Autodesk Mechanical Desktop Integrating Toolbodies into Your Design Flow

By Janet Peterson,2014-11-29 04:20
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Autodesk Mechanical Desktop Integrating Toolbodies into Your Design Flow

    Autodesk Mechanical Desktop: Integrating Toolbodies into Your Design Flow By Bill Fane

    Seems to me that the toolbodies capability in Mechanical Desktop? software has been overlooked by a lot of users and that's unfortunate; it's a powerful, easy-to-use function, as you'll soon see, that you can use to create models of molds, patterns, and other tooling directly from the model of the part you want the tooling to produce. You can also use toolbodies to create complex parts that would be difficult or impossible with normal modeling techniques. First, let's review the basics. Building a part in Mechanical Desktop is normally a sequential process. Once you create a part's basic shape ("the basefeature"), you begin adding other features. Each succeeding profile needs two additional dimensions or constraints to tie it to the existing part.

    When working in an assembly file, you can always start a new, independent part that subsequently assembled with and constrained to the other parts in the assembly.

    On the other hand, a new part file can only ever contain a single part and, therefore, all subsequent features must be directly constrained back to the existing partexcept when you use toolbodies.

     Figure 1: Create a drawing of the casting core first.

     Figure 2: To produce the core box, subtract the core (as a toolbody) from the block.

    Take a look at Figure 1, which shows a core (in magenta) to be used in the production of a sand casting. Of course it requires a core box, which is basically a mold into which you pack the special sand used to make the core. Figure 2 shows the core box in yellow.

     Figure 3: A gold brick is the base part, the red object is created as a toolbody.

    There are two ways to build the model of the core box.

    The first, most-often used way is to design the core and then subtract the core's five features (the magenta part), one at a time, to arrive at the core box. This obviously involves a duplication of effort and takes some messy work with parameter files to keep the model of the core box in step with any changes made to the model of the core. The other waythe toolbody wayis to design the core and then use it as a toolbody to create the core box. This requires just two features, and is automatically linked to the core model. Let's work through a simple example together, and then I'll show you a few more samples and give you a few tips.

    1. Open a new drawing file, and sketch a simple part, a rectangle. 2. Profile and dimension it. 3. Extrude it into a brick.

    You're now ready to create a toolbody.

    1. Use one of the following commands to start the operation. Not surprisingly, you have at least three ways to start. You can

     Type in amnew at the command prompt. From the main menu, double-click Toolbody and then click New Toolbody. Click on the hammer-and-wrench icon in the main toolbar. The Toolbody Modeling shortcut menu appears. Click the hammer-and-wrench icon again in the flyout. 2. Once the command has started, press Enter to accept the default name, <Toolbody1>, which appears after each of the above command sequences, or name it as you choose. 3. Press Enter.

    Nothing much seems to happen. Mechanical Desktop simply drops back to the command prompt. Closer inspection reveals that a Toolbody1_1 entry has appeared in the browser; right-clicking it indicates that it is active. You can now proceed as if you were working on a new, independent part.

     Figure 4: The toolbody is constrained to the base part using assembly constraints.

    Figure 3 shows the original gold brick and a new toolbody, in red. I built the toolbody by revolving a profile and then adding a rectangular extrusion to one end, as if I was building a new, independent part. Its profiles did not need to be constrained to the existing part.

    4. Build the toolbody in any way you choose.

    5. Suitably constrain the toolbody using 3D constraints. Once again, there are several ways to start this operation:

     From the menu bar, pick Toolbody then 3D Constraints.

     From the Toolbody Modeling toolbar pick 3D Toolbody Constraints, which is the little red c-clamp icon.