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Mass customization is driving demands for small-diameter milling, drilling and reaming applications where space is a restriction for insert-type cutting tools.

Many of these applications, approximately 0.25-in diameter and larger, require highly accurate round tools with fixed, brazed tips of polycrystalline diamond (PCD) or polycrystalline cubic boron nitride (PCBN) that can hold 3- to 5-micron tolerances on diameter.

Achieving such tolerances with inserted-type cutting tools is difficult because of possible cutting-edge movement. Presetting multiple-tipped inserted cutter bodies also consumes time and depends heavily on skills of the operator.

Custom tooling addresses all of these issues, but the industry norm on delivery lead times for designing, prototyping and fabricating custom tooling typically runs from 14 to 28 weeks. Why so long? Part of this is due to tool concepts being created by the end user that must be re-designed by the tooling supplier to have proper clearances and be "manufacturable."

Not any more.

One tooling supplier has automated this entire process using proprietary CAD/CAM software that helps shorten lead times by half or more. CITGO simply inputs the finish workpiece dimensions into the program, along with the number of flutes, the spindle-connection style (any DIN standard shank, HSK, CV, ABS, KM, BT, DV straight shank, or custom shank), and the PCD or CBN segment design.

The software develops the workpiece geometry and immediately renders a finished print tool profile with clearances, secondary angles and flute design. The file is then sent electronically for a 3D solid model that can be viewed on-line. The weight and center of tool are also identified, which is especially valuable to higher-tech users utilizing the latest high speed machining techniques.

This eliminates having to manufacture a prototype of the tool. Many traditional end users may initially be uncomfortable with the perceived lack of prototyping, but the prototype tool is actually the solid 3D model.

Data from the tool design program is then used to rapidly produce a scale model of the tool for approval. As the tool is being designed, the CNC program is written in the background and downloaded via email. Since the CNC program and the CAD print are one and the same, potential programming errors are eliminated because the software checks for any bore clearance issues.

If interference is detected, the user is alerted and advised how much to raise the cutting height to clear the required bore. This saves more engineering time, reduces the need for a CNC programmer and slashes several days from the entire process.