Orthographic Projection.docx

LESSON PLAN A DETAILED LESSON PLAN IN ORTHOGRAPHIC PROJECTION I. OBJECTIVES: At the end of the lesson, the pupils will be able to: 1. To understand the basic principle of orthographic drawing. 2. To be able to construct orthographic projection of an objects. 3. To improve students spatial reasoning skills through orthographic projections. II. SUBJECT MATTER:

ORTHOGRAPHIC PROJECTION

A. References: Developed multimedia presentation entitled “Orthographic Projection”. B. Materials: Laptop, LCD Projector, t-square, rule, eraser, pencils, paper, worksheets, Drafting board, various solid objects/pictorial drawing of an object. C. Strategies: Discussion, Multimedia presentation D. Processes: Comparing, identifying and contrasting E. Values Integration: Listening attentively, appreciation and gratitude III. LEARNING STRATEGIES: Teacher’s Activity

Pupils’ Activity

Pre-Assessment Good morning class. Arrange your drawing tables and chairs. Please sit down. Please pass the attendance sheet and sign accordingly.

Good morning ma’am. (Students do what is told them to do).

Review Show video Engineers communicate with each other through drawing. Likewise, as draftsman need to know the theory and principles of a working drawing called orthographic projection. It is through accurate orthographic projection drawing, the designer or draftsman conveys to the carpenter or builder the necessary information to erect and complete a structure or furniture. Motivation Show video

Yes sir.

Do you know how to draw an object?

It composes of lines, figures, text and pictorial drawing.

What is seen in a working drawing? Can you name some of them? Yes, That’s correct! What is needed to make a house? That’s right, A plan or blue print is needed to make an accurate dog house. I have brought a dog house (show to your students a dog house discussing the detailed parts. Without any introduction to technical sketching guidelines, have the students sketched the dog house.) Class you draw a plan of your birdhouse design. See to it that your plan will have “enough detail that someone else can make a similar object". (Collect their drawing). Looking at most of your drawings, I observed that some of you understand the need to show the size of an object. Others emphasize the depth and measurement

A plan or blueprint drawing of the dog house sir.

of the drawing. There is a standardized way to draw a plan like these called orthographic projections, Our lesson for today. Let’s view the PowerPoint presentation on orthographic Projections. Okay, now that you have the basic understanding of what orthographic projections are, let’s do one together. I have here a template. Use this in making your orthographic projections. Activity 1 Give an example of a pictorial object and let your students do the sketch orthographic projection. Allow the students to practice in small groups. Allow the students to work together to answer questions about a real part based on dimensioned sketches (or drawings) of the part. Walk around as they do their activity. Then demonstrate on the board the principles and guidelines in making the orthographic projections. Explain the process as you go to emphasize understanding and comprehension. Activity 2 Distribute the hand out worksheets. Discuss the worksheet to the class. Let the students complete the worksheet independently as the teacher walks around giving assistance where needed. Discuss the answer on the board. Discussion We need to ask ourselves what is Orthographic Projection? Basically it is a way a representing a 3D object on a piece of paper. This means we make the object become 2D.

Orthographic projection allows all views of a three dimensional object to be shown in a two dimensional drawing. If you put all the views together you will have a 2D drawing of all the sides of a 3D object.

First angle projection is a method of creating a 2D drawing of a 3D object. It is mainly used in Europe and Asia and has not been officially used in Australia for many years. The Australian Standard uses third angle projection rather first angle projection as it is easier to understand. Note the symbol for first angle orthographic projection. This is important information for the person interpreting the drawing because if you examine the diagram below you will note that in first angle orthographic projection: Generalization What is an Orthographic Projection? What are the three principal views in an orthographic projection? What are the alphabets of lines used in an orthographic projection? Whys is it important to know about orthographic projections? Application Here's your chance to test your knowledge and ability in Orthographic Projection. Students will complete a three view orthographic drawing of birdhouse with dimensions and specifications. If you wrap up the week by having the students resketch the object from the beginning of the week, there should be some very obvious improvements.

(Students explained their answers.)