The Student Will Construct Three-Dimensional Wire Frame Models And/Or Solid Models

Introduction to CAD Assignment #16

Objective: The student will construct three-dimensional wire frame models and/or solid models.

Assignment: Construct each drawing (16-1, 16-2, 16-3, 16-4, and 16-5) as a separate drawing file.

Each drawing assignment is shown drawn as an ORTHOGRAPHIC PROJECTION and/or ISOMETRIC drawing to assist you in visualizing the object and in assigning ELEVATIONS and THICKNESSES. You will be constructing only the top view (Plan View) of each drawing assigning thickness and elevations as needed to create a 3D solid model.

Construct the drawing using layers and colors of your own choice. Use all continuous linetypes. Do not set the limits or insert the border and title block at this time.

To set up a size “A” drawing sheet and for plotting the finished model refer to the “Creating a Layout Tab and plotting the model” section for instructions.

Drawing 16-1 Construct the object shown in drawing 16-1 using the ELEV command to set the elevation and thickness of each element. Be sure to set the elevation and thickness of each element before drawing the element. Use SNAP and GRID instead of OSNAP. Be sure to turn the OSNAP mode off.

You will be constructing the Plan view drawing circles at various elevations and thicknesses. The Elevation view is only used to establish elevations and thicknesses of each element in the model.

Rotate the finished model in space using the ORBIT command and remove the hidden lines using the HIDE command.

Drawing 16-2 Construct the object shown in 16-2 using AutoCAD’s solid modeling features.

Begin by constructing the base of the object using AutoCAD’s draw commands (line, circle, and arc). Editing commands such as Trim, Extend, and Array can be used to complete the base.

Use the PEDIT command to join all of the lines and arcs to form one object. Do not assign a width to the PLINE.

Extrude the base to the correct thickness using the EXTRUDE command.

Add the two circular features using the CYLINDER command.

To form a solid model use the UNION command to join features and the SUBTRACT command to create the hole.

Rotate the finished model in space using the ORBIT command and remove the hidden lines using the HIDE command. Introduction to CAD Assignment #16

Drawings 16-3, 16-4, 16-5 Construct the object shown in using AutoCAD’s solid modeling features.

Begin by constructing the top view (Plan View) of the object. Use the BOX command to construct each rectangular component of the object.

To form a solid model use the UNION command to join features and the SUBTRACT command to remove features.

Rotate the finished model in space using the ORBIT command and remove the hidden lines using the HIDE command.

Creating a Layout Tab and plotting the model Type the command OPTIONS to open the Options Dialog box. The Options dialog box will be displayed on the screen. Select the “Display” tab. In the “Layout Elements” section make sure there are no check marks in the boxes for “Display printable area” and “Display paper background.”

Click OK to close the Options Dialog box.

Select the Layout1 tab. A new screen will appear showing a window with your objects inside the window. Erase the window.

Insert the border and title block in the usual way. Since you are in layout mode it is not necessary to set the limits.

At the command prompt type the command MVIEW. Define a window by selecting the upper left corner and the lower right corner of the drawing area inside the border and title block. Use the OSNAP INT mode to accurately locate the window.

The 3-D model will appear in the drawing area. Switch to model space by typing MS at the command prompt. Rotate the objects to an angle of your choice using the ORBIT command.

Position the objects in the viewing area using the PAN and ZOOM commands. Do not use the MOVE command.

While in model space (MS) and use the HIDE command to hide lines

When the model is centered in the viewing area, switch back to Paper space by typing PS at the command prompt. The drawing is now ready for plotting.

The drawing can now be plotted in the usual way except you will be plotting "Extents" instead of "limits." The drawing must be in the paper space (PS) and not the model space (MS) to plot correctly.

Evaluation: You should have one drawing file and one plot for each model.

Refer to the PROJECT EVALUATION handout for the required items to be turned in for evaluation.

Vocabulary: ELEV ORBIT HIDE PLAN PEDIT EXTRUDE CYLINDER BOX UNION SUBTRACT MVIEW OPTIONS LAYOUT PAPER SPACE (PS) MODEL SPACE (MS)