Garr Tool, the number one manufacturer of high-performance solid carbide cutting tools in the US and Star Cutter, a carbide and preforms manufacturer, have collaborated to develop a state-of-the-art 5-axis CNC machine tool that fully automates the production of complex profile end mills right from blank to the final product.

Garr Tool has always been known for extensively using CNC automation grinding machines. All the machines they use, including Ulmer Werkzeugschleiftechnik (UWS) and Star-Cutter tool grinding machines, use control tech from NUM – one of the renowned CNC specialists. NUM and Star Cutter have worked together since 1998 to develop specialized CNC hardware and software. Almost all Star Cutter’s machines are based on NUM’s open-architecture Flexium+ CNC platform.

On the other hand, Garr Tool got into the production of large diameter tools for use on high-torque machines used in the aerospace industry in recent years. Garr Tool decided to collaborate with Star Cutter’s Elk Rapids Engineering team to develop a multi-process machine capable of handling the entire production task because that is what they need to manufacture the diameter tools.

This partnership led to the development of the Star CNC Tool grinder with NUMROTO end mill software, cylindrical grind, linear motors and drives, and all five axes on a closed-loop chiller/coolant system in 2018. Garr Tool can maintain a diameter of .001” on the OD of these tools when lights are out for 48-hour unattended runs because the machine is thermally stable.

Stars’ NXT tool and cutter grinder include similar features introduced in the Garr tool. This machine tool has five axes based on NUM’s Flexium+ CNC system and NUMROTO software. It also has linear motors and not ball screws on all three axes. The tool’s rotary axes (B and C) have direct-drive motors.

NXT also has a liquid-cooled spindle motor. Three different spindles are used with this tool for other applications, including a very high-speed unit capable of 24,000 rpm and a very high-power unit rated at 28 kW. Another major advantage of this tool is its small footprint (2,300 x 2,032 mm), making it easy to fit on small shop floors.

Even with the small footprint, NXT has a large grind zone. It has maximum X, Y, and Z travels of 500 mm, 650 mm, and 750 mm (19.7”, 25.6” and 29.5”). It can handle up to 254mm diameter parts, and 381mm work ends. NXT tool has up to 203 mm (8”) diameter wheels, making automated wheel changing and probing standard. This tool can also run up to 254 mm (10”) diameter wheels with coolant manifolds and up to 305 mm (12”) diameter wheels with no coolant manifolds.

NXT uses a modular architecture to make it easy to use with other industrial automation and handling robots. It also has many factory-built and retrofit options, such as a traveling W-axis and a 12,000-rpm wheel dresser. It should be noted that this tool’s ability to use large diameter grinding wheels for profiling applications or small, under 25 mm diameter wheels for PCD pocket grinding on the same machine makes it very flexible in production.