3.2 Orthographic Projection

• Meaning and purpose of orthographic projection in technical drawing
• The three principal views: front, top and side views
• First angle projection: layout, symbol and reading of views
• Third angle projection: layout, symbol and reading of views
• Differences between first angle and third angle projection
• Orthographic views of shaped blocks: cuboid, L-shape, step, holes and slots
• Hidden detail lines and the line types used in orthographic drawing
• Dimensioning, scales and setting out orthographic drawings

• explain the term orthographic projection as used in technical drawing
• draw orthographic views of shaped blocks in a given projection
• embrace the use of orthographic projection in technical drawing

“What are the applications of orthographic projection in real life?”

“How are orthographic views drawn and read in first and third angle?”

The titles are open to everyone. Reading a lesson needs an account — sign in or create one.

1. Introduction to orthographic projection
   40 min · 1 practice tasks · quiz
   Explain what orthographic projection is and why it is used.
2. The three principal views
   40 min · 1 practice tasks · quiz
   Identify the front, top and side views and what each one shows.
3. First angle projection
   40 min · 1 practice tasks · quiz
   Draw orthographic views in first angle projection.
4. Third angle projection
   40 min · 1 practice tasks · quiz
   Draw orthographic views in third angle projection.
5. Comparing first and third angle
   40 min · 1 practice tasks · quiz
   Compare first angle and third angle projection and read either system.
6. Orthographic views of a rectangular block
   40 min · 1 practice tasks · quiz
   Draw the three views of a rectangular block.
7. Hidden detail lines
   40 min · 1 practice tasks · quiz
   Use hidden detail lines to show edges inside an object.
8. Orthographic views of an L-shaped block
   40 min · 1 practice tasks · quiz
   Draw the three views of an L-shaped block.
9. Orthographic views of a stepped block
   40 min · 1 practice tasks · quiz
   Draw and read the three views of a stepped block.
10. Drawing a block with a hole
    40 min · 1 practice tasks · quiz
    Draw the three views of a block with a drilled hole.
11. Orthographic views of a cylinder
    40 min · 1 practice tasks · quiz
    Draw the three views of a cylinder.
12. Drawing a block with a slot
    40 min · 1 practice tasks · quiz
    Draw the three views of a block with a slot.
13. Dimensioning orthographic views
    40 min · 1 practice tasks · quiz
    Add dimensions to orthographic views so the part can be made.
14. Line types and drawing conventions
    40 min · 1 practice tasks · quiz
    Use the correct line type for each purpose in a drawing.
15. Reading and interpreting orthographic drawings
    40 min · 1 practice tasks · quiz
    Read the three views together and picture the object.
16. Setting out a drawing sheet
    40 min · 1 practice tasks · quiz
    Set out a drawing sheet and draw views to scale.
17. Common errors and checking work
    40 min · 1 practice tasks · quiz
    Identify and correct common errors in orthographic drawings.
18. Applications of orthographic projection
    40 min · 1 practice tasks · quiz
    Describe where orthographic projection is used in real life.