Каталог Dormer Pramet фрезерование 2021 - 2022 - страница 208

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9 MILLING TECHNICAL INFO Features Of The End Mill – Helix Angle Increasing the number of flutes makes the load on the single tooth A high FV can give: more homogeneous and consequently, this allows for a better finish. • Load problems on the spindle bearings But with a high helix angle, the load (FV) along the cutter axis is incre- • Cutter movement along the spindle axis. To avoid this problem it is ased too. necessary to use Weldon or better Mechanical or Hydraulical Tool- holder. FT FV General hints on milling Milling is a process of generating machined surfaces by progressively removing a predetermined amount of material or stock from the workpi- ece at a relatively slow rate of movement or feed by a milling cutter rotating at a comparatively high speed. The characteristic feature of the milling process is that each milling cutter tooth removes its share of the stock in the form of small individual chips. Type of milling cutters The three basic milling operations are shown below: (A) peripheral milling, (B) face milling and (C) end milling. B A C In peripheral milling (also called slab milling), the axis of cutter rotation is parallel to the workpiece surface to be machined. The cutter has a number of teeth along its circumference, each tooth acting like a single-point cutting tool called a plain mill. Cutters used in peripheral milling may have straight or helical teeth generating an orthogonal or oblique cutting action. In face milling, the cutter is mounted on a spindle with an axis of rotation perpendicular to the workpiece surface. The milled surface results from the action of cutting edges located on the periphery and face of the cutter. In end milling, the cutter generally rotates on an axis vertical to the workpiece. It can be tilted to machine tapered surfaces. Cutting teeth are located on both the end face of the cutter and the periphery of the cutter body. 207