Introduction to Mechanisms, part 1. Wooden Toy Mechanism.

Students assemble mechanism from kit. There are only a couple of ways to do it, see what makes sense.

How do we describe, and thus come to understand, this mechanism?

Simple Machines:

Base: The platform on which the motion takes place. The part that holds all the other parts.

Fixed Parts: Pieces that do not move when the mechanism is used, but that allow other parts to move in controlled ways.

Moving Parts: Pieces that can rotate or slide with respect to other parts.

Bearing Surfaces: The contact between a moving part and a fixed part has to be able to slide easily while providing support for the moving part. Bearing surfaces have to be able to push and slide at the same time.

Pivoting Parts: Lever and Fulcrum, Wheel and Axle, Pulley and Block.

Ramping Parts: Ramp, Wedge, Inclined Plane

Compound Parts: Screw (ramp wound around a pivot to make an axial advance with rotation)

Cam (ramp wound around a pivot to make a radial advance on rotation)

Mechanism Design Basics: Fit Class

Loose

Slip

Press

No Go

Mechanism Design Basics: Geometry

Why must the rocker arm outer hole be slotted, and not round?

Travel Limits make for a mechanism that feels solid, well made.

Binding. 1:3 to discourage binding.

Support Type: Yoke versus Cantilever

[add photos and diagrams to this lesson.]