Research Notes

At the Center for Machine Tool Systems Research of the College of Engineering, University of Illinois at Urbana-Champaign, a program underway is called A Methodology for High Speed/High Performance End Milling. Due to short contact times between cutting-edge engagements and process errors, the dynamic behavior of machining at speeds 2-3 times higher than conventional speeds is not well understood. The objective of this project is to model the end milling dynamics in the presence of process faults such as parallel axis offset runout, spindle tilt, and gyroscopic and rotary inertial effects, and develop a methodology to evaluate a given machining application to determine an optimum process plan.

For more information, go to www.mie.uiuc.edu/content/asp/resear cb/research_projects/manufacturing _systems_l.asp.

At the Rapid Prototyping Laboratory of Stanford University (PaIo Alto, CA) Microengine production processes are being developed. Mesoscopic engines have attractive performance characteristics, and silicon nitride is considered a good candidate for small-turbine engine applications. Using the Mold SDM process under development at the laboratory, researchers can produce ceramic parts with high geometric complexity and superior surface quality. Parts made of silicon nitride using this process have achieved surface quality comparable to machined surfaces. Current research seeks to improve the process to achieve better dimensional accuracy, surface quality, and shape complexity.Product Decomposition is a project at the Robotics Institute of Carnegie Mellon University (Pittsburgh). During product development, designers often face the task of partitioning a product into functioning parts. Unfortunately, most decomposition decisions are based on product functionality and manufacturability, and consequently decomposed parts can be too expensive to manufacture and sometimes can't be made. In this project researchers present an approach to help designers decompose sheetmetal products that takes into account the manufacturability of cutting, bending, and assembly processes. It tries to minimize the number of parts. A develop-first, decompose-later strategy is used.

For more information, go to www.ri.cmu.edu/projects/project_299.html.

The OmniCNC project under way at the IMS-Mechatronics Laboratory of the University of California at Davis encompasses a number of ongoing research projects. One of them, Development of a Simulation System for Surface Roughness in Five-Axis Machining Process, seeks to develop a simulation system based on a Z-map model for predicting surface topographic features and roughness formed by five-axis CNC milling using a ball end mill. The model initially developed exhibited differences in surface roughness because vibration, tool deflection, built-up edge and other factors were not included in the simulation. To achieve improved results, factors such as tool vibration and deflection should be included in future simulation systems.