Parts such as ballscrew nuts not only require external thread whirling, but intricate internal threading as well. Internal helical threads on hardened parts are typically produced through multiple high speed grinding passes. As the length of the thread and/or thread helix angle increases, so does the difficulty in maintaining process stability and thread accuracy when grinding these internal profiles.
There’s a machine, however, that has an inverted vertical chucking design with a special oscillating tooling system that engages the part from below, offering an alternative to grinding internal helical threads. Because the Leistritz Innovation 200 internal whirling machine from Leistritz Corp.
provides inverted vertical chucking, it serves as its own part loading system.
During internal whirling, both the workpiece and single-point whirling tool rotate in the same C-axis direction. Machining is performed without coolant, and only one cutting pass is required to produce a finished internal thread.