Protecting Against Tooling Pullout

One of the challenges of machining heat-resistant super alloys (HRSA) is overcoming end mill pullout under heavy torque loads. In response, Big Kaiser has designed the Mega Perfect Grip, an easy to use, heavy-duty milling chuck from Big Daishowa.

For manufacturers using milling chucks, pullout is a major issue, particularly when machining HRSA’s such as titanium or Inconel. In demanding applications involving the energy and aerospace markets, protecting against pullout avoids damaging costly parts or creating unnecessary delays in manufacturing processes, the company says. With fully concentric clamping, the milling chuck combines the accuracy and cutting performance of heavy-duty milling chucks with the security against pullout of solid side-lock toolholders.

The concept is simple and based around milling cutters with a standard Weldon flat (ASME B94.19-1997). No special grinding or threading of the milling cutter is required. Assembly is easy, involving inserting the exclusive key grip into the Weldon flat of the end mill. Align the key grip with one of three key grip grooves inside the chuck body, and insert the cutting tool until it depresses a spring in the clamping bore. The spring functions to remove the gap between the key grip and the wall of the groove, and to provide a slight axial preload on the tool until final tightening is performed. Rotate the end mill approximately 20 degrees until the grip stops securely against a stopping pin. This engagement prevents any slip under high torque. Finalize assembly by tightening the clamping nut until it contacts the positive stop of the chuck body. Three key grip grooves in the chuck body also serve to provide channels for high-volume coolant to reach the cutter, which is required in milling HRSAs to dissipate heat and to remove chips efficiently.

Designs such as this can help minimize downtime and maximize productivity on your shop floor.