Lightweight Tooling for Concentric Collet Drilling Templates

Abstract

This paper aims to meet clear business demand for lighter operational jigs and tools by reducing the overall weight of the concentric collet drilling templates using alternative lightweight materials and topology optimization techniques. The template structure was optimized by numerical modelling to reduce the mass and maintain relative strength. A cycle test that simulates the actual working conditions of the templates was conducted to understand the deformation and wearing during and after their usage. The simulation results indicate the challenges between reducing the mass and maintaining the stiffness of the drilling template. The hole size in each alternative aluminum template increased after 10,000 testing cycles; For harder materials like Al7075, the hardness of the borehole increased due to its high strength, to resist extending force from the collet. Whereas, for the materials with lower hardness like Al5083, the borehole hardness reduced after the cycle tests due to its low strength. The borehole surface roughness in the template increased due to wear caused by the horizontal pressure and vertical contact with the collet, which would severely increase the friction and reduce the lifetime of the template.