Real Knowledge Behind KBM

By Ann Mazakas

There’s been a lot of buzz about knowledge-based machining (KBM) in the CAM industry over the past few years, with many CAM systems claiming KBM capabilities. Take a closer look and you find that the term KBM is often used loosely in the CAM industry to describe a system that simply stores past machining operations for future use. To take advantage of this system, a user must still remember the correct template or process to apply in a given situation.

The true power of real KBM comes from a database that stores information about the actual conditions on the shop floor and then intelligently applies that knowledge when a new part needs to be machined. In such a case, the KBM system automatically selects the most appropriate tools and machining strategies based on information about the part, calculates feeds and speeds, and automatically generates the NC code.

Vero International (Wixom, MI) gets KBM right with its latest release of machining STRATEGIST v8.0, which includes a new KBM database that is intelligent in both design and capabilities.

For version 8.0, the previous tool library in machining STRATEGIST underwent a complete redesign. The new library, now aptly named the Technology Library, does much more than store information about tools and holders.

machining STRATEGIST

> > Cutting tools are quickly defined by tool material and tool type. The tree structure does double-duty as a convenient filtering tool to display tools by material or type.

The new Technology Library underpins all operations within machining STRATEGIST with data that is accessed automatically when a project is created. At project startup, the user specifies the default technology library, the machine tool, and the part material for the project.

For all the power that is built into the Technology Library, it is remarkably easy to use. The Technology Library Editor takes the user through the process of setting up cutting tools and cutting conditions, tool suitability, tool holders, plan parameters, and general cutting conditions.

Setting up machining data has never been easier. The interface uses a familiar tree structure to the left of the screen and a main window to the right where details are entered. Entering data is as easy as selecting an item in a tree, such as a tool type or machining operation, then right-clicking in the main window to add data about the selected item. Navigating from cutting tool to feed-and-speed data is as simple as clicking the toolbar icons across the top of the screen.

The Technology Library lets users set up any number of libraries about conditions on the shop floor, such as machine tools and materials, and preferred machining parameters, such as feed rates and spindle speeds. For a job shop, this is a great way to set up custom libraries for different customers.

Tool suitability is a unique feature of the Technology Library. All CAM systems provide a way to define the physical characteristics of cutting tools, such as diameter, tool length, number of flutes, and whether they are metric or sized in inches. Some systems also provide a way to group tools by selected criteria such as sizing parameters, high-speed, milling, by vendor, and so on. While this is useful, the user must know what group to select for the specific machining situation.

machining STRATEGIST

< < After a tool is defined, its suitability for particular jobs can be defined by multiple combinations of part material, machine tool, and type of cut. When a project is created, only those tools suitable for that project will be available for selection.

machining STRATEGIST v8.0 goes one step further by providing a means of describing the suitability of a tool in a given situation. The user can allow or restrict the use of a tool for different materials, machine tools, and cutting modes (rough, semi-finish, finish). When a machining operation is created in machining STRATEGIST, only those tools suitable for the selected part material, machine tool, and cutting mode are available for selection.

By defining the tool’s suitability, machine tools and material can be assigned to more than one tool while still allowing the system the flexibility to recommend the speeds and feeds defined in the general cutting conditions.

machining STRATEGIST v8.0 offers two new ways to automatically enter parameters in machining operations: for all operations through Plan Parameters or for operations within a specific project through Project Variables.

machining STRATEGIST

> > Plan parameters can be defined for virtually any machining situation. In this example, the plan parameter specifies that a 10mm solid carbide cutter will be assigned to tool number 2 when a Mori Seiki machine is used. The same tool can be assigned different numbers based on the machine used.

Plan Parameters are defined in the Technology Library and let the user define system parameters through the use of formulas. For example, the user can specify the tool step over or step down for a particular operation based on a percentage of the tool diameter. For total customization, Plan Parameters can be defined to an even greater level of granularity based on the tool, part material, and machine tool. For example, the user can define different formulas for the step over when different types of material or different machine tools are used.

Project Variables are defined by the user within a project and apply to all operations created within that project. For example, if the user wants to use the same spark gap allowance for all machining operations, this can be set up as a variable. The variable is defined once and then used whenever needed. Another advantage is that updating the variable will automatically update all related operations.

machining STRATEGIST

< < Spindle speeds and tool feed rates are quickly defined by simply selecting the part material, tool material, machine tool, and type of cut.

Plan Parameters and Project Variables both use formulas that allow the entry of parameter names from operations such as ToolCutterDiameter or ToolFluteLength. In this release, parameter names can be obtained by opening the desired operation in machiningSTRATEGIST, copying the parameter name from the dialog and then pasting the name into the formula.  (In the next release of machiningSTRATEGIST, programmers might consider offering a list of parameter names for users to choose from when creating a formula.)

As with other CAM systems, machining STRATEGIST will save a set of machining operations as a process that can later be applied to similar parts. Unlike other systems, the machining parameters within the process are updated automatically based on the selected technology library, machine tool, and part material whenever the process is applied to a new part. For example, if the step-down parameter in the Technology Library is set to one-fourth the tool diameter for aluminum and one-sixth the tool diameter for carbon steel, the process will use the correct step down based on the current material specified.

machining STRATEGIST

> > Formulas can be used to define a plan parameter. In this case, the amount of step down for an Area Clearance roughing operation is set to 30% of the tool diameter. No matter what size tool is used, the step down will always be 30% of the diameter whenever graphite is being cut.

Quite often, technologically powerful software is difficult to use. machining STRATEGIST v8.0 puts all the power under the hood with a sleek design that invites the user to jump in and get rolling. The programming and data management are taken care of behind the scenes, letting the user focus on getting the job done in a familiar and friendly environment that is a snap to learn. Vero International has designed an elegant knowledge base.

Ann Mazakas is the president of Intelligent Creations LLC, a provider of services to the manufacturing industry. With an extensive background in engineering and manufacturing, she has built an in-depth knowledge of the CAD/CAM software industry. Send your comments about this article through e-mail by clicking here. Please reference “machining STRATEGIST” in your message.

machining STRATEGIST v8.0
Vero International Software
Wixcom, MI