Processes for Fabrication and Optimization of a 90° Tool Holder for Large-Caliber Sabot Machining

Author(s):

Thomas King, Richard Labhart, Steven I. Dollenger, Gregory Weaver, Richard Weber, David Hall, Micah Gallagher, and Marshal Childers

Abstract:

This technical note is a case study of how ARL’s Experimental Fabrication Branch (EFB) collaborated with the Lethal Mechanisms Branch (LMB) to achieve program objectives for the Decisive Lethality mission program and improve processes and capabilities within the EFB Precision Machine Shop for future fabrication solutions. It details the process of engagement with EFB and the development effort to address manufacturability for realizing LMB designs. The procedures executed by the EFB Machine Shop for manufacturing, modification, and optimization for developing a custom 90° tool holder are presented. This tooling package supports LMB in reducing machining times for cutting grooves in large-caliber sabots. This technical note outlines the fabrication of the three-part 7075-T6 aluminum assembly comprising a quill–spindle–tooling profile, top clamp, and bottom clamp using computer numerical control (CNC) turning, CNC milling, and precision electrical discharge machining (EDM). It also chronicles four work packages completed under the project from May to August 2026, including the EDM bore enlargement of a legacy holder and tungsten carbide disc profiling. Finally, production bottlenecks are analyzed; and standardized guidance is provided to streamline setups, manage chips, and accelerate turnarounds for subsequent tooling runs.