1. Sketching
Sketching is a form of visual communication that is used to quickly record and convey ideas before they are lost.
From UT ME, “Engineering sketching is at the heart of the ideation loop of imagining, sketching and seeing.”

2. Projection

4. Orthographic Projection
Orthographic projection is a means of representing a 3-dimensional object in 2-dimensional media in which the projecting lines are at right angles to the plane of the projection.
Usually a front, side, and plan (top) view are drawn so that a person looking at the drawing can see three main sides at once.

5. Orthographic Projection

6. Glass Box

7. Orthographic Projection

8. Orthographic Projection
There are two ways of drawing in orthographic
First Angle Projection
Third Angle Projection.
They differ only in the position of the plan (top), front, and side views.

9. Third Angle Projection
Third angle projection shows plan, front, and side views.
Plan view is shown first and is above the front and side views.
This symbol denotes third angle projections.

12. Alignment

14. Orthographic Projection
First angle projection is when
the first drawing is the front view, the second is the side view, and last is the plan view.
- Plan view is drawn below the front and side views.
This symbol denotes first angle projections.

15. Orthographic Projection

17. First angle projections
Notice that the image drawn looks like it was “pushed through” the object. Watch the animation again to check.

18. Orthographic Projection

19. General Guidelines

20. Center Lines
Centerlines: Centerlines are thin, long and short dashes, alternately and evenly spaced, with long dashes placed at each end of line
Centerlines are used to represent the axes of symmetrical parts of features, bolt circles, paths of motion, and pitch circles
Every circle, and some arcs, should have two centerlines that intersect at their center of the short dashes – this is the centermark