Enhanced Indexable Drilling

Throughout the last decade, the cost of raw materials for tungsten carbide has increased by more than six times, causing the cost of solid carbide tooling to significantly increase. Within the cost sensitive and increasingly competitive manufacturing industry, this rise in cost has caused a dramatic shift in the marketplace from solid carbide tooling to indexable and removable tip tooling.

As markets reduce the number of machining operations, more complicated indexable drilling geometries are becoming more common. In response to these changes and beginning with the hole-making tooling segment, Third Wave Systems, Inc. (TWS; Minneapolis, MN), a premier provider of validated material physics-based modeling solutions and services, redesigned the indexable drilling capability of AdvantEdge, their finite element analysis software that allows shops to better understand their processes, providing not only forces and chip shape results, but also stresses and temperatures throughout the cutting process.

Users can now import solid geometries from CAD software that include both cutting inserts and cutter bodies. Using the cutting parameters entered into the software, an in-cut workpiece is generated which allows the user to simulate the cutting process. “This ability to understand current capabilities and test new ideas in a virtual environment result in significant competitive advantages for shops in the indexable drilling marketplace,” explains Kerry Marusich, the president of Third Wave Systems.

This virtual simulation environment reduces, and sometimes even eliminates, the need for halting production during the prototyping process. The validated, material-specific modeling and physics-based machining calculations within AdvantEdge allow the knowledge-based design and comparison of new tooling. This indexable drilling capability includes a significant improvement to the automation of meshing parameters to calculate the parameters based directly on the in-cut chip thickness and incorporating interest overlap. This capability further automates the setup process for users, which allows for less setup time and more time spent analyzing results.

These features allow engineers to do both roughing and finishing operations with the same tool and can allow for the addition of a chamfer and improved chip control/higher material removal rate. Engineers who work with tool design have expressed an increasing interest in the modeling of indexable drilling applications to find solutions to many industry problems, including:

• Chip wrapping around the tool (which can cause tool overloading and part quality problems)
• Chip curl and evacuation from the hole
• Temperature generation and heat transfer on the workpiece and cutting edge
• Hole straightness and center location (tool deflection)
• The effect of various insert geometries on different locations on the same drill
• The impact of runout
• Cutter body loading and resulting deformation

To meet these needs and anticipating larger hole sizes created with indexable drills, AdvantEdge focuses on reducing rotating tooling simulation time by minimizing the effort put forth by the end user. The software reads all indexable drills in a single STEP file that contains all inserts (and optionally, the cutter body) to run the initial meshing and subsequent analysis that includes geometry and feed-based workpiece generation, chip load-based adaptive meshing parameters and support of both insert and tool holder modeling.

The software can automatically calculate radial and tangential per flute force output for an intuitive understanding of results as well as comparison of radial and tangential forces on each flute. It automatically predicts simulation time remaining based on current calculation speed, length of cut and length of cut remaining so that users can be more efficient in their decision making and effective with their use of AdvantEdge.

AdvantEdge 7.1 also includes first release verification document for users. Current verification done at TWS utilizes proprietary methods and customer data making it unsuitable for release. This document has been created using standard, non-proprietary, simple test cases and shows the comparison to analytical data in a form which is easily understood. Releases following version 7.1 will include these current tests and additional simple cases for user reference. Three stainless steel materials were added to this release, including M152, ASTM A182 Grade F55 and ASTM A705 Type 630.

Third Wave Systems, Inc., 6475 City W Parkway, Eden Prairie, MN 55344, 952-832-5515, www.thirdwavesys.com.