Milling machines indexing fixture
Milling machines indexing fixture.
(1) The indexing fixture is an indispensable accessory for the milling machine. Basically, it is a device for mounting workpieces and rotating them a specified amount around the workpiece’s axis, as from one tooth space to another on a gear or cutter.
(2) The index fixture consists of an index head, also called a dividing head, and a footstock, similar to the tailstock of a lathe. The index head and the footstock are attached to the worktable of the milling machine by T-slot bolts. An index plate containing graduations is used to control the rotation of the index head spindle. The plate is fixed to the index head, and an index crank, connected to the index head spindle by a worm gear and shaft, is moved about the index plate. Workpieces are held between centers by the index head spindle and footstock. Workpieces may also be held in a chuck mounted to the index head spindle, or may be fitted directly into the taper spindle recess of some indexing fixtures.
(3) There are many variations of the indexing fixture. The name universal index head is applied to an index head designed to permit power drive of the spindle so that helixes may be cut on the milling machine. “Gear cutting attachment” is another name for an indexing fixture; in this case, one primarily intended for cutting gears on the milling machine.
fixtures for milling
Offset Boring Head. The offset boring head is an attachment that fits to the milling machine spindle and permits a single-edge cutting tool, such as a lathe cutter bit, to be mounted off-center on the milling machine. Workpieces can be mounted in a vise attached to the worktable and can be bored with this attachment.
milling fixture on lathe machine
Milling Machine Arbors
Shell End Milling Cutter Arbor. Shell end milling arbors are used to hold and drive shell end milling cutters. The shell end milling cutter is fitted over the short boss on the arbor shaft and is held against the face of the arbor by a bolt, or a retaining screw. The two lugs on the arbor fit slots in the cutter to prevent the cutter from rotating on the arbor during the machining operation. A special wrench is used to tighten and loosen a retaining screw/bolt in the end of the arbor.
Fly Cutter Arbor. The fly cutter arbor is used to support a single-edge lathe, shaper, or planer cutter bit, for boring and gear cutting operations on the milling machine. These cutters, which can be ground to any desired shape, are held in the arbor by a locknut. Fly cutter arbor shanks may have a Standard milling machine spindle taper, a Brown and Sharpe taper, or a Morse taper.
Standard Milling Machine Arbor.
cnc milling machine CS U4501
(a) The Standard milling machine arbor has a straight, cylindrical shape, with a Standard milling taper on the driving end and a threaded portion on the opposite end to receive the arbor nut. One or more milling cutters may be placed on the straight cylindrical shaft of the arbor and held in position by means of sleeves and an arbor nut. The Standard milling machine arbor is usually splined and has keys, used to lock each cutter to the arbor shaft. Arbors are supplied in various lengths and Standard diameters.
(b) The end of the arbor opposite the taper is supported by the arbor supports of the milling machine. One or more supports are used, depending on the length of the arbor and the degree of rigidity required. The end may be supported by a lathe center, bearing against the arbor nut (figure 4 on the previous page) or by a bearing surface of the arbor fitting inside a bushing of the arbor support. Journal bearings are placed over the arbor in place of sleeves where an intermediate arbor support is positioned.
(c) The most common means of fastening the arbor in the milling machine spindle is by use of a draw-in bolt (figure 4). The bolt threads into the taper shank of the arbor to draw the taper into the spindle and hold it in place. Arbors secured in this manner are removed by backing out the draw-in bolt and tapping the end of the bolt to loosen the taper.
manual milling machine
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