Engineering Drawing I Carry Prameswari Program Studi Teknik Penerbangan Fakultas Teknologi Kedirgantaraan Universitas Dirgantara Marsekal Suryadarma

Topics Geometric Construction Orthographic Projection Isometric Projection

Geometric Construction

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

Geometric Construction a.Point : -Non dimensional geometrical element. -Occurred by interception of various lines.

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

Geometric Construction c. 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

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

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

ProjectionSymbol First AngleEuropean Third AngleAmerican

Projection Angle

Exercises

QUESTION ???

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