121 1208Engineering Drawing I

Carry Prameswari

Program Studi Teknik PenerbanganFakultas Teknologi Kedirgantaraan

Universitas Dirgantara Marsekal Suryadarma

Topics

• Geometric Construction• Orthographic Projection• Isometric Projection

Geometric Construction

Geometric Construction

• Construction of primitive geometric forms (points, lines and planes etc.) that serve as the building blocks for more complicated geometric shapes.

Geometric Constructiona. Point :

- Non dimensional geometrical element. - Occurred by interception of various lines.

Geometric Constructionb. Line : One dimension geometrical element occurred by moving of a point in various direction.

Geometric Constructionc. Plane: - Occurred by at least

three points or connection of one point and one line.

- A plane is always 2D- When the number of

element forming a plane increases, shape and name will change.

Geometric Construction

Relationship of One Line to Another Line or Arc

Bisecting a Line

Dividing a Line into Equal Parts

Orthographic Projection

Orthographic Projection• Reference:

Technical Graphics

• Advantage—Represent features of an object more accurately

• Example problem

Orthographic Projection

• Orthographic projections are a collection of 2D drawings that work together to give an accurate overall representation of an object.

Orthographic Projection

Projection Drawing

• Isometric projection is a method for visually representing three-dimensional objects in two dimensions in technical and engineering drawing.

Multi-view Projection—The Glass Box• Placing parallel planes to the

principal planes forms a glass box (always observed from outside the box)

• To show views of a 3D object on 2D piece of paper, it is necessary to unfold the planes such that they lie in the same plane

• All planes except the rear plane are hinged to the frontal plane, which is hinge to the left-side plane.

Multi-view Projection—The Glass Box

• By unfolding the box, six views of the object are possible

Multi-view Projection—The Glass Box

Multi-view Projection—The Glass Box

Multi-view Projection—The Glass Box

Multi-view Projection—The Glass Box

Multi-view Projection—The Glass Box

Multi-view Projection—The Glass Box

Which Views to Present?

Which Views to Present?

• General guidelines– Pick a Front View that contain the most

information that describe the object– Normally the longest dimension is chosen as the

width (or depth)– Most common combination of views are:• Front, top and side view

– Any other view that is different from the principal views is called an Auxiliary View

Minimum Drawing View

• 3 view• 2 view

Projection Angle

Projection Angle

Projection Symbol

First Angle European

Third Angle American

Projection Angle

Exercises

Exercises

Exercises

Exercises

Exercises

Exercises

QUESTION ???

Thank You