# Computing with Thread: Part II

## Levers and Cranes

In this class we will explore the potential of levers and cranes for kinetic machines

### The fundamental law of threads

You can pull something with a string, but you can't push it.
That's common sense. And no computer knows it. (Marvin Minsky)

### Threads between two points

Using a threads to transmit information:

• stick: symmetric with respect to push and pull
• thread: pull, yes. push, no.
• Can you build an anti-thread? (i.e. pull no, push no)

### Sliders

Sliders are bars that connect transmit a motion by sliding back and forth

• Getting to know the concept of degrees of freedomn
• How can we make sure a bar only goes back and forth?
• What other constructions can you think of?
• What kind of constraints are imposed by your constructions?

### Levers

Levers are bars that transmit a motion by rotating around a hinge

• What practical applications of levers can you think of?
• Explore different setups and their properties
• How many points are involved, and how are they arranged?
• How many different setups can you find?
• How are the involved forces and distances related?
• Which setups are suitable for which purposes?

### Linkages

Linkages are bars that are connected via hinges.

• how would you create rotating hinges using bars of wood and screws?
• can you create a hinge using thread and what are the limitations?
• create a linkage that can draw interesting curves

## Wheels and Pulleys

In this class we will explore the potential of wheels and pulleys for kinetic machines

## Looms and Logic

In this class we will explore the potential of looms for computing with thread

## Excursion

A trip to Kassel to visit the exhibiton + attend the talk of Ralf Baecker and Georg Trogemann