Architectural Graphics - WORD - 001 - 012.rtf

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Drawing Tools &

Materials

This chapter introduces the pencils and pens necessary for

inscribing lines, the instruments available for guiding the eye and

hand while drawing, and the surfaces suitable for receiving the

hand-drawn lines. While digital technology continues to augment

and enhance this traditional drawing toolkit, hand drawing with a

pen or pencil remains the most direct and versatile means of

learning the language of architectural graphics.

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DRAWING PENCILS

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Pencils are relatively inexpensive, quite versatile, and uniquely responsive to

pressure while drawing.

Lead Holders

¥ Lead holders employ standard 2 mm leads.

¥ The push-button action of a clutch mechanism allows the exposed length

of the lead shaft to be adjusted or withdrawn when the pencil is not in use.

¥ The lead point, which is capable of a variety of line weights, must be kept

well sharpened with a lead pointer.

Mechanical Pencils

¥ Mechanical pencils utilize 0.3 mm, 0.5 mm, 0.7 mm, and 0.9 mm leads.

¥ A push-button mechanism advances the lead automatically through a

metal sleeve. This sleeve should be long enough to clear the edges of

drafting triangles and straightedges.

¥ The relatively thin leads of mechanical pencils do not require sharpening.

¥ 0.3 mm pencils yield very fine lines, but the thin leads are susceptible to

breaking if applied with too much pressure.

¥ 0.5 mm pencils are the most practical for general drawing purposes.

¥ 0.7 mm and 0.9 mm pencils are useful for sketching and writing; avoid

using these pencils to produce heavy line weights.

Wood-Encased Pencils

¥ Wooden drawing pencils are typically used for freehand drawing and sketching.

If used for drafting, the wood must be shaved back to expose 3/4" of the lead

shaft so that it can be sharpened with sandpaper or a lead pointer.

All three styles of pencils are capable of producing quality line drawings. As you

try each type out, you will gradually develop a preference for the characteristic

feel, weight, and balance of a particular instrument as you draw.

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DRAWING LEADS

DRAWING TOOLS & MATERIALS / 3

Recommendations for Grades of Graphite Lead

4H

¥ This dense grade of lead is best suited for accurately

marking and laying out light construction lines.

¥ The thin, light lines are difficult to read and reproduce

and should therefore not be used for finish drawings.

¥ When applied with too much pressure, the dense lead

can engrave paper and board surfaces, leaving grooves

that are difficult to remove.

2H

¥ This medium-hard lead is also used for laying out

drawings and is the densest grade of lead suitable for

finish drawings.

¥ 2H lines do not erase easily if drawn with a heavy hand.

F and H

¥ These are general-purpose grades of lead suitable for

layouts, finish drawings, and handlettering.

HB

¥ This relatively soft grade of lead is capable of dense

linework and handlettering.

¥ HB lines erase and print well but tend to smear easily.

¥ Experience and good technique are required to control

the quality of HB linework.

B

¥ This soft grade of lead is used for very dense linework

and handlettering.

The texture and density of a drawing surface affect how

hard or soft a pencil lead feels. The more tooth or

roughness a surface has, the harder the lead you should

use; the more dense a surface is, the softer a lead feels.

Graphite Leads

Grades of graphite lead for drawing on paper

surfaces range from 9H (extremely hard) to

6B (extremely soft). Given equal hand

pressure, harder leads produce lighter and

thinner lines, whereas softer leads produce

denser, wider lines.

Colored Leads

Nonphoto blue leads are used for guidelines

that will not reproduce on photocopiers.

Nonprint violet leads produce guidelines that

will not reproduce on diazo machines; the lines,

however, may print on photocopy machines.

Test prints are therefore always advisable

when using either nonphoto or nonprint leads.

Plastic Leads

Specially formulated plastic polymer leads are

available for drawing on drafting film. Grades of

plastic lead range from E0, N0, or P0 (soft) to

E5, N5, or P5 (hard). The letters E, N, and P are

manufacturerÕs designations; the numbers 0

through 5 refer to degrees of hardness.

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TECHNICAL PENS

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Technical pens are capable of producing precise, consistent ink

lines without the application of pressure. As with lead holders and

mechanical pencils, technical pens from different manufacturers

vary in form and operation. Most technical pens, however, utilize an

ink-flow-regulating wire within a tubular nib, the size of which

determines the width of the ink line.

There are a dozen point sizes available, from extremely fine

(6 x 0, equivalent to 0.13 mm) to very wide (7, equivalent to 2 mm).

Stainless-steel tips are satisfactory for drawing on vellum but

wear too quickly on drafting film. Tungsten or jewel tips are

required for drafting on film.

A starting pen set should include the following point sizes:

¥ 4 x 0 0.18 mm line width

¥ 0 0.35 mm line width

¥ 1 0.50 mm line width

¥ 3 0.80 mm line width

¥ The tubular point should be long enough to clear the thickness of

drafting triangles and straightedges.

¥ Use waterproof, nonclogging, fast-drying black drawing ink.

¥ Keep points screwed in securely to prevent ink leaking.

¥ After each use, replace the pen cap firmly to prevent the ink

from drying.

¥ When pens are not in use, store them with their tips up.

Digital Stylus

The digital equivalent of the pen and pencil is the stylus. Used with

a digitizing tablet and appropriate software, it replaces the mouse

and enables the user to draw in a freehand manner. Some models

and software are able to detect and respond to the amount of

hand pressure to mimic more realistically the effects of traditional

media.

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T-SQUARES & PARALLEL RULES

DRAWING TOOLS & MATERIALS / 5

T-Squares

T-squares are straightedges that have a short

crosspiece at one end. This head slides along the

edge of a drawing board as a guide in establishing

and drawing straight parallel lines. T-squares are

relatively low in cost and portable but require a

straight and true edge against which their heads

can slide.

¥ This end of a T-square is subject to wobbling.

Parallel Rules

Parallel rules are equipped with a system of cables

and pulleys that allows their straightedges to

move across a drawing board only in a parallel

manner. Parallel rules are more expensive and less

portable than T-squares but enable one to draft

with greater speed and accuracy.

¥ T-squares are available in 18", 24", 30", 36",

42", and 48" lengths. 42" or 48" lengths are

recommended.

¥ A metal angle secured to the drawing board

can provide a true edge.

¥ Use this length of the straightedge.

¥ T-squares with clear, acrylic straightedges

should not be used for cutting. Metal

T-squares are available for this purpose.

¥ Rollers enable the parallel rule to move freely

across a drawing surface.

¥ Transparent, acrylic edges are recommended

for better visibility while drawing lines. Some

models are available with metal cutting edges.

¥ Parallel rules are available in 30", 36", 42", 48",

54", and 60" lengths. The 48" length is

recommended.

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TRIANGLES

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Triangles are drafting aids used to guide the drawing of

vertical lines and lines at specified angles. They have a

right angle and either two 45¡ angles or one 30¡ and

one 60¡ angle.

¥ 4" to 24" lengths are available.

¥ 8" to 10" lengths are recommended.

¥ Small triangles are useful for crosshatching small

areas and as a guide in handlettering. See page 180.

¥ Larger triangles are useful in constructing

perspectives.

¥ The 45¡Ð45¡ and 30¡Ð60¡ triangles can be used in

combination to produce angular increments of 15¡.

See page 19.

¥ Triangles are made of clear, scratch-resistant, nonyellowing

acrylic to allow a transparent, undistorted

view through to the work below. Fluorescent orange

acrylic triangles are also available for greater visibility

on the drafting surface.

¥ Machined edges should be polished for precision and

to facilitate drawing. Some triangles have raised

edges for inking with technical pens.

¥ Inner edges may be beveled to serve as finger lifts.

¥ Keep triangles clean by washing with a mild soap

and water.

¥ Triangles should not be used as a straightedge for

cutting materials.

Adjustable Triangles

Adjustable triangles have a movable leg that is held in

place with a thumbscrew and a scale for measuring

angles. These instruments are useful for drawing such

inclined lines as the slope of a stair or the pitch of a roof.

45¡

45¡ 90¡

30¡

60¡ 90¡

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TEMPLATES

DRAWING TOOLS & MATERIALS / 7

Templates have cutouts to guide the drawing of

predetermined shapes.

Electronic Templates

Drawing and CAD programs include electronic

templates of geometric shapes, furnishings, fixtures,

as well as user-defined elements. The purpose of

physical and electronic templates remains the sameÑ

to save time when drawing repetitive elements.

A significant advantage of CAD programs is their ability

to have a symbol represent all instances of a graphic

element or object in a drawing or design, such as the

dimensions of a window opening or a unit plan in a

housing project. Any change made to the definition or

attributes of that symbol automatically updates all

instances of it throughout a drawing or design project.

¥ Circle templates provide a graduated

series of circles commonly based on

fractions and multiples of an inch.

Metric sizes are also available.

¥ The actual size of a cutout differs

from the drawn size due to the

thickness of the lead shaft or pen tip.

¥ Some templates have dimples to

raise them off of the drawing surface

while inking.

¥ Templates are available for drawing

other geometric shapes, such as

ellipses, as well as symbols for

plumbing fixtures and furnishings at

various scales.

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COMPASSES

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The compass is essential for drawing large circles

as well as circles of indeterminate radii.

¥ It is difficult to apply pressure when using a

compass. Using too hard a grade of lead can

therefore result in too light of a line. A softer

grade of lead, sharpened to a chisel point, will

usually produce the sharpest line without

undue pressure. A chisel point dulls easily,

however, and must be sharpened often.

¥ An attachment allows technical pens to be used

with a compass.

¥ Even larger circles can be drawn by appending an

extension arm or using a beam compass.

¥ A variety of French curves are manufactured to

guide the drawing of irregular curves.

¥ Adjustable curves are shaped by hand and held

in position to draw a fair curve through a series

of points.

¥ Protractors are semicircular instruments for

measuring and plotting angles.

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ERASERS & CLEANING AIDS

DRAWING TOOLS & MATERIALS / 9

Erasers

One of the advantages of drawing with a pencil is the

ability to easily erase pencil marks. Always use the

softest eraser compatible with the medium and the

drawing surface. Avoid using abrasive ink erasers.

¥ Vinyl or PVC plastic erasers are nonabrasive and will

not smear or mar the drawing surface.

¥ Some erasers are saturated with erasing fluid to

erase ink lines from paper and drafting films.

¥ Liquid erasing fluid removes pencil and ink markings

from drafting film.

¥ Electric erasers are very convenient for erasing

large areas and ink lines. Compact, battery-operated

models are especially handy.

Other Aids

¥ Drafting brushes help keep the drawing surface

clean of erasure fragments and other particles.

¥ Soft, granular drafting powder is available that

provides a temporary protective coating over

drawings during drafting, picks up pencil lead dust,

and keeps the drawing surface clean. If used too

heavily, the powder can cause lines to skip, so use

sparingly, if at all.

¥ Pounce powder may be used to prepare drawing

surfaces for inking.

Erasing Shields

Erasing shields have cutouts of various

shapes and sizes to confine the area of a

drawing to be erased. These thin stainlesssteel

shields are especially effective in

protecting the drawing surface while using

an electric eraser. Ones that have squarecut

holes allow the erasure of precise areas

of a drawing.

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SCALES

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In drawing, ÒscaleÓ refers to a proportion determining the

relation of a representation to the full size of that which

is represented. The term also applies to any of various

instruments having one or more sets of precisely

graduated and numbered spaces for measuring, reading,

or transferring dimensions and distances in a drawing.

ArchitectÕs Scales

An architectÕs scale has graduations along its edges

so that scale drawings can be measured directly in feet

and inches.

¥ Triangular scales have 6 sides with 11 scales, a full-size

scale in 1/16" increment, as well as the following

architectural scales: 3/32", 3/16", 1/8", 1/4", 1/2", 3/8",

3/4", 1", 1-1/2", and 3" = 1'-0".

¥ Flat-beveled scales have either 2 sides with 4 scales or

4 sides with 8 scales.

¥ Both 12" and 6" lengths are available.

¥ Scales should have precisely calibrated

graduations and engraved, wear-resistant markings.

¥ Scales should never be used as a

straightedge for drawing lines.

¥ To read an architectÕs scale, use the part of scale

graduated in whole feet and the division of a foot for

increments smaller than a foot.

¥ The larger the scale of a drawing, the more information

it can and should contain.

¥ 1/8" = 1'-0"

¥ 1/4" = 1'-0"

¥ 1/2" = 1'-0"

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SCALES

DRAWING TOOLS & MATERIALS / 11

EngineerÕs Scales

An engineerÕs scale has one or more sets of

graduated and numbered spaces, each set being

divided into 10, 20, 30, 40, 50, or 60 parts to

the inch.

Metric Scales

Metric scales consist of one or more sets of

...

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