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Ch32-I044963.fm Page 153 Monday, August 7, 2006 11:28 AM
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DIRECT PREDICTION OF CUTTING ERROR IN FINISH
ENDMILLING BASED ON SEQUENCE-FREE ALGORITHM

1
1
2
J. Kaneko , K. Teramoto , K. Horio and Y. Takeuchi 2
' Department of Mechanical Engineering, Faculty of Engineering, Saitama University,
Saitama, Saitama, Sakura-ku, Shimo-Ohkubo, 255, Japan
2
Department of Computer Controlled Mechanical systems, Graduate School of Engineering,
Osaka University
Osaka, Suita, Yamadaoka, 2-1, Japan

ABSTRACT

This study deals with a new estimation method of cutting error distribution on workpiece surface,
which is caused by cutting force and tool deflection. The proposed procedure is based on
"sequence-free" algorithm of cutting force prediction, which makes it possible to predict directly
cutting error in an arbitrary tool position regardless of the order of tool movement in NC program. By
applying the proposed procedure, quick estimation of cutting error distribution is realized. As a result,
it is expected that NC operators can collect easily cutting conditions and cutter location in NC
program with consideration of cutting error.

KEYWORDS

End mill, Machining, Instantaneous Cutting Force, Prediction, Cutting error, Tool swept volume

INTRODUCTION
Today, verification process for NC program plays very important roles. Especially, estimation of
cutting error distribution on workpiece surface in finishing process is earnestly required. In
conventional studies, many verification methods have been proposed. They are designed to verify
geometric errors in NC program and already widely used. On the other hand, prediction of cutting
error caused by instantaneous cutting force and tool deflection is not yet put in to practical use.
As a reason the error prediction about tool deflection does not spread, we focus following problems.
• In order to predict instantaneous cutting force, accuracy of estimated cutting depth is needed.
• Estimation process of cutting depth requires accurate explicit information of workpiece shape.
• The workpiece shape is usually changed by each tool movement step and complicated.
Usually, each part of workpiece surface is generated at different moment in machining. These facts
mean that the prediction process for cutting error distribution caused by tool deflection requires vast
amount of geometric calculation to estimate the explicit workpiece shape information.