SIMPLE MACHINES, MECHANISMS
AND TECHNIQUES
1
Relating
to the program
Forces
and movements
Simple
machines
Some
notions about drawing
Techniques
and capsules
The
mechanism of motion
The
systems in projects
2
The program…
In the material world, on page 174 of the QEP, you will find…
Learning progression
On page 6 of the learning progression in science and technology
in primary school, you will find:
Still on page 6 in the learning progression for science and
technology, you will also find:
Forces
There are several types of forces. Today we
will look at two, compression and tension.
Generally, forces act on bodies one of two ways:
1. By pushing: This is what is called compression;
2. By pulling: This is what is called tension.
6
Compression
Compression is a force that exerts a push
on a body.
 When this force is applied, it causes or
modifies the motion of the body.
 It may also distort it.

F
F
7
Tension
Tension is the force that pulls a body.
 When this force is applied, it may cause
or modify the motion of the body.
 Finally, it may also cause distortion.

F
F
8
Movements

The mobile parts of a technical object
may move according to three types of
movement.
1.
Rotation
1.
Translation
1.
Helical movement
9
Types of movement
10
Simple machines
Simple machines are machines used to
reduce the force necessary for the
accomplishment of a task.
 Humans have learned to use simple
machines to help in their everyday tasks.
 With an arrangement of simple machines,
we obtain complex machines.

11
Simple machines (continued)

Simple machines serve three main
functions:
1. They
transmit forces;
2. They change the direction of a force;
3. They modify the intensity of the force.
12
Simple machines (continued)

Here are five simple machines:
1. The
lever
2. The inclined plane and the wedge
3. The screw
4. The pulley
5. The wheel, the winch and gears
13
The lever
14
The inclined plane or the wedge
15
The screw
16
The pulley
17
The wheel and gears
18
Some notions about drawing …

For technical drawing, there are international
conventions such as:
◦ Type of line
 Thick
 Medium
 Fine
◦ Basic lines






Visible contour line (thick, continuous line)
Hidden contour line (medium dashed line)
Axis line (fine line with stroke at the center)
Dimension line (fine, continuous line with arrows)
Extension line (fine, continuous line)
Leader line (fine line with one arrow)
◦ Views
◦ Dimensions (in mm)
19
Basic lines
Extension line
Ø8
FACING Ø14 X 3 DEEP
Leader line
50
Axis line
40
13
20
Visible contour line
40°
Dimension line
45
20
80
Hidden contour
line
Basic lines (continued)
Multiple views
Among the six possible
views, we choose to show
those that are necessary to
describe the shape of the
object.
Three views are usually
sufficient to describe an
object. Many simple objects
only require one or two
views.
BACK VIEW
LEFT VIEW
TOP VIEW
FACE VIEW
BOTTOM VIEW
RIGHT VIEW
Making a complex machine
Cartridge
23
A glance at the materials
24
THE LEVER
TEETER-TOTTER
WHEELBARROW
25
WEDGE AND INCLINED
PLANE
NAIL CLIPPER
26
Techniques and capsules
•
Work techniques
•
Safety capsules
27
Construction of a complex machine
Your turn to play…..
28
Movement mechanisms

There are many mechanisms, classified
into two categories:
1. The
transmission of motion;
2. The transformation of motion.
29
Movement mechanisms
1.
Transmission of motion
A transmission of motion mechanism is a
mechanism that transmits the same movement
from one part of an object to another.
Here are three of the most common mechanisms:
Gears;
Friction wheels;
Pulleys and belts.
30
Gears
31
Friction wheels
32
Pulleys and belts
33
Movement mechanisms
(continued)
Your turn to play…..
34
Movement mechanisms
2.
(continued)
Transformation of motion
A transformation of motion mechanism is a mechanism that
changes the nature of the movement, that is from a
translation to a rotation or vice versa..
Here are the transformation mechanisms:





Rod and crank;
Cam and rod;
Rack and pinion;
Nut and bolt;
Crankshaft.
35
Rod and crank
Axis
Crank: Mechanical part by
which a force can transmit a
rotary movement around an
axis.
Rod: Rigid rod that is used
to produce a movement.
36
Cam and rod
Rod or roller: Rigid rod leaned
on the cam.
Cam: Mechanical part whose
function is to push an element
to move it.
37
Rack and pinion
Rack: Straight geared rod.
Pinion: Gear
38
Nut and bolt
Nut: Female part of bolt
Bolt: Threaded cylindrical rod.
39
Crankshaft
Crankshaft: « U » shaped axle with at
least one rod that transforms a rectilinear
movement into a rotary movement.
40
Movement mechanisms
(continued)
Your turn to play…..
41
The systems in projects
Rod and crank: periscope
 Rod and cam: mouse/croc
 Rack and pinion: periscope
 Rod and crankshaft: Mechanical bugs
 Wheels: odometer
 Others…

42
Thank you!
43