Mechinacal toy

EXAMPLE USE OF A CAM

Below is a typical use of a cam. A simple toy based on a cartoon character (Ed the Handyman) is controlled by a cam and follower. As the cam rotates in an anticlockwise direction, the follower falls (diagram 2) and so does the arm of the toy. As the cam continues to rotate the arm begins to rise as seen in diagram 4. The cam shown is a pear shaped cam (named after its shape).

CAM PROFILES


Cams can be shaped in any number of ways and this is determined by the way the follower is to move. The shape of the cam is called the PROFILE. Examples of various cam profiles can be seen below.

Pear shaped cams are used on the shafts of cars. The follower remains motionless for about half of the cycle of the cam and during the second half it rises and falls.

Circular cams or eccentric cams produce a smooth motion. These cams are used in steam engines.

Heart shaped cams allow the follower to rise and fall with ‘uniform’ velocity.

What type of movement do you think this cam profile will give ? Drop cam

Wood

Wood can be classified into:

1) Natural Wood (Solid Wood)

It can be further classified into Hardwood and Softwood.

Hardwood: -Deciduous Trees

- Broad leaves, they shed at certain time of the year

- Flowering

Examples: Jelutong, Dark red meranti , Ramin, Teak, Chengal
Meranti Tree
Softwood: - Coniferous trees

- Narrow, needle-like leaves and do not shed.

- Non-flowering

Examples: Fir, Pine
Pine tree
2) Processed Wood (Manufactured Board)

Examples: Plywood, Medium Density Fibreboard, Hardboard, Chipboard

Plywood

Tools

For Marking out materials

Try Square- Checking squareness using datum references.

Scriber- Marking lines on metal.


Dot punch- For punching small dots along a scribed lin in metals

Marking Gauge- Marking lines parallel to a face side or a face edge on wood.



For cutting/working with materials

Tenon Saw- For cutting staright lines on wood.

Coping Saw- For cutting thin pieces of plastics, including curves


Hacksaw- for cutting straight lines in metals


Wooden Mallet- For striking a firmer chisel


Round File- For filing holes or for enlarging a hole



Triangular File- For filing materials

Materials

Colours

Lines

LINES ___________________ <- that's a line! Lines are probably the basic element of design. They are very useful as they indicate lots of essential information like position, direction, and movement. Today, I will introduce to you the types of lines.1) Vertical lines -demand attention

2) Curved lines- represents smoothness and gentleness

3) Lightning blots and eletrical signals- protray electricity and action
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

4) Wavy lines- convey a flowing movement @@@@@@@@@@@@@@@@@@

Aesthetics

Aesthetics is about the look and feel of a product. The two very important qualities play a very important role when you are selecting a product to buy, as it affects your senses and emotions. For example, when you are buying a sofa, you may ask yourself whether it suits your needs, whether the design looks nice, whether it feels comfortable etc. You will repeat these questions for each sofa, until you are satsfied with one.Aesthetics appeal is not the same for everyone, different people have different likes which may be influenced by the following factors:

1) Lines
2) Shapes
3) Forms
4) Colours
5) Textures