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MecSoft's VisualMILL and VisualCAD Software for Computer-Aided Machining

By John Callen, February 1, 2013

VisualMILL 2012 from MecSoft Corporation is a CAM (computer-aided manufacturing) product with 2½-, 3-, 4- and 5-axis milling capability. It is suitable for general machining, as well as specialized areas such as rapid prototyping, wood working, mold, and tool and die applications. VisualMILL comes in four configurations - Standard, Expert, Professional and Premium - with functionality seamlessly building on the base configurations up to the most complex:

FreeMill is free, as in $0. This review focuses on VisualMILL's Standard configuration.

User Interface

VisualMILL’s interface is an expansive combination of pull-down menus, tool bars with graphical icons (with helpful tooltips) for viewing and standard operations, a tabbed command bar with collections of geometry operations, and a status tool bar with read-outs (see figure 1). At first, the interface seemed overwhelming to me, but then I found that its organization consciously arranges access to functions in a way that makes sense with greater familiarity with it. In addition, the user interface is fully configurable, so it is very easy to reorganize it as desired.

Figure 1: The user interface of VisualMILL

There are three major working areas within VisualMILL: the graphics view, which displays the part and process; the Machining Operations browser, which manages the machining job’s context (machine tool, post and stock) along with the setups and corresponding operations; and the Machining Objects browser, which manages the machining resources (tools, regions and knowledge bases). As elements of the machining job are defined, they are added to the various browser graphs.

VisualMILL’s workflow is full of opportunities to specify all sorts of intricate machining details. On a higher level, it is relatively straight forward to follow and the interface is laid out to reflect the sequence. Starting with the Machining Operations Brower in the Program tab, aspects of the machining job are defined. At any point along the way, the machining processes that have been defined can be simulated and validated.

Part Geometry Creation with VisualCAD

VisualCAD is a free CAD application from MecSoft that provides the foundation for VisualMILL. It provides machinists with extensive modeling capability to create part geometry, and to perform tasks like fixturing, avoidance areas, or to repair imported part geometry - without needing another, expensive MCAD program. The modeling capability is fairly extensive and does a good job of addressing these different scenarios (see figure 2).

Figure 2: The user interface of VisualCAD

NLib, a comprehensive NURBS library, was used by MecSoft as the basis for VisualCAD’s modeling capability. Though primarily a surface-based modeling system, VisualCAD also supports importing and maintaining solid models, as well as creating mesh objects - its own version of solids.

Though parts could be modeled using VisualCAD, it is expected that most parts will be imported into VisualMILL from other MCAD programs. In addition to its own proprietary formats, VisualMILL has the ability to import DXF, DWG, IGES, STEP, STL, VRML, RAW triangle, Rhino, ACIS, and Parasolid file formats allowing data to be transferred from every popular design system.

Machine Tool and Stock Setup

A key aspect of any machining job is the machine tool on which the work is going to be machined. VisualMILL provides a fairly straight forward way to define a machine tool by characterizing its operating parameters. The machine tool’s number of axes determines the definition parameters that are used. Simple machine tool definitions are specified by the tool change location and the minimum and maximum travel limits, which the machine tool’s work envelope. Machine tool definitions can be saved to file and then reloaded into the system.

Once read into VisualMILL, the part geometry is then oriented and a stock volume is defined. Defining stock is fairly simple: a bounding box is computed by the system or copied from the model and then its dimensions can be adjusted as desired. The stock is then positioned relative to the part geometry by separately specifying the Z and XY alignments.

Tooling and Machining Parameters and Operations

VisualMILL provides a fairly conventional means to define a variety of tooling. Once a tool is defined, the user has the option to manually set the feeds and speeds used with the tool or can apply values retrieved from VisualMILL’s material library, which contains 46 common types of material. Tools can be defined prior to creating the machining process, or they can be defined while creating the machining process, or tooling sets that had been previously saved can be read into the session setting up a default context. Users will greatly benefit from setting up standardized tooling with shop proven feeds and speeds. This approach provides for consistency and minimizes programming errors.

VisualMILL Standard comes with a collection of 2-, 3-axis and hole making operations. The 2-axis operations cover facing, profiling, pocketing (with avoidance areas), hole pocketing, V-carving (roughing and finish), engraving, thread milling, and chamfering. The 3-axis operations cover horizontal roughing, horizontal and parallel finishing, radial and spiral machining. The hole making operations cover drilling, tapping, boring, and reverse boring. These operations represent a common set of basic machining processes.

The interface to defining operations is a tabbed dialog; each aspect of the operation such as machining features/regions, tool, feeds & speeds, clearance plane, cut parameters, etc has its own tabbed context (see figure 3). An operation is completely defined by visiting each of these contexts and setting the corresponding parameters. Specifying every aspect of an operation can be fairly involved, but the tabbed contexts break it down into manageable chunks. There are also descriptive graphics where appropriate to explain the context.

Figure 3: Operations are defined by dialog boxes like this one for 2½ axis profiling

After all the operation’s parameters have been defined, the tool path can be generated. Tool path generation seems to be relatively fast, even for complex part geometries.

The machining operations can be archived to a knowledge base, which can then be used with other family of parts.

Simulation, Job and Shop Documentation

The Standard configuration of VisualMILL includes a capability to simulate machining processes. This is a conventional material removal simulation, which allows the job to be visually validated to ensure that all features are machined, that the tool does not rapid through the stock, and that excessive material is not removed. There is standard video player control (play, step, step levels, to end, pause stop) to control the simulation. Process simulation is expected functionality in CAM systems today and VisualMILL’s simulation capability does an adequate job of validating the machining process.

Once the NC program has been created, VisualMILL can generate corresponding shop floor documentation for reference (see figure 4). The Machining Operations Information report is a short form table that contains all of the operations’ tooling, feed rate, number of GOTOs, and elapsed machine time and is very useful for providing insights into the machining job. VIsualMILL can also create a Setup Sheet for the job in HTML format, which contains a summary of the job, a view of the part relative to the stock used, the list of tooling used in the job, and the operations list. The documentation produced is relatively basic, but informative none the less.

Figure 4: Shop floor documentation generated by VisualMILL

Post Processing

In addition to the dozens of posts which ship with VisualMILL, there are 161 posts templates which can be downloaded from MecSoft’s Web site. These posts represent a broad set of commonly used machine tools. Posting is simply a matter of selecting which operations to output and the output file.

A post editor tool is supplied allowing existing posts to be modified or new posts to be created. The editor provides a simplistic table-based means to define different aspects of NC code output. Editing a post processor is not something recommended for a novice user as it requires considerable knowledge about programming your machine tool and directly affects the reliability and quality of NC code generated.

Summary

Like most other CAM systems, users should have some level of machining expertise in order to be proficient with VisualMILL. That is not to say that a non-machinist novice would be unable to use VisualMILL, just that VisualMILL is designed more for the machinist. The terminology and parameters used in the system are very specific to machining, so real shop floor experience is useful in understanding them in context.

A powerful aspect of VisualMILL is its ability to create standardized definitions of manufacturing resources (machine tools and tooling) and processes. These are a real benefit to users and an investment that will pay for itself many times over. Using standardized definitions allows novice users to leverage the collective knowledge. The file-based nature of these standardized definitions requires the user to introduce their own storage scheme; a storage system and means of controlled access would be a big improvement to this feature’s usability.

The VisualMILL product family is an extremely capable application series which offers the user a broad range of scalable functionality. For general purpose 2.5- to 3-axis milling, VisualMILL Standard provides a comprehensive suite of functionality that most users would find rich enough a starting point to address their NC programming needs.

Starting off with the Standard configuration, users can learn how to use the application and then graduate to more advanced functionality by adopting the more advanced configurations when need be.

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Additional Information

http://www.mecsoft.com/visualmill2012.shtml

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About the Author

John Callen has been in CAD/CAM for over 30 years, recently as product manager with Autodesk. Previous to this, he worked for Gibbs and Associates and CAMAX. More...

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