Architectural Drafting Fundamentals

VIEWS

Now let's move to the basic drafting equipment

In architecture, ortographic projection is a means of representing an object from a point to infinity. For this reason, the projection lines are paralell to each other and there is no representation of depth. The three principal views in ortographic projection are:

Top
Front
Side

The Top view is comparable to the floor plan of a house, the front and side views are the same as the front elevation, right elevation and left elevation in architectural drawing!

Front

Side

Top

DRAFTING EQUIPMENT

Pencils

Pencils used in architectural drafting are two types: wood and mechanical. The mechanical pencil allows the drafter to change the hardness of the lead and is easier to sharpen. Either one gives the desire results if kept sharpen and used properly.

Technical Pens

Technical pens are use by the drafter to letter and draw straight and curved lines in ink. Pinpoints range from 000 ( very fine) to 8 (about 1/16 in. wide.

In Architecture is not about the pencil, but the lead. You can produce quality drawings using a leadholder, a mechanical pencil and a common wood pencil, but what is more important is which lead you choose:

Erasers

Most drafters prefer to use an eraser not attached to the pencil. Select an eraser that will remove all traces without leaving colored marks. Most of the newest plastic erasers are suitable for this type of work. Electric erasers are preferable by drafters because they quickly erasers large parts.

Erasing Shield

Erasing shields are made of metal or plastic and are usually thin to provide for accurate erasing. Always use the erasing shield when there is a possibility of touching another line that you wish to save.

Drawing Boards

Drawing boards usually come in standardized sizes of 12x18,18x24, 24x36, and 30x42.

Triangles

The most common triangles used in drafting work are the 45 and the 30-60 triangles. They can be made of wood, metal or plastic, but plastic is preferred as it is transparent. Triangles are used specially for drawing lines that are not horizontal. Adjustable triangles can also take place instead of the 45 and 30-60 triangles. However, you must pay close attention to make sure is adjusted accurately.

Protractors

Protactors are used to measure angles. They are produced in circular and semicircular styles. The semicircular type is extensively used by most drafters. Most common protractors are not able to measure finer than half a degree, however, metal protractors with a venier scale will measure accurately to one minute.

Scales

Scales used in three drawings are primarily of three types:

The architect's scale
The engineer's scale
The combination scale

This are made of wood, plastic, metal, or a combination of materials. The architect's scale is usually divided into 3/32, 3/16, 1/8, 1/4, 1/2, 1, 3/8, 3/4, 1 1/2, and 3" to the foot and one edge divided into 16 parts to the inch. The engineer's scale is divided into 10, 20, 30, 40, 50, and 60 parts to the inch. The combination scale is just a combination of the architect's and the ingeneer's scales. It is divided into 1/8, 1/4, 1/2, 1, 3/8, and 3/4" to the foot and 50 and 16 parts to the inch.

How to use a scale:

When the notation at the bottom of the drawing indicates,

Scale: 1/2" = 1'-0"

then the drawing is 1/2 scale. This means that 1/2" on the drawing is equal to 1'-0" on the object.

For example: If you were to draw a house that is 40'x60' at a scale 1/2"=1", you would need a piece of paper a little over 20'x30'.

Most residential plans are drawn at a 1/4 scale, which means that 1/4" in the drawing equals 1'-0" on the house.

Paper

Drafting Paper can be purchased in standard sizes or rolls. The sheets are easy to roll but usually more costly. Most architectural drawings are executed on some type of tracing paper, vellum, or drafting film which provides for ease of reproduction.

Dividers

Architectural drafters use dividers in basically two sizes:

Large (about 6")
Small (about 4")

The small dividers usually have an adjustment wheel in the center or on the other side. The large dividers often have a friction device of some type instead of the wheel.

The dividers are used to divide a line into proportional parts, provide a quick method of measuring a lenght which must be used a number of times. Divider points are sharp like needles, they should be kept sharp to be useful.

Notice that the end 1/4" is divided into twelve parts, which represent the 12 inches of one foot. Be careful not to confuse the 1/4 scale with the 1/8 scale which appear together on the same face. The 1/4 has longer lines denotating each foot.

Use a sharp pencil and be ery careful in pinpointing the exact lenght you wish to measure.

ALWAYS BE ASACCURATELY AS POSSIBLE

The T-Square

T-squares can be made of wood, metal, plastic and combination of these materials. It is used to draw horizontal lines and provide an edge to guide the triangles. The blade is held with the left hand and lines are drawn from left to right (the process is reverse for a left handed person). The T-square should be used on only one side of the drawing since the opposite edge may not be escatly paralell.

Irregular Curves

Irregular curves are used to draw lines that cannot be drawn with the compass. These lines usually have a series of centers and would be very difficult to construct with compass.

When using an irregular curve, line up at least four points and draw the line through three. Continue this process until the line is completed. This procedure produces a smoother line.

The Compass

The compass is produce in many styles an sizes. The most common varieties used by architects are the giant bow (about 6" inch lenght), medium size compass and the smaller center wheel compass.

The compas is used to draw circles, arcs or radii. Lead in the compass should be adjusted to the proper lenght (slightly shorter than the center point) and sharpened to a fine point. Use an F or H lead.