Sabot Concept Evaluation Using Subscale Airgun-Launched 3-D Printed Components

A recent gun launch experimental program required that the pusher assembly of the launch package be diverted so that it would not follow behind the projectile being evaluated. Initial experiments showed that a subscale launch package fired from a 2-inch (51-mm)-diameter air gun exhibited similar sabot discard performance to the full-size projectile. The subscale launch package was assembled from parts built from plastic via rapid prototyping (3-dimensional printing). Subsequent evaluation of several sabot concepts revealed that the best design had one of the 4 sabot petals firmly attached to the pusher assembly so that the discarding sabot petal pulled the pusher assembly off of the line of fire. The modified assembly was fabricated and fired from the full-scale 8-inch (203-mm) gun. Sabot discard and pusher diversion occurred as expected, allowing the experimental program to proceed. The launch package modifications are described, and a simple analysis of basic equations of force and motion illustrates why a low-speed, subscale simulation can be used for first order evaluations of sabot discard phenomena.
The original document contains color images.