Preparations for milling and machining

  • Reasons behind the choices Cosina makes

There are a number of attachments on a machine tool that resemble drill bits. If you look closely at them, you realize that they are all different. These tools are used for end-milling. Where as a drill moves the bit only in the axial direction, and end-mill can additionally cut in the horizontal direction, which enables metal to be milled into complex shapes.

The piece of equipment that automatically mounts and controls these cutting tools according to a set program is called the “machining center.” At Cosina’s Nakano factory in Nagano, there are a number of machining centers and other types of milling machines, most of which are customized and not the standard general-purpose models from machine manufacturers.

Drills and end-mills mounted on a machining center

The purpose of using customized equipment is to improve processing accuracy. Though machining requires more time than a general-purpose machine, it ensures the dimensional accuracy required of high-end optical products that must pass stringent quality inspections, thus improving productivity. High-cycle mass-production sacrifices high precision machining. Cosina does not make products like that.

Is the ultimate in processing equipment all that is needed to make high-end products? We think it takes more than that. You have to know the differences between soft and hard metals. You have to select the right tool to process the source metal. Certain tools cut better in certain directions. Even changes in cutting oil temperature can affect product finish.

Lens barrel after milling

Sharp tools must be readied and chucks that firmly grip the tools but do not interfere with workpieces must be selected. Cutting oil temperature has to be set according to the subtle seasonal changes in outdoor air temperature and machine running time. Milling and machining have to be done with extreme precision. There can be no compromises when preparing production to achieve the Cosina’s standards.