two perpendicular shafts
Increasing power between two parallel shafts
Using two crank shafts to move pistons
Always rotating in the same direction
Something like a bug foot
Something like a bird feather
Linear motion with worm gears
Growing and shrinking with worm gears

Making Music
A xylophone
A little guitar
A music box