1st and 3rd angle projectionBy Dr. Mahdi Damghani

What is a 1st angle and 3rd angle orthographic projection???

Orthographic Projection requires you to draw each of the three views of the object separately. You have to project each view by imagining that you are looking at 900 to each plane in turn. What you see is drawn on the plane behind the object. This will be difficult at first but with practice it will become easier.

1st angle

3rd angle

Where does the symbol for 1st angle and 3rd angle orthographic projection come from???

Brief introduction to BS8888???

A number of different standards have been developed within the last century, one of which is British Standard (BS) 308 Pt 1, 2 & 3. Like many other standards, BS 308 has seen numerous alterations and revisions. Considering the globalisation, it was essential to have a single standard that was recognised internationally. Hence, the International Standards Organisation (ISO) has combined and improved the individual standards into one BS 8888:2004 Technical Product Document.

Kit 1 Kit 2 Kit 3 Kit 4 2004

General Principles Tolerances and Dimensioning Computer Aided Engineering Design Management Added Standards

A series paper size based on BS8888???

Border and title block based on BS8888???

Border is drawn 10mm in from the edge of the paper extending along all four sides. Everything inside the border is deemed to be part of the drawing and, by definition, is part of the contract requirements is legally binding. Title Block should be included at the bottom right-hand corner of the sheet. It includes all the information to enable interpretation, identification and archiving of the drawing.

Type of Drawing (Gen Arrangement, Detail, etc) Name (Who produced the drawing)

Title

Projection Symbol

Date (Revision dates) General Tolerance Who does the drawing belong to Scale Drawing Number (ID number) Revisions

Scales based on BS8888???

Drawing lines based on BS8888??? Lettering and numbers based on BS8888???

Line A

Description Continuous thick Continuous thin

Usage Visible outlines and edgesDimensions, projections and leader lines, hatching, outlines of revolved sections, centre lines, imaginary intersections.

B

C

Continuous thin irregular Continuous thin straight zigzas Dashed thin Chain thin Chain thin, thick at ends or changes of direction Chain thin with double dash

Limits of partial or interrupted views and sections.

D E F G H

Hidden outlines and edgesCentre lines, lines of symmetry, trajectories and loci, pitch lines and pitch circles.

Cutting planesOutlines and edges of adjacent parts, positions of moveable parts, pattern lines.