instrumental drawing

Lettering Instrumental Drawing Geometrical Construction Working Drawing Isometric Drawing

INSTRUMENTAL DRAWINGINSTRUMENTAL DRAWING

MAPUA – DEPARTMENT OF MULTIMEDIA ARTS AND SCIENCES


Various drawing instruments and their correct methods of use for instrumental drawing are illustrated here.

Correct use of these instruments are necessary for efficient and concise drafting.

The students should make it a habit to use these precision instruments correctly.

With the proper use of these tools an accurate representation of shape, relationship, and size can be accomplished.

The instruments dealt with in this topic include most of the basic drafting tools and are sufficient for the initial phases of a technical drawing course.

DRAWING INSTRUMENTS AND ITS USES

Instrumental Drawing



The list of drawing instruments include: 600 mm T-square

45 x 45 and 30 x 60 TriangleProtractorMetric ScaleCompass SetDividersPencilsTechnical PensEraserErasing ShieldCutter, Sharpener, Pencil Pointer or SandpaperDusting BrushFrench CurveCircular Templates

DRAWING INSTRUMENTS AND ITS USESDRAWING INSTRUMENTS AND ITS USES




T-SQUARET-SQUARE

Used to construct horizontal lines.

It also serves as a base for triangles when drawing vertical lines or inclined line.

The T-square has two parts called the blade and the head, which should be joined together.

Drawing Instruments And Its Uses



TRIANGLESTRIANGLES

30 x 60 AND 45 x 45 triangles are used for drawing vertical lines with the T-square as the horizontal support.

15, 30, 45, 60 and 75 lines to the horizontal are constructed by using one or both of the triangles.




Used to measure and draw angles not divisible by 15 when neither the 30 x 60 nor the 45 triangles can be used.

ProtractorProtractorDrawing Instruments And Its Uses



Used to reproduce the dimensions of an object in a full, reduced or enlarged size on a drawing.

Metric ScaleMetric ScaleDrawing Instruments And Its Uses



Used for drawing circles and arcs.

Ink pen can be attached to this compass with the use of special attachment.

Compass types include lengthening bar used for drawing large arcs and circles.

CompassCompassDrawing Instruments And Its Uses



A divider is a type of compass with needle points on both ends and is used for laying off points or transferring dimensions.

It is also used for dividing lines into any number of equal parts.

DividersDividersDrawing Instruments And Its Uses



Graphite lead pencils are the basic instruments used in mechanical drawing and come in varying degrees of hardness.

Drawing pencils are graded and numbered from 6B, very soft and black to 5B, 4B, 3B, 2B, and HB to F, the medium grade; then H, 2H, 3H, 4H, 5H, 6H, 7H, and 8H to 9H, the hardest.

The soft (B) grades are used primarily for sketching and rendering and the hard (H) grades for instrument drawings.

PencilPencilDrawing Instruments And Its Uses



When preparing pencil layouts, select the pencil grade for the line quality required.

Construction lines are drawn with hard grade leads while the final lines are penciled in with a softer lead.

Pencils should always be kept sharp to acquire proficiency and accuracy.

The lead must be rubbed against a sandpaper or pencil pointer to create a long conical point.

To keep the point sharp, rotate the pencil as you draw lines.

The pencil should be used at an angle slightly off the vertical.



PENCILPENCIL


Technical pens are precision inking tools that come with points of varying thickness from 0.10 mm to 2.00 mm depending on the line width required.

These pens have ink cartridges and can be refilled.

Technical Pens And Inking ProcedureTechnical Pens And Inking ProcedureDrawing Instruments And Its Uses



When constructing a line, the technical pen should be in a vertical position.

The angle of inclination and speed must remain constant to obtain a line of uniform width and straightness.

Most faulty lines are due to incorrect pen inclination or by leaning the pen point too close to the straight edge, and it will run under and cause a blot.

If it leans inward, some portion of the point of the pen will not touch the paper and the line will be ragged.

It will not take long to discover that care must be taken when removing T-square or triangle away from a wet ink line.



Technical Pens And Inking ProcedureTechnical Pens And Inking Procedure


There are various kinds of erasers used in drafting.

A hard rubber eraser is used to remove dark heavy lines.

A soft rubber eraser is used to remove light lines and to clean smudges.

Special ink eraser is also available for removing ink lines on tracing paper.

EraserEraserDrawing Instruments And Its Uses



Erasing shields are made of thin flat metal or plastic with cut outs of various sizes and shapes.

An erasing shield restricts the erasing area. In this way, correctly drawn lines will not be disturbed during erasing procedure.

To use, place the shield over the line to be erased and erase through the shield.

Erasing ShieldErasing ShieldDrawing Instruments And Its Uses



These are various tools used for creating sharp conical pencil points.

When sharpening a lead point, care should be taken to keep the graphite away from the drawing.

Most draftsmen keep a cloth or a piece of clay handy to wipe the excess graphite powder from a newly sharpened lead.

Cutter, Sharpener, Sandpaper, Pencil PointerCutter, Sharpener, Sandpaper, Pencil Pointer




It is used to remove loose dirt particles that collect on the drawing.

Removing the dirt with your hands may create smudges on the drawing paper.

Dusting BrushDusting BrushDrawing Instruments And Its Uses



French curves are made of clear hard plastic and are used for drawing non-circular curves.

Points showing the direction of the curve and are penciled in.

Select a portion of the French curve that is most similar to the curve.

Continue shifting the French curve to coincide with the points along the curve.

In shifting the curve, take care to preserve smoothness and continuity and to avoid breaks and cusps.

French Curve And FlexicurveFrench Curve And Flexicurve




The flexi curve is another tool used for drawing irregular curves.

It is made of rubber or plastic outer shell with a flexible metal inner spine.

It can be bent to various shapes and is used in a similar fashion to the French curve wherein points are marked, penciled in and the flexi-curve shifted to suit the curve to be drawn.



French Curve And FlexicurveFrench Curve And Flexicurve


Templates are used for drafting symbols or repetitive figures.

They greatly facilitate drawing speed and precision.

Most templates are made of clear plastic and come in variety of symbols for specialized drawing needs such as curves, hexagons, bolt heads and nuts, circles, thread forms, chemical apparatus, electrical symbols, etc.

TemplatesTemplatesDrawing Instruments And Its Uses



For right handed horizontal line is drawn from left to right.

To Draw Horizontal LineTo Draw Horizontal LineInstrumental Drawing


For left handed horizontal line is drawn from right to left.



To Draw Horizontal LineTo Draw Horizontal Line


Vertical line is drawn upward.

To Draw Vertical LineTo Draw Vertical LineInstrumental Drawing



To draw inclined line at 45 degrees.

45o

To Draw Inclined Line

To Draw Inclined Line



30o

60o

To draw inclined line at 30 and 60 degrees.



To Draw Inclined LineTo Draw Inclined Line


To draw inclined line at 75 and 15 degrees.

75o15o



To Draw Inclined LineTo Draw Inclined Line


To Fasten The Drawing Paper On The Drawing Board

To Fasten The Drawing Paper On The Drawing Board



30 o

60 o



Step 1Step 1Instrumental Drawing


5



60O

45O

30O



instrumental drawing

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