The “Indirect” Machine Tool Investment

Would your shop purchase a CNC machine tool that would never be used to make a sellable end-use part? Russell Riddiford says he has seen a steady increase in the number of machining facilities choosing to do this very thing. He is the president of the U.S. business unit for ANCA. The machine tool in question is a CNC tool grinder.

Traditionally, these machines are sold to cutting tool manufacturers and regrinding services, and these companies still make up the largest market. Yet several factors have made in-house CNC tool grinding increasingly attractive for manufacturers that use a sizable volume of tooling. The machines have become less expensive over the years, and ANCA (like other tool grinder makers) has steadily improved its control interface to make the machine easier to use—to the point that a sophisticated understanding of cutting tool design is no longer needed, because that knowledge is built into the machine’s software. What’s more, the pressure to reduce inventories has led many manufacturers to take control of their tool inventory by controlling their own regrinding.

The shop that considers adding in-house tool grinding typically faces an investment decision unlike that of any machine tool the shop has purchased before, Mr. Riddiford says. A machine tool is usually purchased because the production demand directly justifies it. Either there is a new job demanding a new machine, or some existing job needs to be produced at a higher rate. By contrast, the tool grinder makes an indirect contribution to the plant’s machining. It does not directly produce any part number the shop is tasked with delivering. As a result, just figuring out which area of the shop will give up floor space for this machine can be a challenge.

Invariably, he says, any resistance or hesitation about the tool grinder fades. Usually this is because the machine provides the shop with a freedom it never had before—the freedom to quickly produce and experiment with custom tool geometries. By tailoring tools to its jobs, the shop is able to improve the effectiveness of its processes in ways that it might never have previously considered.

Mr. Riddiford notes that in-house tool grinding is actually one of two non-traditional markets for tool grinders that have grown more active recently. The other is manufacturing medical implants. The precise multi-axis grinding platform that is effective for producing drill and end mill geometries also happens to be effective for producing the complex geometries of artificial knees, heart valves and other implanted components. Here, he says, it is his company that is challenged to think differently about the machine. The company continues to allocate engineering resources to this market as the medical machining demand grows. For ANCA, the significant difference in this application is that, in this case, the machine is being used to make a finished, end-use part.