High marks for a software standard

Tooling & Production, Jun 2001 by Christman, Alan

T&p softwaresolutions & NC machine controls

CIMdata rates Mastercam

CIMdata views Mastercam as the de facto industry standard PC-based CAM software product. It is a well-known, competitively priced general-purpose product that provides a broad base of modeling and NC software capability. It is appropriate for most machining environments, from production machining operations within manufacturing firms to machining relatively complex surfaces within mold shops. It is particularly well suited to job shops that have a wide range of machining requirements.

Version 8-with full associativity, a new Operations Manager and support for high-speed machining-is a significant enhancement to Mastercam. It raises the product's functionality to a new level.

By way of explanation, a model is associative with dimensions, so that as a model changes, the dimensions are automatically updated. Also, a model is associative with a toolpath, so that as a model or machining parameters change, the toolpaths are automatically updated. Being fully associative adds significantly to the software's usability.

CNC Software does not target any specific application area. Instead, it provides an extensive range of tools that cover a broad segment of the market. Mastercam includes capabilities for manufacturing modeling, 2- to 5-axis milling, 2- to 4-axis turning, mill-turning, holemaking, wire EDM, sheetmetal operations, post processing, and toolpath verification. The bulk of the standard products are internally developed, which is unusual for a firm of its size. Mastercam includes a competitive manufacturing modeling capability. Mastercam Design is the standard and most commonly used modeling product offered by CNC Software. It includes functionality for wireframe and surface model creation, geometry editing, surface blending, geometry analysis, drafting, and file management. It is a NURBS-based system. Third-degree curves are generated, but 21st degree curves are maintained. A tolerance can be specified when creating a surface or blending surfaces together. A line of intersection between two surfaces can be computed. Some of the surface modeling and blending capabilities in Mastercam Design include creation of:

* Parametric and NURBS surfaces using loft, ruled, revolved, swept, draft and offset creation methods.

* Swept surfaces with an unlimited number of cross-sections.

* Constant and variable radius fillets.

* Blended surfaces such as a ball corner blend. However, with a single command, a blend is restricted to three surfaces.

* 3D primitives of surfaced blocks, spheres, cylinders, cones and other shapes.

* NC Advanced Machining, which includes mill-turn and 5-axis milling.

Solid modeling is not included in basic Mastercam Design. Instead, CNC

Software has met the industry requirement for solid modeling with the introduction of Mastercam Solids as an add-on module that is integrated within Mastercam Design. When employed, it provides an integrated wireframe, surface and solid modeling capability. From a menu pick, a user can create a model in any format. The hybrid modeling techniques can be interspersed. Wireframe or surface elements can be added to a solid model, or solid components can be added to a surface model. The wire-- frame, surface, and solid geometry all reside in the same database. Most modeling is done with surfaces or solids, but a wireframe is often used to define a billet to be used as stock material.

Mastercam Solids utilizes the Parasolid solid modeling kernel. The solid modeling functions available are what would be expected from a Parasolid-based system. They include Boolean addition, subtraction, and common volume calculation between solids; shelling and thin-wall creation; extrusion, loft and sweep commands; drafted solid faces; and volume, surface area, and center-of-gravity calculations. Parasolid files can be imported as true solids, surfaces and/or wireframe models to Mastercam Solids. Parasolid files can also be exported.

CIMdata is favorably impressed by the modeling approach taken by CNC. It maintains Mastercam Design as the commonly used standard product. At the same time, it adds an integrated wireframe, surface and solid modeling module. It should meet the needs of the customers.

CNC Software does not currently offer a standard Mastercam product specifically developed to design mold bases, including cores and cavities. This is a relatively serious weakness in the current product set, since CNC Software is targeting the mold market. Dedicated products to automate the mold design process are becoming increasingly important to moldmakers.

However, Mastercam Design does satisfy some of these needs. Moreover, CNC reference sells Moldplus, a third-- party product developed by one of the Mastercam dealers for core and cavity design. It was developed in C and has been integrated into Mastercam using C-hooks technology. However, Moldplus appears to be a competitive product. It is used extensively by Mastercam moldmaking customers. Moldplus provides the standard functions often available in software employed for design of cores and cavities.