1. UNIT-I SHAPING MACHINES

2. Shaping Machine is also called
Shaper

3. What is a shaper ? A Machine which produces flat surfaces
A Ram holding the Tool reciprocates
Work is fed perpendicular to the tool

4. Shaper - working principle
TOOL B A
In the shaper, the cutting tool has a reciprocating motion, and it cuts only during the forward stroke.
Cutting Tool repeatedly travels along line A B
Work is fed a small distance each time
Feed of work & line of tool motion are in same plane but perpendicular

5. Working principle – Contd.
The tool line eventually reaches position C D
Combination of two movements results in the flat plane ABCD being machined B A D C

6. Classification of shapers
Basic types:
Horizontal Shaper
Vertical Shaper
Traveling head Shaper

7. Traveling head shaper:
Horizontal shaper:
Ram holding the cutting tool moves In horizontal plane
Vertical shaper:
The cutting tool moves in vertical plane
Traveling head shaper:
Cutting tool reciprocates & moves cross wise simultaneously.

8. Detailed classification
HORIZONTAL
SHAPERS
1. Acc. to Cutting
Action of Stroke
2. Acc. to the
Table Design
3. Acc. to Driving
Mechanism

9. a) Crank type 3. Acc. to Driving Shaper Stroke action
a) Push Type Shaper
1. Acc. to Cutting
Stroke action
b) Draw Type Shaper
a) Standard Shaper
2. Acc. to the
Table Design:
b) Universal Shaper
a) Crank type
3. Acc. to Driving
Mechanism: b) Geared type
c) Hydraulic
Shaper
M305.23

10. Push type shaper Metal is removed when the ram moves away from column
Most common type used in practice
Unless otherwise specified, the term shaper refers to Push type Shaper

11. Draw type shaper
Metal is removed when the tool is drawn towards the column
Allows heavier cuts to be made
Less vibration during cutting

12. Standard shaper Universal shaper
Work Table can be moved Vertically & Horizontally.
it cannot swivelled or tilted.
Universal shaper
Table can be moved
Horizontally
Vertically
Swivelled &
Tilted
This is mostly used in Tool Rooms

13. Crank type shaper: Geared type shaper: Hydraulic shaper:
Driving mechanism is by crank and a slotted lever quick return motion mechanism is used to give reciprocating motion to the ram.
The crank is adjustable and is arranged inside the body of bull gear.
Geared type shaper:
Driven by Rack & Pinion mechanism
Hydraulic shaper:
Driven by oil pressure developed by a pump, which is run by an electric motor.
It is more efficient than the crank and geared type shapers.

14. SHAPING MACHINE - Working

15. SHAPING MACHINE - PARTS
TOOL
RAM
TABLE
COLUMN
CROSS RAIL
BASE

16. Main parts of a shaping machine
1. BASE CROSS RAIL
2. COLUMN SADDLE
3. RAM TOOL HEAD
4. TABLE CLAPPER BOX

17. Constructional details of a shaper
RAM
TOOL HEAD
RAM CLAMP
TOOL POST
CLUTCH
CROSS RAIL
COLUMN
TABLE
BASE
BASE

18. Parts - functions 1. Base Bottom most part
Supports other parts of the machine
Acts as a reservoir of lubricating oil
Made of Cast Iron
BASE

19. 2. Column Vertically mounted on the base
Houses Driving Mechanism of Ram
Has guide ways on which Ram slides
Made of Cast Iron
COLUMN

20. 3. Ram The main moving part of a Shaper It carries Tool Head R A M
Connected to Driving Mechanism
R A M

21. 4.Table A box like casting with T-slots on its top
Shaper vice is fitted in the T-slots
Work is fixed in the vice
TABLE

22. 5. Cross rail Used to move the Table Up & Down
Upward movement is controlled by an Elevating Screw
Side movement is controlled by lead screw
CROSS
RAIL

23. 6. Saddle It is mounted on cross rail It supports the Table
Moves across the cross rail left to right
Movement obtained by a cross feed screw
SADDLE
CROSS RAIL

24. 7. Tool head It is attached to the front end of Ram
Carries Clapper box & Tool post on it
Can be swiveled at any angle on either side
TOOL HEAD
TOOL POST
CLAPPER BOX

25. 8. Clapper box It is hinged to the tool head It houses clapper block
Swings outward in return stroke
Tool post mounted on clapper block
CLAPPER
BOX

26. Specifications of Shaping Machine
Max. length of Stroke of Ram
Type of Drive
Power input
Floor Space required
Weight of the Machine
Cutting to Return Stroke ratio
Feed
Size of table
Maximum horizontal and vertical travel of the table

27. Working of shaper
Shaper drive Mechanism changes rotary motion of power source (Electric motor) to reciprocating motion of Ram.
Material removal (cutting) of work piece takes place in the forward stroke of ram.
The return stroke of the ram does no cutting, hence is called Idle stroke.
The Ram with cutting tool has to move slowly in cutting stroke.

28. Working of shaper
Since return stroke does no cutting the ram should move faster during return stroke.
The shaper drive system incorporates quick return mechanism. So that the ram moves faster during return stroke
Thus minimizing the (idle time) Quick Return time.

29. Shaper Operations Machining Horizontal Surfaces
Machining Vertical Surfaces
Machining Angular Surfaces
Cutting Slots, Grooves & Key ways
Machining irregular surfaces
Machining Splines / Cutting Gears

30. Steps for Machining Work is properly held in a vice
Table is raised to a gap of 25 to 30 mm between tool & work
The length & position of stroke are adjusted
The length of stroke should be nearly 20 mm longer than the work

31. Steps for Machining
The approach & over run should be 10 & 5 mm respectively.
Depth of cut is adjusted by rotating down the feed screw of tool head
Feed is adjusted about half the width of cutting edge of tool

32. Machining Horizontal Surfaces
Fix the work properly on the table
Adjust the length of stroke
Set the required cutting speed
Give required feed of the table
Fix an appropriate tool in the tool head
Give suitable depth of cut for rough cuts
Finishing the job by giving less depth of cut

33. Machining Horizontal Surfaces

34. Machining Vertical Surfaces
Fix up the job on the table firmly
Align the surface to be machined properly
Fix up a side cutting tool in the tool head
Set the vertical slide exactly at zero
Swivel the apron away from the job
Switch on the machine
Rotate down feed screw by hand to give down feed
Feed in about 0.25 mm

35. Machining Vertical Surfaces

36. Machining Angular Surfaces
Angular shaping is carried out to machine inclined surfaces, bevelled, dove tail etc.,
Set the work on the table
Swivel the vertical slide of tool head to the required angle ( to the left or right)
Set apron away from work
Give down feed as per requirement

37. Machining Angular Surfaces

38. Cutting Rack or Splines
Fix up a square nose tool in tool head
Adjust the length & position of stroke
Reduce the cutting speed
Give suitable depth of cut
Feed the work properly to get equal splines

39. Cutting Rack or Splines

40. Cutting Key ways Fix up the job between two centres
Cut first spline similar to a key way
Move / Rotate work by the required amount
Use index plate for this purpose

41. Cutting Key ways (At the end)

42. Cutting Key ways (Midway)

43. Machining irregular surfaces
Fix up a forming tool in tool post
Give cross feed in conjunction with down feed
Swivel the apron suitably according to the contour required

44. Machining irregular surfaces
TOOL
WORK

45. Advantages and limitations of shaper
The set up is very quick and easy and can be readily changed from one job to another.
The work can held easily.
The single point tools used are in inexpensive;
These tools can be easily grounded to any desired shape.
Lower first cost.
The cutting stroke has a definite stopping point.
Because lower cutting forces, thin and fragile jobs can be conventionally machined on shapers.
Limitations
By nature is a slow machine because of its straight line, forward and return stroke. The single point tool requires several strokes to complete a work.
The cutting speeds are not usually very high speeds of reciprocating motion due to high inertia forces developed in the motion of the units and components of the machine. Owing to these reasons the shaper does not find ready adaptability for assembly and production line.

46. Shaper Driving Mechanisms
Whitworth quick return mechanism
Slotted link quick return mechanism
Hydraulic quick return mechanism

47. Quick Return Mechanism
Q.R.M

48. Whitworth Quick Return Mechanism

49. Whitworth Quick Return Mechanism

50. Whitworth Quick Return Mechanism

51. Whitworth Quick Return Mechanism

52. Whitworth Quick Return Mechanism
Crank BC revolves at a uniform speed.
During cutting stroke point C travels from Y to X through Z.
Ram returns at high speed as the crank rotates from X to Y through T.
Then:
Time for cutting stroke Ø
Time for return stroke Ø
Since Ø is smaller than 360 – Ø, the time for cutting is more than the idle time.
Stroke length can be changed by varying the radius AE =

53. Crank & Slotted Link

54. Crank & Slotted Link QRM

55. Main Parts of the Mechanism
BEVEL GEARS
LEAD SCREW
CRANK PIN
BULLGEAR SLIDE
BULLGEAR SLIDING BLOCK
ROCKER ARM SLIDING BLOCK
BULLGEAR

56. Line diagram of Crank & Slotted lever Mechanism
Clamping lever
Bevel Gears
Ram
Ram Block
Slotted Lever
Bevel Gears
Bull gear Sliding block
Driving Pinion
Crank pin
Lever Sliding block
Lead Screw
Bull gear Slide
Bull Gear
Pivot

57. Elements of the Mechanism
Crank pin(11) is fitted in the slotted link(9)
Bottom end of slotted link (rocker arm) is attached to frame of column(15)
Its upper end is connected to ram(2).

58. Working Principle Electric motor drives pinion (1)
Pinion (1) drives the bull gear(14)
A Radial slide (16) is bolted at the centre of bull gear.
Radial slide carries a sliding block(12) & a crank pin (11)
As the bull gear 14 rotates, crank pin 11 rotates.
So sliding block 12 also rotates on the crank pin circle.
Simultaneously crankpin will move up & down in the slot of the slotted link 9.

59. Working Principle - concluded
As the crank pin11 moves, slotted link 9 gets rocking movement.
This rocking movement is communicated to the ram.
Thus the rotary motion of the bull gear is converted to reciprocating motion of the ram.

60. PRINCIPLE OF Q.R.M. P M N K O L C2 C1

61. Principle - Explained
When the link is in the position PM, ram will be at the extreme backward position.
When it is at PN, ram is at extreme forward position. P M N K O L C2 C1

62. Principle - Continued
PM&PN are tangents drawn to the crank pin circle.
Forward cutting stroke takes place through the angle C1K C2
Return stroke takes place through the angle C2 L C1 of the crank.
It is evident that angle C2K C1
is greater than C2 L C1 P M N K O L C2 C1

63. Principle - Concluded Angular velocity of crank pin is constant.M N K O L C2 C1
Angular velocity of crank pin is constant.
So Return stroke is completed in a shorter time.
Therefore it is known as quick return motion.

64. Ratio between cutting time & return time.K O L C2 C1
Cutting time : Return stroke = Angle C1KC2 : Angle C2LC1
Cutting time : Return time ratio
usually varies bet 2 : 1.
Practical limit is : 2

65. Hydraulic drive

66. Hydraulic drive
Quick return in the hydraulic shaper is accomplished by increasing the flow of hydraulic oil during the return stroke.
In the hydraulic shaper the ram is connected to the hydraulic cylinder which is controlled by means of a 4 way valve.
The hydraulic fluid is pumped to the hydraulic cylinder through 4 way valve; this valve is connected to the sump.
The 4 way valve controls the direction of high pressure fluid into the cylinder and controls the direction of motion, either the cutting stroke or return stroke.

67. Hydraulic drive
The flow control valve controls the flow rate of the hydraulic fluid thereby controlling the speed at which ram moves.
Since the power available remains constant throughout, it is possible to utilize the full capacity of the cutting tool during the cutting stroke
The starting and stopping of the machine is achieved by through a finger operator lever.
An adjustable trip dog operated lever controls the operation of 4 way valve to control the ram reversible.
The return or idle stroke is faster than the cutting stroke because of the smaller area in the return side of the cylinder if constant volume pump is used.

68. Advantages of hydraulic drive
The cutting stroke has a more constant velocity and less vibration is induced in the hydraulic shaper.
The cutting speed is generally shown on an indicator and does not require calculation.
Both the cutting stroke length and its position relative to the work may be changed quickly without stopping the machine.
The hydraulic feed operates while the tool is clear of work.
More strokes per minute can be achieved by consuming less time for reversal and return strokes.

69. Disadvantages
The stopping point of the cutting stroke in a hydraulic shaper can vary depending upon the resistance offered to cutting by the work material.
It is more expensive compared to the mechanical shaper.