Rapid CADD Training Techniques

Transcription

1 Rapid CADD Training Techniques Warner Richeson, CADD Professor Business, Information & Engineering Technologies Collin College, Frisco, Texas ABSTRACT The purpose of this paper is to describe a technique used to impart Basic CADD training in 24 classroom hours. Many Engineers and Architects are faced with learning AutoCAD or lose business or even lose their jobs. Their situation is serious and immediate. There is no time to acquire necessary skills by enrolling in a semester long course or through a do-it-your-self effort. Training has to be compressed into a short time frame. The classroom techniques used include: a parallel approach that addresses command combinations instead of mastering single commands and practice drawings that deal with editing. Any time wasting activities have to be avoided; however, sufficient hands-on labs are used to put procedures to the test. Lectures are very short and are immediately followed by hands-on exercises. Exercises are progressively more difficult and each reinforces the preceding. This paper will examine, in detail, examples of exercises and show how concepts are addressed in a concurrent manner. Course material is frequently tailored to best meet the needs of the students. And all CADD questions, whether they relate to the immediate subject or not, are addressed in class. Over the 15-year period the course has been offered, students repeatedly have made favorable comments on the exit questionnaire. I. Introduction This Basic CADD course has been offered through Collin County Community College s Continuing Education Division in Plano, Texas since For the prior eight years the course was given on a contract basis to companies such as Texas Instruments and Raytheon. Development of the course started in 1991 as an industrial training course and has continually been refined. Currently AutoCAD 2007 is used; however, the material is not release dependant. And the course has been designed for students with no CADD experience. Most enrollees do, however, have drafting experience or have worked with drawings in their job. Classes are typically made up of Professional Engineers, Architects, Technicians, Draftsmen needing to update skills, and some who are seeking to change professions. Students are presented with an outline of the course including copies of all the drawing projects to be completed in class. A series of prepared practice drawings that concentrate on executing specific editing commands have proven to be an efficient teaching tool. II. Orientation The first task is to acclimate the students to the layout of the screen, command area, toolbars, command aliases, menus, zoom, and pan. It has been observed that students sometimes founder and lose

2 COLLIN COUNTY COMMUNITY COLLEGE WARNER RICHESON 2/4/03 COLLIN COUNTY COMMUNITY COLLEGE WARNER RICHESON 2/4/03 productive time if they do not grasp how to find their way around in the monitor screen environment. Emphasis is put on observing the communications going on in the command area of the screen. Comparing the screen command area usage to that of text messaging with AutoCAD is an analogy that is quickly understood by the young and more mature students alike. III. Getting Started The three coordinate systems absolute, relative rectangular, and relative polar are addressed first, as illustrated in Figures 1, 2, & 3. Addressing these in relatively quick succession has not been confusing for students. On the contrary, they learn that there are choices available and they are not constrained to a single coordinate system. In each succeeding drawing problem, use of the appropriate coordinate system is emphasized Y 1. WRITE DOWN THE X,Y ABSOLUTE COORDINATES OF EACH CORNER. 2. DRAW THE FIGURE USING THESE ABSOLUTE X,Y COORDINATES. Figure 1. Absolute Coordinate Exercise X START A RANDOM X,Y POINT REPRESENTING ONE CORNER. 2. USE THE LINE COMMAND TO DRAW THE FIGURE RELATIVE COORDINATES. Figure 2. Relative Coordinate Exercise Figure 3 RELATIVE COORDINATE EXERCISE START A RANDOM X,Y 1.00 POINT REPRESENTING ONE CORNER. 2. USE THE LINE COMMAND 1.00 TO DRAW THE FIGURE RELATIVE COORDINATES Figure 3. Relative Coordinate Exercise. This paper reviews three typical assignments that demonstrate the parallel approach used in this course. The term parallel approach refers to teaching method that introduces multiple commands in a single drawing assignment. This delivery method challenges students; however, students seem to learn more quickly if they are challenged. The next step applies rectangular relative coordinates, editing commands, layout wizard, and plotting to scale. This may seem to be a giant step but students do rise to the occasion, especially if the assignment relates to real world tasks. Figure 4 shows one of the first drawing assignments. Before doing each assignment students are encouraged to determine the easiest and most efficient methods to complete the assignment accurately. The students are led to observe that there are symmetrical features in the design to exploit. So the mirror tool is introduced to expedite drawing completion. The instructor demonstrates how each of the new drawing tools are used using either overhead projection on a screen or by electronically showing the instructor s drawing image on students monitors. The advantage of using the overhead projection is that students may follow along using their computers where controlling student s monitors insure visibility of the demonstration but may impede student progress.

3 INTRODUCE ARCHITECTURAL DIMENSION STYLE MIRROR THIS SIDE ABOUT MIDPOINT INTRODUCE ARCHITECTURAL UNITS INTRODUCE PLOTTING TO SCALE ELEVATION PRINTOUT PRINTOUT TO SCALE STUDENT NAME DATE COMPLETED 1/8"=1' Figure 4. Mirror Exercise. Figures 5 through 9 illustrate the recommended steps to complete this MIRROR @14'<0 LINE COMMAND Figure 5. Draw Lines. USE TRIM Figure 6. Mirror. MIRROR ABOUT MIDPOINT USE ENDPOINT OSNAPS TO DRAW REMAINING LINE Figure 7. Trim & Lines. Figure 8. Mirror.

4 USE ENDPOINT OSNAPS TO DRAW REMAINING LINES Figure 9. Add Remaining Lines. To finish the drawing students are shown how to setup dimension style, how to use dimensioning tools, how to save their drawing, and how to make a scaled layout with title block. The next project, figure 10, continues to add more complexity through dimensioning, introduces an editing tool, adds a new text style, and polar tracking. Figure 10 USE DIRECT DISTANCE & ORTHO TO DRAW OUTLINE DIMS. ON NEW LAYER INTRODUCE ANGULAR DIMENSIONS USE 45 POLAR TRACKING & FILLET R=0 TO JOIN THE LINES STUDENT NAME ROOF PRINTOUT MAKE NEW TEXT STYLE DATE COMPLETED 1/8"=1 Figure 10. Polar Tracking,Fillet,Text Style.

5 Figures 11 through 12 illustrate the drawing steps and commands taught to complete the assignment. DRAW OUTLINE USING ORTHO & DIRECT DISTANCE POINT & SHOOT SET POLAR TRACKING TO 45 & DRAW SHORT LINES AT EACH CORNER Figure 11. Direct Distance Lines. Figure 12. Polar Tracking. ADD LINES & JOIN USE FILLET WITH TO 0JOIN S Figure 13. Fillet R=0. Figure 14. Lines & Fillet. EDIT DIMENSION STYLE & DIMENSION AS SHOWN Figure 15. Dimension. To finish the drawing, students are instructed how to edit individual dimensions style, how to make a scaled layout with title block, and how to make a dimension layer then edit the dimensions to the new layer. The next assignment incorporates this drawing as an xref. Figure 16 illustrates the next assignment. Before drawing, students are shown how to change linear and angular drawing units; the syntax to draw lines using surveyor angles; how the offset command works; how to load a new linetype; how to use points and point style; and how to setup a dimension style that suppresses dimension lines and extension lines.

6 INTRODUCE SURVEYOR UNITS INTRODUCE OFFSET & LINETYPE INTRODUCE POINTS & POINT STYLE XREF FROM PREVIOUS DRAWING & FREEZE DIM. LAYER INTRODUCE DESIGN CENTER BLOCK INSERTION INTRODUCE OFFSET. Figure 16 Figure 16. Surveyor Unit Project. Figures 17 through 20 illustrate the drawing steps and commands taught to complete the assignment. THIRD COPY THESE LINES USING OFFSET DISTANCE = 10'. FOURTH COPY THIS LINE USING OFFSET DISTANCE = 30'. SECOND ADD TEXT TRIM CORNERS COPY THIS LINE USING OFFSET DISTANCE =66'3-7/16". FIRST Figure 17 Figure 17. Lines & Offset. Figure 18. Linetypes.

7 DRAW THE DRIVEWAY, DIMENSION, AND ADD TEXT XREF DRAWING TO THIS INTERSECTION INSERT BLOCK FROM THE DESIGN CENTER Figure 19. XREF. Figure 20 Figure 20. Dimension & Text. The examples given here are Architectural related but there are several mechanical drawing assignments included at the end of the paper (figures). Examples of practice drawings are also shown (figures) IV. Conclusions Using this method of teaching may appear to be too much-to fast but it has proved to be an effective learning experience. First of all students who sign up for this class are motivated to acquire the skills taught. Secondly, no time is lost or wasted because the course materials are preprinted and each drawing assignment is demonstrated by the instructor. Thirdly, immediately after each demonstration, students start to draw the assignment. Each assignment builds upon the previous one and commands from previous assignments are addressed in each assignment. This repetition helps reinforce retention. Another key to the success of this method is the small class size. The number of students per class range from 3 to 10 with the average size being 5. The course has been offered as three consecutive days or three consecutive Fridays. The outcomes are perceivable different. It is evident that students who practice the assignments out of class do acquire the skills faster and retain them longer. The experience of learning CADD is a lot like learning to swim. One rarely is able to swim the length of the pool after reading a book on swimming techniques. To be proficient one must get in the environment and practice. There has been a steady demand for the class.

8 INTRODUCE COPY COMMAND INTRODUCE ELEPTICAL ARCS INTRODUCE LEADERS INTRODUCE EDITTEXT Q R S T U K L M N P REINTRODUCE OFFSET F A G B H C I D J E PLOT TO SCALE STUDENT NAME DATE COMPLETED 1 4"=1' ELELIPTICAL ARC - OFFSET-COPY DRAW ONE CIRCLE & ONE LETTER ARRAY THE REST INTRODUCE CONTINUE DIMENSI RECTANGULAR ARRAY STUDENT NAME DATE COMPLETED Fi 21 Figure 21. Elliptical Arcs, Offset, &Copy. Figure 22. Rectangular Array. DRAW ONE 16" LINE & ARRAY STUDENT NAME RECTANGULAR & POLAR ARRAYS DATE COMPLETED Figure 23. Rectangular & Polar Array. Figure 24. Complex Areas. Circle, Divide, Trim, Rotate, Make Block Figure 25. 9/12/2001 Project.

9 Figure 26 Figure 26. Gasket Project. Figure 27 Figure 27. Polar Array.

10 Figure 28 Figure 28. Redline Project. Figure 29. Endpoint, Quadrant, Perpendicular, and Midpoint Osnaps.