End-Mill Milling Highlights Five-Axis Capability

Machining worn end mills on the show floor might seem like a promotion fit for a tool grinding company, but Kern Precision does not specialize in tool grinders. Rather, its focus is high-precision five-axis machines like the company’s Micro HD, which cuts materials that might otherwise be deemed ill-suited for machining – namely, sintered carbide and ceramics. To prove the point, the company invites visitors to bring in their own tools to use as “workpieces” for a contour-cutting demo.

A tool from 6C, which uses laser ablation to increase flute count and achieve sharper edges, drills into tungsten carbide on Kern’s Micro HD five-axis machining center. This machine is also useful for milling, drilling and thread-milling sintered glass and ceramic. Photo Credit: Kern Precision

Although this demonstration focuses on two relatively slim diameters – ¾” and 20-mm end mills – Kern’s ambitions for its new machine are anything but small. Linear motors and micro-gap hydrostatics (claimed to be a unique combination for a “true” five-axis machine), as well as fundamentals like thermal stability, dynamic acceleration and stick-slip-free motion, offer the possibility to replace other, more time-consuming processes.

One application where the Micro HD improves upon older, slower processes is the machining of punches for cutting inserts and medical tablets that were once produced via EDM. Another is cutting threads to an accuracy of less than 1 um in relatively brittle, 40%-silicon aluminum alloy for space telescope components.