Tech Desc Eng202c

8/9/2019 Tech Desc Eng202c

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The Process of Making anOrthographic Drawing

James Somers3/2/10



Table of Contents

Audience and Scope Page 3

What is an Orthographic Technical Drawing? Page 3

Step 1: Getting a Perspective Page 4

Step 2: Drawing a Sketch Page 5

Step 3: Finalizing the Drawing with Dimensions Page 6

Conclusion Page 7

Works Cited Page Page 8



Audience and Scope

The purpose of this article is to inform high school students that are interested inbecoming engineers of the process of creating an orthographic technical drawingand the practicality it has in their future field of work. The process that I willdescribe can be found in many textbooks in basic engineering. I will try to makethis explanation simple, yet informative, because many high school students willchange their mind about their future career, so I don’t want to get too in depthand bore them.

I also thought about how I liked to learn as a high school student, and realizedthat I liked to get right into the process and then learn the practicality of theprocess at the end. This is why I set-up my paper the way I did.

What is an Orthographic Technical Drawing?

An orthographic technical drawing is a technical document that represents anobject’s size and shape by a series of two dimensional drawings . Many of youhave seen orthographic drawings before in either cartoons or movies. They areusually portrayed as drawings on blue paper (“blue prints”) in movies andcartoons. In figure 1, you can see an example of an orthographic drawing.

Figure 1: An orthographic drawing of the object in the top right



An orthographic drawing has three key steps that engineers must take in orderto create one of their own. The three steps are:

Get a perspective

Sketch the objectFinalize the drawing and add dimensions

Step 1: Getting a Perspective

The first step engineers must take in creating their own orthographic drawing isto get a perspective of the object that they want to draw. Engineers must view

the object as if it were two-dimensional.

Most orthographic drawings only show three views (top, front, and right side)due to symmetry of most objects. The bottom view can be determined from thetop view as well as the other non-drawn sides can be determined from the otherdrawn sides. An engineer would only need to draw any of the other side views if one of the other differs from the other three.

Engineers often view the object as if they were taking a snap shot of the top,front, and right side of the object. If they do this, they would only be able to seethe two dimensional object that is needed to draw. Figures 2 and 3 show how toview a three-dimensional object in 2D.

As you can see in figure 3, the TV remote looks as if it’s only an odd-shaped ovalwith other two-dimensional shapes on it. Once the perspective is established,the next step is to sketch the object.

Figure 2: 3D Image of a TV Remote Figure 3: 2D Top View of the Same Remote



Step 2: Drawing a Sketch

Sketching the object is an important step in creating an orthographic drawing.First, engineers look at the object that is going to be drawn (if it has alreadybeen invented), and sketch the object to somewhat scale so that no lines are not

forgotten. This is important because one forgotten line can turn one object intoa completely different object. For example, if a can was supposed to be drawnin which the top can be pulled off, but a line was forgotten where the can shouldbe cut, the can will require a tool rather than just your hand.

If an engineer is in the process of inventing an item, drawing a sketch is evenmore important. Sketching the idea will give people a picture to see instead of adescription to hear. Sketching the object is also important so that people cansee how the image is going to look before actually putting all the time into thefinished project. Figure 4 shows an example of a sketch of a cell phone.

Figure 4: A sketch of a cell phone before the finished project



Step 3: Finalizing the Drawing and Add Dimensions

The final step in the process of creating an orthographic technical drawing isfinalizing the drawing and adding dimensions. First things first, an engineer has

to complete the drawing.

The engineer must first draw the image to scale. If he is doing this by hand hewill be sure to use the proper tools (T-square, compass, engineering scales,etc.). However if they chose to do this with a computer, they would use AutoCAD. Once the image is drawn, they add dimensions so that the person viewingthe image knows the exact size of the object. Figure 5 shows an example of afinished orthographic technical drawing.

Figure 5: A Finished Orthographic Drawing with Dimensions



Conclusion

Practicality in today’ s life is always important when trying to learn a processbecause everyone wants to know how the process is going to be used. One of the main reasons for learning how to create an orthographic drawing is because

everything is computerized in today’s day and age. If a part, such as a customengine part, is broken and needs to be fixed by another company, an engineermust draw it first. This is because the company then feeds the drawing into themachine and the machine makes the part to the exact specifications of thedrawing.

There are other reasons to learn how to create an orthographic drawing such asinvention. If an engineer is trying to get an idea across to a company, he mustdraw an orthographic drawing so that the company can understand how it looksand so that they can create it. For example, an engineer has an idea for an

object and needs a physical prototype. In order to get the prototypemanufactured he must draw an orthographic drawing of the object, and presentit to the manufacturing company so that they can build it.

An orthographic technical drawing will be used in every engineer ’ s schoolingprocess and in most engineering careers. They will be used as long as inventionsare still being made and custom machined parts are still needed. It is necessary,

as engineers, to learn this skill and apply it to problems of today and the future.



Works Cited Page

Figure 1

http://www.we-r-here.com/cad_07/tutorials/level_3/images/isometric_dwg.gif

Figure 2 and Figure 3

Pictures taken by James Somers

Figure 4

http://farm1.static.flickr.com/145/429228992_67b106d66f_m.jpg

Figure 5

http://www.me.metu.edu.tr/courses/me113/Documents/Exercise_4/orthographic _2.jpg





http://www.me.metu.edu.tr/courses/me113/Documents/Exercise_4/orthographic_2.jpg







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