Conventional lathe mc

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Conventional machiningConventional machiningis a collection ofmaterial-working processes in which power-driven machine tools, such as saws, lathes,

milling machines, and drill presses, are usedwith a sharp cutting tool to mechanically cutthe material to achieve the desired geometry.

Machining is a part of the manufacture ofalmost all metal products, and it is commonfor other materials, such as wood and plastic,to be machined.


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Machining operations

Turning operations are operations that rotate the workpieceas the primary method of moving metal against the cuttingtool. Lathes are the principal machine tool used in turning.

Milling operations are operations in which the cutting toolrotates to bring cutting edges to bear against the workpiece.

Milling machines are the principal machine tool used inmilling.

Drilling operations are operations in which holes are

produced or refined by bringing a rotating cutter with cuttingedges at the lower extremity into contact with the workpiece.Drilling operations are done primarily in drill presses butsometimes on lathes or mills.


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Conventional lathe machine

Removal of metalfrom work piece to

get the requiredshape

Tool should beharder than the

material of thework piece


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Types of lathe

Speed lathe Wood working Centering Polishing Spinning

Engine lathe

Belt drive Individual motor drive Gear head lathe

Bench lathe Tool room lathe

Capstan lathe and turret lathe Special purpose

Wheel lathe Gap bed lathe T-lathe

Duplicating lathe Automatic lathe


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LATHE PARTS

1. Bed

Rigid enough to withstand the cutting pressure

Massive with sufficient depth and width to absorb

vibrations On the top there are 2 slides r giudeways

outerways provides sliding surface 4 carriage

Innerways for the tailstock

Suitable material cast iron alloyed with nickel nchromium


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2. Headstock Left end of the lathe bed

Provides rotation at multiple speeds

Comprises of a hollow spindle

3. Tailstock

Right end of the bed

Supports the other end of the work when it s beingmachined between the centres

Holds the tool for performing operations lyk drilling,tapping, reaming, etc,.


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4. Carriage

Support, move and control the cutting tool

Consists of Saddle- H-shaped casting, carries the tool post n cross slide

Cross slide

Compound rest

Tool post


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LATHE ACCESSORIES

Accessories include

1. Carriers and catch plates Drive the workpiece when it s held between two centres

2. Chucks

Holds n rotates a piece of work in the lathe Different types r available lyk 4-jaw, 3-jaw, air operated, drill n

magnetic chucks

3. Face plates Holds work piece in those cases wer it s not convinient with

chucks r centers

4. Mandrel Holds n rotates hollow work piece


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LATHE OPERATIONS1

. Turning2. Chamfering

3. Thread cutting

4. Facing

5. Knurling6. Filing

7. Polishing

8. Spinning

9. Drilling

10. Boringusing special attachments even grinding n milling

operations can be performed


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Grinding MachineMetal cuttingoperation

Rotating abrasivewheel acts as tool

High surfacequality

Accurate shapeand dimension


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The Grinding wheel

Abrasives Natural -sandstone, emery, corundum, diamond

Artificial aluminium oxides, silicon carbides

Bonds Adhesive substance hold abrasive grains together in the form

of grinding wheel

Vitrified bond : gud strength and porosity, allows high depth ofcut

Silicate bond : useful wen the heat evolved s to be held at theminimum

Resinoid bond : synthetic resins, used in the manufacture ofwheels used at high cuttting speeds


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Characteristics Grit or grain size- size of the sieve thro which grains pass

Grade 10 s coarse, 100 s fine, 600 s very grade

Structure spacing between abrasive particles.


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Millingmachine

Process in which thework piece s advanced

with a suitable feed rateto a multi point cutterrotating atcomparatively highspeed, with the cutteraxis of rotation in a fixed

position


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Types of milling machine

1. Column and knee type

a) Hand milling mc

b) Plain milling mc

c) Universal milling mc

d) Omniversal milling mc

e) Vertical milling mc

2. Fixed bed type

3. Planer type

4. Special type

a) Rotary table

b) Pantograph, profiling & tracer controlled


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Milling Machine Operations

End Milling Operation

Milling cutter used s called end mill

Resembles drill bit in shape

Remove material from side surfaces

Plain Milling Operation

Removes material from top(flat) surface

Also called slab milling

Both horizontal n vertical surfaces can be machined

Cutter used s side n face cutter

Special Operations Straddle milling(two r more cutters)

Form milling

Slotting n slitting

T-slot milling


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DRILLING MACHINE

Holes can be drilled at low cost

Also called drill press

It is the operation of producing acircular hole in a work by using arotating cutting tool known as thedrill.


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Radial drilling machine


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Types of Drilling Machine

portable drilling machine

Sensitive drilling machine

Upright drilling machine

Radial drilling machine Gang drilling machine

Multiple spindle drilling machine

Automatic drilling machine

Deep hole drilling machine


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Drilling Machine Operations

Drilling

Reaming

Boring

Counterboring Countersinking

Spot facing

Tapping

Grinding

Trepanning


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Drilling machine tools

Drill fluted cutting tool used to originate or enlarge ahole in a solid material

Types of drill1. Flat or spade drill- used wen the same size twist drill s not

available Each time the drill s ground the diameter changes

Chips do not come out automatically

2. Straight fluted drill- has grooves r flutes running parallel to thedrill axis Used for drilling brass, copper n other soft materials

Zero rake

3. Two- lip twist drill- commonly used End cutting tool


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4. Taper shank core drill- enlarge the cored, punched or drilledholes Often used as roughing reamer

5. Oil tube drill- used for drilling deep holes

Cutting fluid r compressed air s forced thro the holes to the cutting pointof the drill to remove the chips

6. Centre drill Used when centre holes r drilled on the ends of a shaft

Drill material High speed steel or carbon steel


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Conventional lathe mc