CAD is computer aided design or drafting software that is used to create a a large variety of technical drawing that serve many purposes and can be used in almost any type of application.
In 1970 CAD programs were large mainframe computers that were needed to be housed in in cold dark places that hardly saw the light of day. They were extremely difficult to both operate as well as program. With that being said the program still had many kinks and had extremely limited application and abilities. That this time the development of much smaller and cheaper microcomputers increase which made the systems much smaller in size which increased the access to these programs. Along with making the systems smaller and cheaper the program itself went through some changes that make it easier to use and have more applications.
CAD is used in many different workplace for different reason, it is use for architectural design to plans that will be referred tot during the construction and concept phases of the structure. In automotive design it is used to make the basic shape and look of the car but also is used to make the more efficient such as the aerodynamics of the vehicle. In the automotive industry CAD is also used during the production process to make part accurately and extremely consistently. For industrial design CAD is use to show real world movements and to see if early design is even successful or if parts to to be modified or scrapped all together. This is really a great way to see if the design will even work before any of the production processes even begin. The same application are present for the mechanical industrial as for the industrial and automotive designs.
The way that CAD is used to show different materials is by variations in colors and/or symbols that the programs have to offer. These different colors and symbols tell the person viewing the drawing the difference in what each component if the drawing is made from. In CAD’s ability to show the difference between parts of a drawing it also is able to show the viewer that the capacity or the tolerance of and object or component. CAD programs have very precise functions the have the ability to make distances and dimensions of a drawing very clear and specific, the program uses line, arrows as well as text to communicate this important information. Some CAD programs as so sophisticated that they have the function to take a component of the drawing and show the processes or movements it will make during the use of the produce.
2D CAD software are basic CAD application that have limited functions that restrict their design possibilities to only 2 dimensions or flat drawings.
3D CAD is obviously different from a 2D CAD platform due to the ability to add another dimension to your designs. 3D CAD has the ability to take simple wireframe drawings and create solid 3 dimensional designs that can be viewed and rotated to just about any angle. This software is a great tool to design parts as well as simple 3D house designs.
Even though 2D and 3D CAD software is different in many ways sometimes the information used from either program to create both 2 dimensional or 3 dimensional designs. A lot of time dimensions and views will be used to create three dimensional designs and models of an object. As you can see the the pictures about auxiliary drawings were used to generate the solid three dimensional designs that are show at the bottom right hand of each of the picture.
AutoCAD is a CAD software application that is used for both 2D and 3D design and drafting. AutoCAD was the first CAD software that was able to be ran on a personal computer, this first version of AutoCAD was released in 1982. In the more recent years of AutoCAD has developed function such as 3D tools as well as solid modeling. With these development it has made navigating much easier while in three dimensional making the editing process a great deal easier for 3D models.
CAM is computer aided machining. In this platform of CAD software is manipulated so that a machinist can use the program to either design a specific part or object on the CNC machine itself or upload a design that was already created from a different source. The CNC and CAD software will then break down all of the precise design aspects into a code in which the CNC machine can recognize as different movement in which the machine need to make to duplicate the design into the material that is placed into the machine. This is a way fast and extremely accurate was to mass produce parts the not only have to made to specific dimensions but also very constantly.
CAD increases productivity because it uses technologies that save the operator precious time on drawings because the tools and the program it self are design to be user friendly and to convenient for the user.
The was that drawings that are stored on CAD programs are a benefit for multiple reasons because it not only saves design companies a large amount of space in their workplaces due to the size of hand drawings. Another reason why the drawings being saved on a CAD program is beneficially is because the company has a much more organized way to store their drawings so they can be referred to very quickly and also edited with little easy.
With CAD programs there is a much less margin for error because drawings are done with extremely accurate calculations and measurements. Due to the fact that the operator only needs to enter distances into the program instead of actually drawing certain distances or symbols there is a much lower change of the computer making a mistake on the measurement or calculation.
The reason why the cost of CAD programs are a large disadvantage is because these complex and very powerful programs require a large amount of programming as well as sophisticated software which makes their cost to be relative high.
Expertise aspects to CAD programs is a disadvantage because even though CAD programs brag about how easy their programs are to run and successful operator I have learned not only from research but some experience that they are rather complex and not the easy computer software to operate. Expertise is also a disadvantage because not just anyone has the able to go out and develop a drawing on CAD and it will be a certified design of a product. To become an expert in this field it require a large amount of practice and experience with the program.
Software limitations are another disadvantage to this program because even though these are great programs that seem to be able to do anything, they do have certain abilities that some CAD programs are just not able to achieve.
Technical drawing or drafting is the creating of drawings that show exact specifications to transform and idea into physical form. Sketches are a significant method of communicating graphically.
In 2D drawings takes a 3D object and will take multiple view to show all the dimensions of the object. Three dimensional drawings such as oblique drawing take the flat surface of the paper and use specific technique and shape to make the drawing three dimensional.
Scales are measuring devices that are extremely accurate and also have multiple sides on them with will set distances that are set to different scales. These instruments are use to draw certain objects to scale which will either shrink or enlarge the object accurately.
These pencils and pencils are designed to have great accuracy and meet very specific specification. Examples of this would be .02 lead width for pencils or .25 pen tip width. What makes these precision pens different from regular writing pens is that they have different measuring felt tips instead of most ball point pens. This fragile tip makes different thickness lines that are design not to bleed and create a very smooth and steady line even when traveling over pencil markings.
T-squares are instruments that are used to create perfectly parallel line on a drawing surface. The way that these tools create parallel line is the draftsmen will take the head of the T-square and press is up against the side of the drafting table. The creates a guide that the draftsmen can move up or down to draw straight horizontal lines. Some of the most common lengths for these instruments are 18”, 24”, 30”, 36”, and 42”.
A drafting table is a vital tools used to create these drawings. The primary purpose of these specially designed table is to make the draftsmen comfortable while providing the proper view of what he or she is drawing. On higher end drafting table there is a sliding arm that holds a square that can be adjusted to the degree that the drawing requires.
Triangles are used in drafting for multiple reasons, the most common is to make a perpendicular or a perfectly straight horizontal line. This tool is used with a T-square to create these accurate line. The way a draftsmen with make a perpendicular line is by first pressing the head of the T-square up against the side of a drafting table so that the square is perfectly straight. Then the triangle is placed on the top of the square so that the 90 degree angle is facing the edge of the square. These triangles are also designed so that there are 45, 45, 90 degree angles and also 30, 60, 90 degree angles as well.
The compass is a very sensitive tools which which require not only patience but a steady hand to operate correctly. A compass has a sharp point at the end of one of its arms, this point is used to create a pivot point for the compass to rotate around. At the end of the other arm there is a small piece of lead or an attachment can also be put on the compass so that a pen can be used instead of lead. This end of the compass is used to make the actually circle on the paper. The compass is the used to make perfect circles that have been set to certain distance. One reason why this is such an important and versatile tool is because the compass is also used in certain technique to make all kind of polygon shapes as well as more complex shapes such as ellipses (circles are distorted circle because of the view of the drawing.)
Technical stencils are devices that are use to create specific shapes and symbols very quickly and accurately. These shapes and symbols are commonly used to show the person who is looking at the drawing the location of important items that need to be easily recognized. Stencils are also used to draw these symbols and shapes to scale, an example of this would be most drafting stencils will have toilets and sinks so that the draftsmen can easily show the location and size of these items in relationship to the rooms they are placed in.
These instruments are used while creating a technical drawing when the draftsmen needs to make a complex curve. The odd looking design of the tool makes a guide so that the draftsmen is able to make a smooth and steady curve that a specific drawing might demand.
Exploded view representations are used for three main reasons, one being the number that is used to identify a part. These identification number will inform you of the proper name of the specific part as well as a part number which you would reference to in case you need to replace this part. Exploded views also inform the viewer about how many parts are needed for the object to be assembled properly, this is important information because it will show the person who is assembly the object if he has all the parts needed before he even begin assembly. The third purpose of exploded views is to present the sequence in which each part needs to be assembled to serve its function.
Section drawings are representations of the subject that is being drawing if the subject was “cut” or sectioned off at a point. The main reason behind this type of drawing is to give the person who is viewing the drawing a look at the internal workings of a product. It shows how the parts are placed without disassembling the object. As well as showing the viewer the location of the internal parts of a design it is also use to show other information such as dimensions, material, and also the names of the moving parts.
This is a drawing that is made on a flat piece of paper but it has accurately placed lines in which will be bent or folded to create a three dimensional shape.
This type of drawing is to use multiple 2D drawings from different angle so that you can show a three dimensional object. The three separate 2D views that the person drawing the 3D object will choose normal will consist of a top view, a left view, and also a front view so that the person looking at the drawing will be able to picture the three dimensional object from just these three different views.
These technical drawings are created so that during the construction and/or developmental processes of a produce they can be referred to to answer any basic questions a person might have about a produce. One major reason why these drawings are so crucial is because in the production stages of a produce the company or person who is producing parts for an object might be a long distance from the headquarters in which the produce was design. Due to this communicational barrier the company making the part is sent one of these drawings so that any simple questions can be answered by referring to a working drawing.
These drawings would be used as guides during construction of a produce. The meaning behind these drawings are to give the assembler a view visual representation of the steps as well as the parts need to successful construct a particular object. Though assembly drawings are very similar to exploded drawings the only real difference is that exploded drawings are are a way to view and object while assembly drawings are the actually used as the guide to referred to while assembly a produce.
I will take the time to show and tell the students about the floor plans that I have drawn. I will share my experiences that I’ve gain from taking the time to draw up these plans.
While I have this slide up I will take a few minutes to show the students the plans that I had created on CAD and hopefully answer any questions that they have concerning CAD. I will also share the experiences that I gain from using CAD to develop these drawings.
At the point in my presentation I will give the students a closer look at my scale model. I will answer any questions that they might have and I will break apart the model by each level and hopefully they will be able to see all the small details that I put into this model.
Pull out two major source to talk about to the class. I should tell the students why I found these sources so helpful and why they were vital to the research component of my project.
CAD and Drafting <br />By Josh Davis<br />
Thesis Statment<br />With my project I plan to highlight some of the differences between drafting and using CAD to produce technical drawings. I also hope to show the student the importance of these technical representations.<br />
Personal Relevance<br />The reason why this topic relates to me personally is because I’m very interested in this topic and I have been taking mechanical drawing and advanced CAD classes for the last three years of high school. This topic also relates to me personally because my father owns a construction business in which he often has to to create floor plans and other drawings. He creates these drawings to show potential homeowner and also give estimate but also to give him something refer back to while building some structures.<br />
Definition of CAD<br />CAD<br />http://www.case.com.my/images/jlogo_big.jpg<br />http://www.caddprimer.com/cad_graphic_design_books.gif<br />
History of CAD<br />1970<br />CAD programs are hardly used<br />Late 1970’s<br />Development of smaller and less expensive microcomputers<br />1980’s<br />AutoCAD<br />1985<br />First specifically based solid 3D program<br />Late 1990’s<br />“dot-com boom and the internet”<br />Late 1990’s to today<br />Anonymous. “30 Years of CAD/CAE Software.” NASA Tech Briefs. 01 Jan 2006. 13. eLibrary. ProQuest LLC. UPPER MERION AREA HIGH SCHOOL. 02 Dec 2009. http://elibrary.bigchalk.com.<br />
Applications of CAD<br />Architectural design <br />Automotive design<br />Industrial design <br />Mechanical design<br />Special effects <br />Computer animation<br />http://www.planetpdf.com/images/5_Reduce_Model_Dialogue_with_Piston100.jpg<br />Computer control programmer and operators. Occupational Outlook Handbook 2006-2007. U.S. Bureau of Labor statistics. 2006. eLibrary. ProQuest.LLC. UPER MERION AREA HIGH SCHOOL. 02 Dec 2009. <http://elibrary.bigchalk.com><br />
Different Platforms of CAD<br />2D CAD<br />http://www.kdh.ltd.uk/templates/kdh/images/_fullsize/2d-floorplan-after-cad.jpg<br />
Platforms of CAD<br />3D CAD (solid)<br />http://www.prlog.org/10452787-low-cost-3d-cad-modeling-services.jpg<br />http://farm3.static.flickr.com/2655/4157827590_0d47764600.jpg<br />
Platforms of CAD<br />2D CAD and 3D CAD<br />http://pressbox.co.uk/images/logos/311578_MEDUSA4_Personal_free_2D_3D.jpg<br />http://www.cor-creative.com/COR-CAD/Images-Samples/3D-CAD-samples/COR_3D_CAD-sample2.jpg<br />
Platforms of CAD<br />AutoCAD<br />http://www.jtbworld.com/images/AutoCAD_2009_splash.jpg<br />http://www.jtbworld.com/images/AutoCAD_2009_splash.jpg<br />
Different Platforms<br />CAM<br />http://www.andrew.cmu.edu/user/sahuber/rpd/Pictures/Real%20CNC%20mill.JPG<br />http://www.mmec.net/Hass_CNC_Milling_machine.jpg<br />
Advantages of CAD<br />Speed<br />http://www.inition.co.uk/inition/images/product_3Dinput_3dconnexion_spacetraveler2.jpg<br />http://develop3d.com/images/articles_fullwidth/SpacePilot-Pro-large.jpg<br />
CAD Advantages<br />Drawings are stored on hard drives<br />http://www.pc-recovery.co.uk/images/hard-drive.jpg<br />
CAD Advantages<br />Lower margin for error<br />http://www.wwu.edu/depts/tutorialcenter/images/calculator.gif<br />http://www.eschoolnews.com/media/images/math_image.jpg<br />
Advantages I experienced<br />Instant calculations<br />Copy and move pre-drawn section of a drawing with easy <br />Ability to make copies and print<br />
Disadvantages to CAD<br />Cost <br />http://makemoney99.com/wp-content/uploads/2008/12/make-money-online.jpg<br />
“Working” drawings<br />Drawings that are referred to during the developmental or construction stage of a produce<br />Civil <br />Architectural <br />Structural <br />Plumping<br />System<br />Electrical <br />Etc.<br />Thilmany, Jean. “Pros and Cons of CAD.” Mechanical Engineering. 01 Sep 2006. 38. eLibrary. ProQuest LLC. UPER MERION AREA HIGH SCHOOL. 02 Dec 2009. <http: elibrary.bigchalk.com><br />
Assembly drawings<br />Use to show the assembly process of a produce in which parts are numbered to show their placement <br />http://www.gentechdesign.com/images/enlargements/Assembly-Drawing.jpg<br />
Work Cited<br />Coen-Brown, Karen L. Understanding Microstation/J. New Jersey: Prentice Hill, 2001.Pag. Print. <br />French, Thomas E, Carl L Svensen, and Jay D Helsel. “Symbols.” Mechanical drawing. Tenth Edition ed. New York: Mcgraw-Hill Book Company, 1985. 494-495. Print<br />Thilmany, Jean. “Pros and Cons of CAD.” Mechanical Engineering. 01 Sep 2006. 38. eLibrary. ProQuest LLC. UPER MERION AREA HIGH SCHOOL. 02 Dec 2009. <http: elibrary.bigchalk.com><br />“Software/Hardware.” Design News. 11 2003. 90 eLibrary. ProQuest LLC. UPPER MERION ARE HIGH SCHOOL. 02 Dec2009. <http://elibrary.bigchalk.com>. <br />Haftl, Lawrence. “There is CAD, and then there is CAD.” American Machinist. 01 Sep 2008. 24. eLibrary. ProQuest LLC. UPPER MERION AREA HIGH SCHOOL. 02 Dec 2009. <http://elibrary.bigchalk.com>. <br />Computer control programmer and operators. Occupational Outlook Handbook 2006-2007. U.S. Bureau of Labor statistics. 2006. eLibrary. ProQuest.LLC. UPER MERION AREA HIGH SCHOOL. 02 Dec 2009. <http://elibrary.bigchalk.com><br />Anonymous. “30 Years of CAD/CAE Software.” NASA Tech Briefs. 01 Jan 2006. 13. eLibrary. ProQuest LLC. UPPER MERION AREA HIGH SCHOOL. 02 Dec 2009. http://elibrary.bigchalk.com.<br />http://elibrary.bigchalk.com/elibweb/elib/do/document?set=search&dictionaryClick=&secondaryNav=&groupid=1&requestid=lib_standard&resultid=1&edition=&ts=2BC4C82FD1F1E33EF3A0EB4DFEB0553A_1272030100510&start=1&publicationId=&urn=urn%3Abigchalk%3AUS%3BBCLib%3Bdocument%3B119734758<br />http://elibrary.bigchalk.com/elibweb/elib/do/document?set=search&dictionaryClick=&secondaryNav=&groupid=1&requestid=lib_standard&resultid=6&edition=&ts=2BC4C82FD1F1E33EF3A0EB4DFEB0553A_1272030467258&start=1&publicationId=&urn=urn%3Abigchalk%3AUS%3BBCLib%3Bdocument%3B98514873<br />http://elibrary.bigchalk.com/elibweb/elib/do/document?set=search&dictionaryClick=&secondaryNav=&groupid=1&requestid=lib_standard&resultid=66&edition=&ts=2BC4C82FD1F1E33EF3A0EB4DFEB0553A_1272030679400&start=51&publicationId=&urn=urn%3Abigchalk%3AUS%3BBCLib%3Bdocument%3B115501807<br />McGraw-Hill, Glencoe. Basic Technical Drawing. 8th Edition ed. 622 vols. N.p.: Glencoe/McGraw-Hill, 2003. Print. <br />Roy, M. Raja. Engineering Drawing (with Auto CAD). N.p.: I K International Publishing House, 2009. Print.<br />
Work Cited<br />Roy, M. Raja. Engineering Drawing (with Auto CAD). N.p.: I K International Publishing House, 2009. Print.<br />Monahan, James. "Drafting As An Art Of Technical Drawing." Articles Base. N.p., n.d. Web. 11 Mar. 2010. <http://www.articlesbase.com/careers-articles/ drafting-as-an-art-of-technical-drawing-8047.html>. <br />Aniston, Kelvin. "Mechanical 2D Drafting and Mechanical 2D Drawing." Articles Base. N.p., n.d. Web. 7 Mar. 2010. <http://www.articlesbase.com/ business-articles/ mechanical-2d-drafting-and-mechanical-2d-drawing-1247780.html>.<br />West, Andy. "Experience Is Important In Computer Aided Drafting." Articles Base. N.p., n.d. Web. 10 Mar. 2010. <http://www.articlesbase.com/ education-articles/ experience-is-important-in-computer-aided-drafting-286282.html>. <br />Thomas, Mike. "Structural Drawings." articlesbase.com. N.p., n.d. Web. 10 Mar. 2010. <http:www.articlesbase.com/business-opportunities-articles/ structural-drawings-precise-structural-engineer-for-building-structure-design-1079449.html>. <br />
Class Activity<br />After splitting the class up into two separate groups each team will be give materials create a small pretzel cabin.<br />The objective is to build the model faster and hopefully more accurately than the opposing team. <br />Have fun and good luck<br />
Conclusion<br />I hope that after presenting this information I was able to share some information that is not only new to the students but also interesting. Also I hope that I was able to take the information present in my drawings and give the class a real idea of what exactly is being shown in the drawingsand the importance and meanings behind these drawings.<br />