Chapter 1 AL Inventor Design Philosophy Create parametric designs •u Get the “feel” of Inventor •u Use the Inventor graphical interface •u Work with Inventor file types •u Move from AutoCAD to Inventor •u Create 3D virtual prototypes •u Use functional design GH TE D •u MA TE RI In this chapter, you will be introduced to the concept of parametric 3D design and the general tools and interface of Inventor.
| Chapter 1 Inventor Design Philosophy For instance, if you were to sketch four lines to define a rectangle, you would expect two dimensions to be applied, defining the length and width. But you would also need to use 2D sketch constraints to constrain the lines so that they would stay perpendicular and equal to one another if one of the dimensions were to change.
Understanding Parametric Design Figure 1.3 Adding features to complete the part model Using the Part in an Assembly Just as well-constructed parts start with well-constructed sketches, well-constructed assemblies start with well-constructed parts. Once the part model is built up from the features you create, you can use it in an assembly of other parts created in the same manner.
| Chapter 1 Inventor Design Philosophy How would the holes be affected? Should they stay in the same place? Or should they stay at some defined distance from one end or the other? Anticipating changes to the model is a large part of being successful with Inventor. Imagine, for instance, that a simple design change required that the pivot link become 50 millimeters longer on one leg.
Understanding Parametric Design •u X Axis, the axis running in infinitely in the X direction •u Y Axis, the axis running in infinitely in the Y direction •u Z Axis, the axis running in infinitely in the Z direction •u Center Point, the point found at zero in the X, zero in the Y, and zero in the Z directions When creating the base sketch of a part file, you typically start on one of the origin planes.
| Chapter 1 Inventor Design Philosophy Parametric AutoCAD Starting with AutoCAD 2010, you can create 2D parametric dimensions and constraints much as you can in Inventor. Driving Dimensions The workflow in Inventor sketching is substantially different from that in traditional AutoCAD, even beyond dimensions. In Inventor, you create sketches in 2D and then add geometric constraints such as Horizontal, Vertical, Parallel, and so on to further define the sketch entities.
Understanding Parametric Design rectangles dimensioned at an angle defines the basic shape and is much easier to sketch and fully constrain than the finished shape would be. If the idea of simple sketches seems not to fit the type of design you do, understand that most any design will benefit from the simple-sketch philosophy.
| Chapter 1 Inventor Design Philosophy For instance, to create the base feature for the pivot link, you would create a sketch on a default origin plane, such as the XY plane. Because the XY origin plane is included in every part file and cannot be changed, your base feature is stable and independent of any other features that may follow. To create a hole in the base feature, you would typically select the face of the base feature to sketch on.
Understanding Parametric Design game, you had to knock down all of the bottles. However, if the bottle in the center on the bottom were nailed down, it would be impossible to win the game, and as a matter of physics, it would be difficult to knock down the bottles next to it. Having a grounded component in your assemblies, one that is “nailed down,” will likewise keep your assemblies from falling over as you build on to them.
| Chapter 1 Inventor Design Philosophy to constrain to in the assembly and it will be much more stable. However, if you constrain the parts by selecting model features, you run the risk of constraints failing once a revision to a part changes or removes the originally referenced geometry. To build a completely “bulletproof” assembly, you could constrain the origin geometry of each part to the origin geometry of the assembly.
Understanding the “Feel” of Inventor | When you work with assemblies, the active tab changes to the Assemble tab (as shown in Figure 1.10), allowing you to place components, create new components, pattern them, copy them, and so on. There are also a number of other tabs shown that you can manually switch to (by clicking on them) at any time to use the tools they contain. Figure 1.
| Chapter 1 Inventor Design Philosophy Drawing in AutoCAD Becomes Sketching in Inventor The fundamental difference between traditional AutoCAD and Inventor is that in AutoCAD you draw and in Inventor you sketch. This difference sounds subtle, but it is very important. In AutoCAD, you likely construct lines precisely to specific dimensions to form the geometry required.
Using the Inventor Graphical Interface Using the Inventor Graphical Interface The Inventor graphical interface might be different from what you are accustomed to in other general software applications and even different from other design software. In Figure 1.12, you see the entire Inventor window, which shows an assembly file open for editing. Figure 1.
| Chapter 1 Inventor Design Philosophy Table 1.1 defines all the Quick Access bar icons available for the different file types. Table 1.1: Icon Quick Access Bar Icons Definition The New icon launches the New File dialog box. The drop-down list allows you to create a new part, assembly, drawing, or presentation file using the standard templates. The Open icon launches the Open dialog box. It displays a location defined in your active project. The Save icon saves the file.
Using the Inventor Graphical Interface Table 1.1: Quick Access Bar Icons (continued) Icon Definition The Design Doctor icon launches a dialog box that helps you diagnose and repair issues with a file. It is grayed out unless there is an issue. The Update All Sheets icon is used in the drawing environment to update all the sheets in a drawing at once. The Parameter icon is used to access the parameters table, where you can rename, change, and create equations in dimension and design parameters.
| Chapter 1 Inventor Design Philosophy Exploring the ViewCube The ViewCube, shown in Figure 1.15, is a 3D tool that allows you to rotate the view. Here are some viewing options: •u If you click a face, edge, or corner of the ViewCube, the view rotates so the selection is perpendicular to the screen. •u If you click and drag an edge, the view rotates around the parallel axis. •u If you click and drag a corner, you can rotate the model freely.
Using the Inventor Graphical Interface | A Look at the Navigation Bar Continuing with the interface tour, you’ll see the navigation bar located on the right side of the graphics window. At the top of the bar is the steering wheel. Below the steering wheel are the other standard navigation tools: Pan, Zoom, Orbit, and Look At. Figure 1.16 shows the navigation bar. Figure 1.16 The navigation bar You can use the navigation bar’s steering wheel to zoom, pan, walk, and look around the graphics area.
| Chapter 1 Inventor Design Philosophy The Ribbon Menu The Ribbon menu is similar to the one introduced in Microsoft Office 2007 in that it is composed of tabs and panels. Each tab contains panels for a particular task, such as creating sketches, and each panel contains related buttons. As previously mentioned, the Ribbon will change to the proper tab based on the current task (for example, sketching brings up the Sketch tab), but you can select a different tab as needed.
Using the Inventor Graphical Interface Figure 1.18 The View tab The Visibility panel has tools for controlling which objects are visible. When you click Object Visibility, a large list is displayed so you can control the appearance of objects in your graphics window. The Appearance panel has tools for controlling the way models are displayed. You can switch between orthographic (parallel model lines appear parallel) and perspective (parallel model lines converge on a vanishing point) views.
| Chapter 1 Inventor Design Philosophy Using a perspective view may be desirable when viewing the model in a 3D view, but it can be distracting when sketching on a flat face or viewing the model from a standard 2D orthographic view because you see what appear to be tapering faces and edges.
Using the Inventor Graphical Interface Using the Browser In this section, you will explore the behavior of the browser pane when working in Inventor by opening an assembly and making a change to one of its parts: 1. In the Get Started tab, click Open. 2. To ensure that you are looking at all the files in the Mastering Inventor 2012 project (and only the files in this project), click Workspace in the Open dialog box (see Figure 1.19). Figure 1.19 Opening a file from the Chapter 01 folder 3.
| Chapter 1 Inventor Design Philosophy When an assembly file is open, the Assemble tab of the Ribbon bar is active. You’ll notice that in the Model browser (to the left of the screen), all items are shown in a white background, with no portion of the Model browser grayed out. You are currently in the top level of the assembly, meaning that the uppermost level of the assembly is currently active and ready for edits. 4.
Using the Inventor Graphical Interface | Edit a Part You’ll continue with the exploration of the browser by setting a part file active for edits and making a change to a part feature: 1. In the browser, double-click the part called Face_Plate_mi_1 to set it active for edits. If you hover for a moment over the icon, the plus sign may automatically expand; you can disregard that and just double-click the icon.
| Chapter 1 Inventor Design Philosophy Four Ways to Use EOP Markers Because part features are listed sequentially, in the order they were created, the EOP marker allows you to figure out how a part was constructed. It can also be used to reorder features, repair a part, and compress a file size for emailing or posting online. Here are four ways to use EOP markers: •u Dragging the EOP marker to the top and then dragging it down one feature at a time re-creates the part.
Using the Inventor Graphical Interface | Figure 1.21 Editing the faceplate Notice that the faceplate is pulled back against the frame. This is the power of a parametric model. Because the arbor press assembly has parameters defining the mating constraints of the faceplate and frame, it automatically adjusts to the change you made by holding those parameter values.
| Chapter 1 Inventor Design Philosophy When the Style And Standard Editor dialog box opens, the styles collection relating to the assembly file appears, as in Figure 1.23. You will notice that while working with an assembly (or part), three style areas are available: Color, Lighting, and Material. Figure 1.23 The Inventor Style And Standard Editor dialog box (assembly mode) 4.
Learning the File Types in Inventor | offered and suppressed depending upon the task at hand. You can close the drawing file you have open without saving changes and continue on to the next section. Figure 1.25 Compare the available options for these two extrude dialog boxes. Learning the File Types in Inventor In AutoCAD, you might be accustomed to having the DWG (.dwg) file format as your primary file format; in Microsoft Word you will use primarily just a DOC (.
| Chapter 1 Inventor Design Philosophy Table 1.3 lists the filename extensions for the file formats commonly used in Inventor: Table 1.3: Common Filename Extensions in Inventor. Extension Description Use .ipj Inventor project file Used to manage file linking paths .ipt Inventor single part file Used to create individual parts .iam Inventor assembly file Used to assemble parts .ipn Inventor presentation file Used to create exploded views of assemblies .
Learning the File Types in Inventor | Working with DWGs You can use DWG files in a number of ways in Inventor. Although Inventor does not support the creation of AutoCAD entities, you can utilize AutoCAD geometry in Inventor sketches, Inventor drawings, title blocks, and symbols. When creating a new part file in Inventor, you can copy geometry directly from an AutoCAD DWG and paste it into an Inventor sketch. AutoCAD dimensions will even be converted into fully parametric Inventor dimensions.
| Chapter 1 Inventor Design Philosophy Another aspect of working with an Inventor DWG in AutoCAD is that whereas the Inventor DWG does not contain a model space by default, once it is opened in AutoCAD, you can access model space. From model space in an Inventor DWG, you can use the Insert command to place the Inventor drawing views of the model as AutoCAD blocks. These blocks will update automatically as long as they are not exploded and remain in the current DWG.
3D Models vs. 3D Virtual Prototypes •u Determine whether your current computer hardware and network are up to the task of implementing and using Inventor. What gets by for using AutoCAD will seldom work for the demands of 3D modeling in Inventor. •u Set aside time for training and implementing Inventor. If you have multiple users, it might be best to consider phasing Inventor in over a period of time, allowing new users to acclimate themselves to a new way of design.
| Chapter 1 Inventor Design Philosophy Fewer Physical Prototypes Although you may never be able to go straight from Inventor to your first article design, you can use Inventor to reduce the number of physical prototypes needed to get there. More and more, creating physical prototype after physical prototype is becoming a part of “the old way” of doing things. It worked when you produced a small number of product units and had plenty of time and resources to lend to the project.
Understanding Functional Design Too Busy Getting Drawings to the Shop to Build Virtual Prototypes? You have deadlines to meet, you’re trying to learn a new design tool (Inventor), and you are being told to spend more time building models? Deciding when to build a virtual prototype depends on your business and the complexity of the design. At some point, everyone has probably given rough sketches to the shop to get a part made, but no one wants to do that on a regular basis.
| Chapter 1 Inventor Design Philosophy Functional design supports design through generators and wizards that add mechanical content and intelligence. By using the components within Inventor functional design, you can create mechanically correct components automatically by entering simple or complex mechanical attributes inside the generator.
The Bottom Line | The Frame Generator The Frame Generator will create internal or external frame assemblies for machines. The Frame Generator functions by creating a skeleton part to define the frame within an assembly file. You use the skeleton to place and size the frame members. You can then use multiple skeletal models within an assembly to create frame members, and you can create frame members between skeletal models.
| Chapter 1 Inventor Design Philosophy Get the “feel” of Inventor. Inventor’s interface contains many elements that change and update to give you the tools you need to perform the task at hand. Getting comfortable with these automatic changes and learning to anticipate them will help you get the “feel” of Inventor. Master It You create an extrude feature using the Extrude button, but you cannot seem to find an Edit Extrude button.
