Parts manufacturers: can engineers and designers easily use your CAD files?

Are you a parts manufacturer? Do you provide your customers and prospects with CAD models for your products? If so, you are already on the right track! But are you really aware of the quality of the CAD files that you are generating?

Every year, the modeling experts at TraceParts analyze thousands of STEP files. Unfortunately, they have come to the realization that many manufacturers fail to adopt the right methods for modeling their parts and often run straight into a number of problems caused by surface entities.

Why should you offer CAD models without any surface entities?

As we will see a bit later in this article, design software programs struggle with CAD files when they contain surface entities. That explains why engineers and designers prefer working with solid-modeled parts.

We will see that there are three types of 3D modeling: wireframe, surface and solid.

These models offer an effective view of a product’s complexity. Users can examine the model from every angle and change the type of representation (shading, view of any hidden edges, etc.).

These modeling techniques satisfy the interests of both engineers and manufacturers, since an open model can be connected with specific software programs for the purpose of creating different applications or operations, such as calculating structures, developing route sheets for machining processes, and programming machine tools.

Wireframe modeling

This is the first level of 3D modeling and mainly draws its inspiration from 2D models, but adds a third dimension. Wireframe models are based on points and lines.

This type of technique can be used to model geometric shapes with a higher degree of complexity than 2D modeling, but it does not contain any surface or volume.

Surface modeling

As its name suggests, surface modeling takes account of the object’s surface and can be used to easily represent and manipulate the product. Surface modeling is often used for esthetic considerations and especially for consumer goods. The way in which the product will be used is less important.

This first level of modeling can deal with hidden parts using flat facets or curved surfaces:

• Flat facets: the model is represented by facets. A wireframe structure is dressed with flat polygonal facets. A large number of facets can be used to create a correct representation of the object.

• Curved surfaces: this method is used when the required surface is too complex to be defined with simple surfaces (planar, cylindrical, spherical and conical surfaces).

Solid modeling

This is the most extensive form of modeling, because it encompasses the two previous techniques (wireframe and surface modeling). It represents objects in space combined with material properties.

To create an object, 3D solid modeling:

• Uses primitives: these simple solids are stored in a library, where users can pick a solid to suit their needs.

• Assembles by constraints, which are conventional Boolean operators, such as union, intersection and difference. They can be used to combine primitives to create more complex solids.

• Manipulates solids with geometric operators, which are conventional geometric transformers. The main transformers include translation, rotation, symmetry and homothetic transformation.

This model improves knowledge of the notion of material. It provides an exact and unambiguous definition of the object, meaning that it is a favorite model among machine parts designers.

It simplifies the design process, since it can model complex arrangements and assemblies. It also simplifies design by supporting such notions as assembly, esthetics and feasibility.

In addition, it improves visualization of the object by determining the intersecting volumes and perspectives (external and internal). External perspectives provide information about the object’s apparent contour, outer appearance and dimensions. Internal perspectives offer information about the internal shapes, arrangements and mounting possibilities.

At the present time, new industrial parts suppliers are not immediately focusing their sights on solid modeling for their products and are instead opting for the surface modeling method.

However, although the aim is to provide engineers and designers with models of their products, surface entities will cause problems for the end user. Design professionals will lose time removing excessive or problematic surface entities in their CAD software, whereas if you start out by providing them with solid models, you will not run into this type of issue.

After reading this article, you might be wondering whether engineers and designers can easily use your CAD models and whether they contain surface entities?

It’s simple! Let TraceParts test your CAD models! We help industrial parts manufacturers analyze the quality of their CAD files and fix their surface entity problems, thereby making life even easier for designers and engineers.