ACTIVE LEARNING ASSIGNMENT ON MILLNG MACHINE PART-1 Prepered By: Guided ByGuided By: 130800119036 Ponkiya Kaushal Prof. Haresh Ghoniya 130800119037 Kikode Nishit N 130800119038 Lad Karan 130800119039 Makwana Chirag .

INTRODUCTION Milling: a process in which a rotating multi-tooth cutter removes material while traveling along various axes with respect to the workpiece. Figure : basic types of milling cutters & milling operations In peripheral milling (also called plain milling), the axis of cutter rotation is parallel to the workpiece surface. When the cutter is longer than the width of the cut, the process is called slab milling

Horizontal Milling M/c

Continue… FIGURE shows Horizontal milling can be performed on a horizontal-spindle milling machine. Thecutter rotates at rpm Ns , removing metal at cutting speed V. The allowance for starting and finishing the cut depends on the cutter diameter and depth of cut, d. The feed per tooth, ft and cutting speed are selected by the operator or process planner.

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Face Milling M/c

Continue… FIGURE Face milling is often performed on a spindle milling machine using a multiple-tooth cutter (n = 6 teeth) rotating Ns at rpm to produce cutting speed V. The workpiece feeds at rate fm in inches per minute past the tool. The allowance depends on the tool diameter and the width of cut.

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Continue.. Bed Type Milling Machine

Continue…. Made for deep cuts and heavy material removal, the bed only had horizontal movement Once the bed is set up, the spindle height is not changed during operation. These machines are very common due to their ease of use.

Continue…. Large Planer-type Milling Machine Planer Type Milling M/c

Continue… Planer type mills can have several heads to remove large amounts of material while the material is fed slowly into the machine. Systems are setup typically for single pass operations. These are advantageous for large work pieces requiring heavy material removal.

CNC Vertical-Spindle Milling Machine A computer numerical-control (CNC) vertical-spindle milling machine. This machine is one of the most versatile machine tools.

Cutters a. Straddle: more cutters are used to machine two parallel surfaces on the workpiece b. Form milling produces curved profiles using cutters that have specially shaped teeth Slotting and slitting operations are performed with circular cutters. [T-slot cutters, Figure 24.11 Cutters for (a) straddle milling, (b) form milling, (c) slotting, and (d) slitting with a milling cutter.

T-Slot Cutting and Shell Mill Figure 24.12 (a) T-slot cutting with a milling cutter. (b) A shell mill.

Continue…. Operations

Continue…. In Figure Shows Some basic types of milling cutters and milling operations. (a) Peripheral milling. (b) Face milling. (c) End milling. (d) Ball-end mill with indexable coated-carbide inserts machining a cavity in a die block. (e) Milling a sculptured surface with an end mill, using a five-axis numerical control machine

Continue.. Conventional Milling (Up Milling) Max chip thickness is at the end of the cut Advantage: tooth engagement is not a function of workpiece surface characteristics, and contamination or scale on the surface does not affect tool life. Cutting process is smooth Tendency for the tool to chatter The workpiece has a tendency to be pulled upward, necessitating proper clamping.

Continue Climb Milling (Down Milling) Cutting starts at the surface of the workpiece. Downward compression of cutting forces hold workpiece in place Because of the resulting high impact forces when the teeth engage the workpiece, this operation must have a rigid setup, and backlash must be eliminated in the table feed mechanism Not suitable for machining workpiece having surface scale.

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Continue….. Up Versus Down Milling Up milling or Conventional milling The cutter rotates against the direction of feed of the workpeice. The Chip is very thin at the beginning and increased along its length. The cutter tends to push the work along and lift it upwards from the table. The action tends to loosen the workpiece from the fixture. In the up milling, chips can be carried into the newly machined surface, causing the surface finish to be poorer than in down milling.

Continue….. Down milling or Climb milling the cutter rotates in the same direction as the direction of feed Advantage: The work piece is pulled into the cutter, eliminating any effects from looseness of the work table feed screw. There is less tendency for the machined surface to show toothmarks, and the cutting process is smoother, with less chatter. The cutting force tends to hold the workpiece against the machine table, permitting lower clamping force. Disadvantage: The maximum chip thickness is at the point of tooth contact with the work piece. Dulling the teeth more quickly, especially for workpiece with a hard surface.

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Geometry of Milling Cutter…. Continue…. Geometry of Milling Cutter…. IN NEXT SLIDE….

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