Understanding Structures and Mechanisms:
From Frames to Cranes
A Hands-on Workshop for
Primary-Junior-Intermediate
Science and Technology Teachers
Susan Sitter
Terry Wilkinson
Richard Michaud
OCTE Conference 2009
Technological Problem Solving
Critical aspects:
• careful planning;
• purposeful selection of tools and materials;
• testing, retesting, and modifications of a
product or process;
• communicating about the solution;
• recommending changes or improvements.
www.technologyiselementary.com/?q=node/1
T P S Skills Continuum
T P S Skills Continuum
T P S Skills Continuum
Goals of the S & T Curriculum
1. to relate science and technology to
society and the environment
2. to develop the skills, strategies, and
habits of mind required for scientific
inquiry and technological problem solving
3. to understand the basic concepts of
science and technology
Grade 1 – MATERIALS, OBJECTS, AND
EVERYDAY STRUCTURES
• Objects have observable characteristics
(e.g., texture, height, shape, colour)
and are made from materials
(e.g., wood, plastic, steel, paper, polystyrene
foam, cloth).
• Materials have specific properties
(e.g., rigid, flexible, solid, and smooth).
Grade 1 – MATERIALS, OBJECTS, AND
EVERYDAY STRUCTURES
• An object is held together by its structure
(i.e., a supporting framework).
• The materials and structure of an object
determine its purpose.
Structures are made from materials that are well
suited for the tasks they do (e.g., sandpaper is
rough to help take the rough edges off wood).
Supporting frameworks
Grade 2 – MOVEMENT
• Movement is a change in the position of an
object (e.g., turning, spinning, swinging,
bouncing, vibrating, rolling).
• Simple machines help objects to move
(e.g., by pushing, by pulling, by dropping).
A pulley is a groovy wheel
Rolling Frame
Grade 2 – MOVEMENT
• Mechanisms are made up of one or more simple
machines.
(i.e., using a ramp allows people in wheelchairs
to move from one level to another; using a pulley
makes it easier to lift a load).
• Simple machines and mechanisms make life
easier and/or more enjoyable for humans (e.g.,
using a wheelchair allows people with disabilities
to be more independent).
Grade 3 – STRONG & STABLE STRUCTURES
• A structure has both form and function.
What are some structures that we see or use
every day that we depend on to be strong and
stable?
What is the positive and negative impact of
homes, shopping plazas, playgrounds, and
bridges built by humans?
Grade 3 – STRONG & STABLE STRUCTURES
• Structures are affected by forces acting on them.
What is the effect of adding weight to the base of
a tower on the stability of the tower?
• Structures need to be strong and stable to be
useful.
Triangulation or cross-members can improve a
structure’s strength. Stability is improved by
lowering the centre of gravity.
Grade 3 – FORCES CAUSING MOVEMENT
• There are several types of forces that cause
movement.
Magnetism, muscular force, gravitational force,
or friction can cause an object to start, stop,
attract, repel, or change direction.
Design and build devices that use forces to
create controlled movement (e.g., a crane that
lifts a load).
Crane with Winder
Grade 4 – PULLEYS AND GEARS
• Pulleys and gears change the speed, direction,
and motion of, and force exerted on, moving
objects.
• Pulleys and gears make it possible for a small
input force to generate a large output force.
Design, build, and test a model drawbridge for a
castle.
Swinging Frames
Further connections
• Grade 4 – ROCKS AND MINERALS
• Grade 5 – FORCES ACTING ON
STRUCTURES & MECHANISMS
• Grade 6 – ELECTRICITY AND ELECTRICAL
DEVICES
Grade 7 – FORM AND FUNCTION
• Structures have a purpose. A crane is a lifting
machine that can be used both to lift and lower
materials and to move them horizontally.
• The form of a structure is dependent on its
function. The structural design of a crane is
dependent on location and purpose.
Grade 7 – FORM AND FUNCTION
• The interaction between structures and forces is
predictable.
The centre of gravity of a structure affects the
structure’s stability.
Faulty construction, foundation failure, &
extraordinary loads can cause cranes to
collapse.
Grade 8 – SYSTEMS IN ACTION
• Systems are designed to accomplish tasks.
Cranes are commonly employed in the transportation,
construction and manufacturing industries. These
industries impact both positively and negatively on
society, the economy, and the environment.
• All systems include an input and an output.
Cranes use one or more simple machines to create
mechanical advantage (i.e., lever, pulley, hydraulic
cylinder).
UNDERSTANDING STRUCTURES
AND MECHANISMS
Picture Frame (Sue)
Drawbridge (Terry)
Hydraulic Crane (Rick)