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Home , Facing (machining), Lathe, Machine tool, Machining, Turret lathe

MACHINING OPERATIONS AND 1. and Related Operations 2. and Related Operations 3. 4. Machining & Turning Centers 5. Other Machining Operations 6. Shape, Tolerance and 7. Machinability 8. Selection of Conditions 9. Product Design Consideration

1 1. Turning & Related Operations

• Turning – a machining v N = process in which a Rotational Speed: πDo single-point remove =− 2dDD material from the fo = Nff surface of a rotating Feed rate: r work piece. () L Time of machining: T = m f Material Removal Rate: r v = vfdMRR D o Df d f L 2 Operations related to Turning

Contour turning Chamfering

Facing Taper turning Form turning

Threading Drilling Cutoff Knurling

3 Work Holding • Mounting between two centers (Dog & Live center)

•

• • Face plate

4 Engine Lathe Headstock

Tool post

Carriage Bed

Threaded Lead

5 Other & Turning Machine

• Toolroom Lathe and Speed Lathe • – The tailstock is replaced with a turret • Chucking – No tailstock • Automatic Bar Machine – Similar to chuck machine but with a collet – A single- and multiple- bar machines • NC Lathe

6 Boring Machining

• Boring – Cutting is done inside diameter of the work material

Horizontal Boring Machining Vertical Boring Machining

7 2. Drilling & Related Operations • Geometry of Twist – Shank, Neck and Drill body – Helix angle, Point angle, Flute, cutting edge, edge, Margin • Cutting conditions v f(in/rev) Spindle: N = Feed rate: r = Nff πD π 2 fD Metal Removal Rate: MRR = r + At 4 Machining time: Tm = f For a through A d r T = t d m For a blind hole fr 8 Twist Drill and Drilling Operations

From Kalpakjian and Schmid (2003) 9 for drilling

• Drill press – Upright drill – Bench drill – Radial drill – Gang drill - 2-6 together – NC drill • Vice, and

10 3. Milling

Up Milling Down Milling • Milling Conventional face – A machine operation in which a work part is fed past a rotating cylindrical tool with multiple edges. (milling machine) Partial face Slab • Types – Peripheral milling End • Slab, slotting, side and slotting straddle milling Profile • Up Milling (Conventional) & down milling (Climb) – milling side Contour • Conventional face, Partial face, End, Profile, Pocket & Pocket contour millings straddle Face Milling Peripheral Milling 11 Cutting conditions

• Milling cutters – Plain milling cutters – Form milling cutters Radial Rake Angle – Face milling cutters Relief Angle – End milling cutters Clearance Angle • Cutting conditions v N = Spindle rotation speed: πD

Feed rate: = tr fNnf Material Removal Rate: = wdfMRR r 12 Milling Machines

• -and-column Milling Machine – Horizontal and Vertical types – Universal and Ram types • Bed-type Mill • -type Mills – the largest Horizontal Vertical category • Tracer (profile) Mill – reproduce an irregular part geometry • CNC Milling machine

Universal Ram

Bed-type mill

13 Machining Centers

• Machining center – highly automated machine tool capable of performing multiple machining operations under CNC control. – Automatic tool changer – Pallet shuttles – Automatic workpart positioning • CNC turning center

14 A CNC mill-turn center

A series of operations without human interactions

Stock Turning Milling Drilling

A part

From a From a round stock From another casting 15 5. Other Machining Operations

• Shaping and planing – A single-point tool moves linearly relative to the work part – Shaping - A tool moves – Planing – A workpart moves

• – Performed by a multiple-tooth by moving linearly relative to the work in the direction of the tool axis. • Sawing – Hacksawing, Bandsawing, and Circular sawing

16 Broaching

Semifinishing teeth

Finishing teeth Roughing teeth

17 Sawing

Hacksaw - linear reciprocating motion

Bandsaw - linear continuous motion

Saw Blade (Straight & Undercut tooth or Straight & Raker sets) 18