ESPRIT 2009 Complex 5-axis Milling

The appeal of multiaxis machine tools is obvious to machine shops of all sizes. These machines typically require only one setup to machine an entire part, saving time and improving accuracy between operations. These advanced machines also have the capability to change the tool axis direction in order to reach machinable areas with shorter, more rigid tools or to reach zones that could not be cut at all with standard methods (undercuts). These benefits make it easy to justify the cost of upgrading to the latest technology.

Usually this type of machine tool has two additional rotary axes incorporated either in the table that supports the part to be machined or on the tool head itself. The challenge is to generate CNC programs that fully exploit these additional axes in an efficient manner. In recent years, the growing complexity of this simultaneous machine movement has made this difficult because of both mathematical and technological challenges.

In addition, any software product designed for multiaxis machines must be easy-to-use and error-proof. The smallest programming error can generate costly damages because the materials, high-precision tools, and accessories for these advanced machine tools are quite expensive.

An Elegant Solution
Based on these premises, the challenge for CAM software developers is how to combine a set of powerful programming functions with a programming process that is easily understood by the user. The capabilities of these functions must be presented clearly, stepping the user through the programming process in order to avoid errors during toolpath definition, while never becoming rigid or imposing limitations.

Five machining patterns are available that range from a standard offset of the boundary to parametric patterns that use the flow lines of a surface as well as patterns created by intersection of the part and a set of user-defined planes that can follow a linear or curved path.

The latest release of ESPRIT, a high-performance computer-aided manufacturing (CAM) system, introduces a new concept in highly advanced machining functionality based on the idea that any five-axis machining function, no matter how complex, can be defined with a few simple steps.

This patent-pending technology in ESPRIT 2009 eliminates a problem commonly found in CAM systems, which is the conflict between powerful functionality and the ease with which it can be used.

In the past, CAM software developers resolved this conflict by fragmenting their product into various dedicated functions for very specific types of toolpaths in order to keep a reasonable number of options. A point of pride for some CAM systems is the large number of functions available. The price often paid for this type of software development is that soon the system becomes a labyrinth of functions with the typical end user knowing and exploiting only a limited number of them. Busy CNC programmers cannot possibly be expected to memorize the purpose of dozens of functions in a CAM system. Programmers typically stick to the functions they know best and ignore the rest.

Instead of fragmenting the advanced five-axis functionality added to ESPRIT 2009, the new 5-Axis Composite Milling cycle follows the same logic that machinists themselves use when deciding how to machine a complex five-axis part. Users are presented with a programming process that is familiar and easy to understand, not an overwhelming array of options that may or may not apply to the current machining situation.

By simplifying the methodology of multiaxis machining into one unique function, the user quickly becomes adept at exploiting the full power of the product. With this new approach to CAM functionality, maximum flexibility and compactness can be achieved in the field of five-axis machining definitions.

Four tool-orientation strategies give the user complete control over the orientation of the tool in relation to the part. Here, the tool is forced to pass through a selected point and is limited in its angle rotation to match the limits of the head rotation on the machine.

One Composite Function = Multiple Ways to Machine
The 5-Axis Composite Milling function is unique in that it separates the desired shape of the tool path on the area to be machined from the rules that govern the orientation of the tool axis during machining.

The Composite function is based on the idea that every milling job, no matter how complex, can be simplified into four well-defined steps:

• Define the area to be machined
• Define the shape of the tool path on the area to be machined
• Decide how the tool will be oriented as it follows the tool path
• Specify how the tool should move at the beginning, end, and in between cuts.

 

 

 

 

In this way, the user can create his or her own customized toolpath as a combination of available choices. In other words, by choosing from the five available machining patterns and the four different tool orientation strategies, the user has 20 different ways to machine the part. Add to that the ability to lock an axis and a five-axis tool path is quickly converted to a four-axis application.

The interface is simplified by only displaying options that apply to the current work situation. For example, if a parametric machining pattern is chosen, the user is prompted to select the drive surface and the parametric flow directions the tool should follow. If the user decides to change to a simple boundary offset pattern the interface updates to display fewer options.

As the user chooses machining options, the interface updates to guide the user in a logical manner through the programming process. This step-by-step guidance helps the user avoid errors in the toolpath definition without imposing limitations. If the user decides to change a previous option, the system responds by displaying a new set of choices.

The new 5-Axis Composite Milling function from DP Technology takes full advantage of simultaneous machine movement in a streamlined format that combines power with ease-of-use.

3D Features
In addition to the compact and simplified Composite cycle, ESPRIT 2009 has also simplified the way users select areas to be machined. A new type of freeform feature lets the user select and save the surfaces to be machined and the surfaces to be avoided as a single object. Knowing that different types of surfaces require different machining strategies, any number of these freeform features can be created on a single part model. The user can then select a single feature to machine an entire pre-defined area.

The design concept of consistency and ease-of-use is extended so that the same interface is used for the freeform features, the Composite cycle, the tool manager, and the operation manager in a tabbed layout. The user stays in a familiar environment without the need to open and exit multiple dialog boxes.

Adaptable for the Future
From the viewpoint of the software developer, the Composite function requires an in-depth analysis of each step used in the process of generating multiaxis toolpaths. It also requires real-world experience working with the types of multiaxis machines that are used every day on the shop floor plus the new technology being developed by machine tool builders.

This in-depth analysis has led to the Composite cycle being composed of a collection of separate components that perform well separately and together. These components are analyzed and tested to guarantee the complete interchangeability of any component at any step. This analysis effort lends itself to a high rate of reliability in the resulting software, which ultimately benefits the user. Efficiency is also achieved because each component is created only once, eliminating the redundancy that occurs when advanced functionality is broken into a slew of machining functions.

The advantage to this type of functionality is that new machining patterns and tool orientation strategies can be added to the software at any time in the future as the technology for multiaxis machines advances. The new 5-Axis Composite Milling function from DP Technology marks a departure from traditional CAM software development so that ESPRIT can easily keep pace with the rapidly evolving technology on the shop floor.