Figure 5: Adding 3D Features to a 2D Sketch – Extrusion with Several Types of Features Applied

Applying Dimensions

At the 2D level, there are several dimensioning modes available, including

• Normal – dimensions point to point
• Baseline – dimensions from the first point selected to successive points
• Continuous – dimensions continuously between successive points
• Ordinate – similar top Baseline, but each successive point receives an ordinate value measured from the first point.

For 3D, with ZW3D’s dynamic dimensions you can pick and drag 3D dimensions for modifying shapes with simultaneous visual feedback. This ability lets you construct 3D geometry with parametric dimensions because they are automatically created during the design process.

 

Applying Constraints

If required, and they usually are, constraints can be applied in both 2D and 3D design environments.

In 2D, there are several commands available for adding constraints to an active sketch, such as anchor, parallel, perpendicular, co-tangent, etc. Like it or not, constraints force conditions on geometry as a sketch is modified. You can choose commands to analyze and solve the constraint system of a sketch. 2D constraints (and dimensions) can also be applied automatically to sketch geometry on the fly by using the Constraint toolbar and selecting a base point.

In 3D, the constraints are are most commonly applied are assembly alignment constraints. For assemblies, inserting component parts and adding alignment constraints are considered individual steps in parametric history. This is a good feature because constraints can be added in any order since they are not bundled with components or replayed sequentially during a history replay. When a 3D constraint is applied, a short animation shows the parts aligning and moving into place in the assembly. Alignment constraints can be added, deleted, solved, edited, dragged, and investigated. Alignment constraints can also be applied to anchor components in a fixed position. Applying 3D constraints can be time consuming, however, because in most cases, multiple constraints are required to properly align a component.

 

Two Modeling Approaches – Parametric and Direct

Before we go any further, you should know that ZW3D provides two different modeling methods – history-based and direct. History-based modeling employs a History Manager, or what other parametric system vendors call a history/feature tree.

ZW3D’ SmoothFlow Direct Editing combines the best of both worlds – the speed and flexibility of direct modeling with the precision of dimension-driven modeling, while still maintaining the functionality of history-based modeling. Using SmoothFlow, you can directly modify model geometry without generating editing history – a real time saver, since creating and editing history-based geometry can be a challenge.

QuickEdit is a new ZW3D technique that streamlines creating and editing shapes. With QuickEdit you don’t have to pre-select an editing tool. Instead, you touch a part’s face or edge, right click the mouse, and choose a tool, such as fillet, offset, or move.

SnapPick is a new ZW3D option that takes a point pick and automatically drives it from intersections, critical, points, and axis directions. You can think of SnapPick as an assistant for helping create 3D sketches, features, and parts.

The direct modeling/editing approach provided by ZW3D is unique because of the way it employs a feature tree. While some competitors have abandoned the feature tree with their direct approaches, it does make for a workflow that is easier to track and understand. Direct model editing lets you pick directly on geometry for quick modifications. You also have different options for viewing how the model was created with the ability to display the history of modeling operations, a list of parent and/or child operations, as well as the ability to replay and step through a model’s history.

Important for ZW3D users who are involved with both CAD and CAM, regardless of whether you model parametrically or directly, any changes made to geometry automatically updates associated CNC program output downstream.

 

Stepping Up to Assemblies

Creating assemblies from parts in ZW3D Premium 2011 is one of its strengths because assembly modeling is key to ZW3D’s underlying design philosophy. It supports efficient assembly definition, manipulation, and management, and was a fundamental consideration when the ZW3D architecture was conceived and designed. For example, ZW3D’s Object Manager loads only display data for an object into memory if unless that object is active for edit, minimizing an assembly’s memory footprint while maximizing the size of an assembly that can be worked with. The Object Manager also lets you decide how assemblies are distributed into files – ranging from each component in a separate file, an entire assembly in one file, or anything in between.



Figure 6: Toggle Clamp Assembly With Alignment Constraints Applied

ZW3D Premium supports the two main assembly creation approaches – bottom-up and top-down.

In bottom-up assembly design, assemblies are broken down into smaller subassemblies and components, and each component is designed as a separate, unique part. The component parts can be archived in a library in one or more ZW3D files, making this approach an efficient way for creating and managing large, complex assemblies. Each part is inserted into the active part, creating a component instance and an assembly. The component becomes the child of the active part and then it becomes the active part. Because an instance of an actual part is used, you can have it update automatically if the archived part is modified, or you can modify the archived part by activating and modifying its component instance. While it might sound complicated, it really isn’t, and this ability illustrates the flexibility of ZW3D.

In top-down assembly design, all components are typically designed and placed while you are in an active part. Using the top-down method in ZW3D, the active part actually becomes the assembly. The component becomes a child of the active part and then it becomes the active part. When created, the component is an instance of an original part that becomes a root object placed in the active file. The part or each component is activated and can be edited. The top-down approach is generally considered more advantageous than bottom-up. Why? Here’s a typical example. If you are working on a new design, you can elect to keep all component parts in a single file until the design project nears completion. If the project is cancelled or you decide to go in a totally new direction, deleing the one file deletes the part or assembly and all of its components.

The PartSolutions library, at no additional cost, makes standard parts from a wide variety of suppliers available for insertion into an assembly. At the part level, with the PartSolutions PartAssembly application, you can insert components in to active ZW3D assemblies. You select the part group that you want, such as fasteners; select the specific part you want to insert and modify it if you need to; click on the Transfer to CAD icon; and in ZW3D, select the insertion point for the new component.



Figure 7: The PartSolutions Library

Finally, ZW3D supports its proprietary lightweight Burst technology that lets you manipulate large assemblies without memory constraints. The tree structure for assemblies allows individual component parts to be graphically highlighted for identification and modification purposes.

 

Creating Drawings

ZW3D automatically creates 2D associative detail drawings directly from 3D models from which they are created, so the process is pretty streamlined. The production drawing and detailing process are assisted by ZW3D’s unique object server architecture that lets you decide whether drawings will be saved in the same file as the 3D data from the master model or in separate files.

Drawings provide an opportunity to briefly discuss ZW3D’s architecture that is a multi-level object-oriented system with access to its various integrated modules (such as drawings, CAM, etc.) through a common user interface. Rather than having to launch separate applications for drafting or CAM, you just open a ZW3D file and proceed to the level you want; in this instance the Drawing Level for creating and editing drawing packets and drawing sheets. The Drawing Packet Level contains functions that are used to create drawing packets, while the Drawing Sheet Level is used to create drawing sheets. In ZW3D, a drawing packet is a collection of one or more drawing sheets. A drawing sheet is where model geometry is located.



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-- Jeff Rowe, MCADCafe.com Contributing Editor.