VERTICAL MILLING MACHINE

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Milling Machines, VERTICAL MILLING MACHINE, TYPES OF MILLING MACHINE, INTRODUCTION, Variety of Operations, TYPES OF VERTICAL MILLING MACHINE, Ram-Type Vertical Milling Machine, Important Factors in Determining Cutting Speed, Factors in Feed Rate, ADVANTAGES OF VERTICAL MILLING MACHINE.

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R.C.T.I. VERTICAL MILLING MACHINE:

R.C.T.I. VERTICAL MILLING MACHINE

Milling Machines:

Milling Machines Used to produce one or more machined surfaces accurately on work piece One or more rotary milling cutters Work piece held on work table or holding device and brought into contact with cutter Vertical milling machine most common Horizontal milling machine handles operations normally performed by other tools

TYPES OF MILLING MACHINE:

TYPES OF MILLING MACHINE VERTICAL MILLING MACHINE HORIZONTAL MILLING MACHINE KNEE-TYPE MILLING MACHINE UNIVERSAL HORIZONTAL MILLING MACHINE RAM-TYPE MILLING MACHINE UNIVERSAL RAM-TYPE MILLING MACHINE SWIVEL CUTTER HEAD RAM-TYPE MILLING MACHINE

VERTICAL MILLING MACHINE:

VERTICAL MILLING MACHINE

INTRODUCTION:

INTRODUCTION Developed in 1860's Combines vertical spindle of drill press with longitudinal and traverse movements of milling machine Milling process may be vertical, horizontal, angular, or helical Can be used for milling, drilling, boring, and reaming Can machine in one, two, or three planes X, Y, Z

Variety of Operations:

Variety of Operations Face milling End milling Keyway cutting Dovetail cutting T-slot and circular slot cutting Gear cutting Drilling Boring Jig boring Many facing operations done with fly cutter (cost reduction).

TYPES OF VERTICAL MILLING MACHINE:

TYPES OF VERTICAL MILLING MACHINE C-Frame Style Vertical Milling Machine Ram Type Vertical Milling Machine

Ram-Type Vertical Milling Machine:

Ram-Type Vertical Milling Machine

Parts of Ram-Type Vertical Mill:

Parts of Ram-Type Vertical Mill Base made of ribbed cast iron May contain coolant reservoir Column often cast with base Machined face provides ways for vertical movement of knee Upper part machines to receive turret where over arm mounted

Parts of Ram-Type Vertical Mill:

Parts of Ram-Type Vertical Mill Over arm round and may be adjusted toward or away from column Head attached to end of ram Made to swivel head in one plane Universal-type machines allow swivel in 2 planes Motor mounted on top of head provides drive to spindle through V-belts

Factors Affecting the Efficiency of a Milling Operation:

Factors Affecting the Efficiency of a Milling Operation Cutting speed Too slow, time wasted Too fast, time lost in replacing/regrinding cutters Feed Too slow, time wasted and cutter chatter Too fast, cutter teeth can be broken Depth of cut Several shallow cuts wastes time

Cutting Speed:

Cutting Speed Speed, in surface feet per minute (sf/min) or meters per minute (m/min) at which metal may be machined efficiently Work machined in a lathe, speed in specific number of revolutions per min (r/min) depending on its diameter to achieve proper cutting speed In milling machine, cutter revolves r/min depending on diameter for cutting speed

Important Factors in Determining Cutting Speed:

Important Factors in Determining Cutting Speed Type of work material Cutter material Diameter of cutter Surface finish required Depth of cut taken Rigidity of machine and work setup

Milling Machine Cutting Speeds:

Milling Machine Cutting Speeds High-Speed Steel Cutter Carbide Cutter Material ft/min m/min ft/min m/min Alloy steel 40–70 12–20 150–250 45–75 Aluminum 500–1000 150–300 1000–2000 300–600 Bronze 65–120 20–35 200–400 60–120 Cast iron 50–80 15–25 125–200 40–60 Free m steel 100–150 30–45 400–600 120–180 Machine steel 70–100 21–30 150–250 45–75 Stainless steel 30–80 10–25 100–300 30–90 Tool steel 60–70 18–20 125–200 40–60

Cutting Speed Rules for Best Results:

Cutting Speed Rules for Best Results For longer cutter life, use lower CS in recommended range Know hardness of material to be machined When starting, use lower range of CS and gradually increase to higher range Reduce feed instead of increase cutter speed for fine finish Use of coolant will generally produce better finish and lengthen life of cutter

Milling Machine Feed:

Milling Machine Feed Defined as distance in inches (or mm) per minute that work moves into cutter Independent of spindle speed Feed: rate work moves into revolving cutter Measured in in/min or mm/min Milling feed: determined by multiplying chip size (chip per tooth) desired, number of teeth in cutter, and r/min of cutter Chip, or feed, per tooth (CPT or (FPT): amount of material that should be removed by each tooth of the cutter

Factors in Feed Rate:

Factors in Feed Rate Depth and width of cut Design or type of cutter Sharpness of cutter Work piece material Strength and uniformity of work piece Type of finish and accuracy required Power and rigidity of machine, holding device and tooling setup

Vertical Milling Machine:

Vertical Milling Machine Versatile and easy setup Performs wide variety of operations End milling, face milling Keyway and dovetail cutting T-slot and circular slot cutting Gear cutting, drilling, boring, reaming Cutting tools used relatively small so cost lower

Aligning the Vertical head:

Aligning the Vertical head Head must be square to table (90º) Procedure to check spindle alignment Mount dial indicator on suitable rod, bent at 90º and held in spindle Position indicator over front Y axis of table Carefully lower spindle until indicator button touches table and dial indicator registers no more than ¼ revolution; set bezel to zero; Lock spindle in place

PowerPoint Presentation:

Carefully rotate spindle 180º by hand until button bears on opposite side of table; Compare readings If differences, loosen locking nuts on swivel mounting and adjust head until indicator registers approximately ½ difference between two readings; Tighten locking nuts Recheck accuracy of alignment Rotate vertical mill spindle 90º and set dial indicator as in step 3

PowerPoint Presentation:

Rotate machine spindle 180º, check reading at other end of table If two readings do not coincide, repeat step 5 until readings are same Tighten locking nuts on swivel mount Recheck readings and adjust if necessary

Procedure to Machine an Angular Surface:

Procedure to Machine an Angular Surface Lay out angular surface Clean vise Align vise with direction of feed Utmost importance Mount work on parallels in the vise

PowerPoint Presentation:

Swivel vertical head to required angle Tighten quill clamp Start machine and raise table until cutter touches work Raise table until cut desired depth Take trial cut for about .50 in. Check angle with protractor If angle correct, continue cut Machine to required depth, taking several cuts if necessary

Direction of Cut: Climb:

Direction of Cut: Climb Cutter rotation and table feed going in same direction Vertical milling: cutter tendency to pull work into cutting flutes Horizontal milling: cutter pushes work against table Maximum thickness of chip occurs at beginning of cut and exits when thin Result – chip absorbs heat generated

Direction of Cut: Conventional:

Direction of Cut: Conventional When cutter rotation and table feed are moving in opposite directions Has tendency to pull or lift work piece up from table Important that work be held securely

Direction of Cut:

Direction of Cut

ADVANTAGES OF VERTICAL MILLING MACHINE:

ADVANTAGES OF VERTICAL MILLING MACHINE Vertical milling machine offer many advantages over the older horizontal style milling machines. First, it’s important to understand the features that distinguish a vertical milling machine from the rest.Key features of vertical milling machine include:- 1) Sliding arm or rams, which allow movement of the work piece toward and away from the vertical column. 2) The spindle, motor and drive pulleys are held by a one piece tool head.

PowerPoint Presentation:

3) Knee and column support for the machine work table, which enables vertical movement of the work piece in relation to the milling tool. 4) Saddle designed to support the work table and to enable movement of the workpiece toward and away from the vertical column.

THE END:

THE END THANK YOU

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