1. UNIT-I SLOTTING MACHINES

2. Slotting machine

3. Slotting machine is also called as Slotter

4. Line diagram of slotter
CROSS
SLIDE
SADDLE

5. Slotters

6. Slotter A Machine which produces flat surfaces
A Ram holding the Tool reciprocates
Ram reciprocates in vertical direction
Work is fed perpendicular to the tool

7. Slotter - working principle
TOOL B A
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

8. 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

9. WORKING PRINCIPLE – contd.
Work is supported on a rotary table.
Table can have longitudinal and rotary movements
Straight and rotary cuts can be produced.

10. CLASSIFICATION According to design and purpose the slotters
are classified into two types
Puncher Slotter
Precision tool room Slotter
Puncher slotter:
Intended for removing large amount of metal from heavy works.
heavy and rigid machine
Ram driven by rack and spiral pinion mechanism
used for machining large castings and forgings

11. Production slotter

12. Precision tool room slotter:
Used for tool room work, where accuracy important
Lighter in construction
Fitted with quick return mechanism
Operates at high speeds and designed for light cuts
Gives accurate finish
Suitable for small to medium size work pieces

13. Difference between vertical shaper and Slotter
in vertical shaper the tool holding ram can tilt by about 100 with respect to vertical axis
In slotter ram cannot tilt at all.
In all other aspects vertical shaper and slotter are similar

14. Slotting machine Introduction
Having known the Working Principle we will now look at :
The Constructional Details of a slotting Machine
Function of each part
Specifications of a slotter
M305.30

15. Slotting machine -construction
RAM
COLUMN
TOOL HEAD
T-SLOTS
CIRCULAR TABLE
CROSS SLIDE
SADDLE
BASE
M305.30

16. Slotting machine
M305.30

17. Line diagram of slotter

18. Main parts of a slotter 1. Base 5. Cross slide 2. Column 6. Saddle
3. Ram Tool head
4. Table

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

20. Base Rigidly built to take up cutting forces
Top of bed is accurately finished
Guide ways are provided for saddle
Guide ways are perpendicular to column face

21. Column Vertically mounted on the base Houses Driving Mechanism of Ram
Has guide ways on which Ram slides
Made of Cast Iron
Also houses feeding mechanism
COLUMN

22. Ram Reciprocating vertically up and down of a slotter
Mounted on guide ways of column
It carries Tool Head / cutting tool
Connected to Driving Mechanism
An arrangement is provided on the body of ram to change length of stroke
R A M
M305.30

23. Table It holds the work piece.
A circular casting with T-slots on its top
Movement of table can be linear or rotary
Table is graduated in degrees so indexing can be done
Slotter vice may be fitted in the T-slots
Work may be fixed in the vice
Operated manually or by power
TABLE

24. Saddle It is mounted on guide ways of bed
It can be moved towards or away from bed
Using saddle longitudinal feed is given
Top is accurately finished to provide guide ways for cross slide
These guide ways are perpendicular to the guide on the base
Operated either manually or by power

25. Cross slide Circular work-table is mounted on the top.
Mounted on guide ways of saddle
Moves parallel to the face of the column
Using cross slide cross feed is given
Operated either manually or by power

26. Tool head It is attached to the bottom end of Ram
Carries Tool post on it
Tool is fixed in position
No swiveling along verticle axis or horizontal axis

27. Specifications of Slotting machine
Max. length of Ram Stroke
Diameter of work table in mm.
Type of Drive
Maximum table travel.
Power input
Floor Space required

28. Specification

29. Slotter driving mechanism
A Slotting machine produces flat surfaces
The Ram holding the Tool reciprocates vertically up and down
Cuts the material only in down stroke
There should be some mechanism to move the ram in reciprocating motion
It is called as slotter driving mechanism
The mechanism commonly used is slotted disc mechanism

30. Slotted disc mechanism

31. Quick return mechanism (QRM)
A Mechanism makes the ram to move slowly during cutting stroke.
During return stroke ram moves at a faster rate.
To reduce the idle time,It Should return quickly .
The mechanism adopted is known as QRM

32. Methods to obtain Q.R.M. in slotter
1. Whitworth Q.R.M. Mechanism
2. Variable speed reversible motor drive mechanism
3. Hydraulic drive Mechanism
The mechanisms for QRM in slotter are similar to QRM in shaper

33. Feed in Slotter In Slotter feed is given by table
Feed movement is intermittent
Feed is given at the beginning of the cutting stroke
Feed may be given either manually or by power
Table will have three types of feed movements
a. longitudinal
b. cross and
c. circular feeds.
Contd…

34. Types of feed in Slotter
Longitudinal feed:
Table is fed perpendicular to the column
Table moves towards or away from the column
Cross feed:
Table is fed parallel to the face of the column
Circular feed:
table is rotated with respect to verticle axis

35. Feed mechanism of a Slotter
Feed shaft

36. Feed mechanism of a Slotter
Uses a ratchet and pawl mechanism
Feed shaft engaged with cross, longitudinal / rotary feed screws has the ratchet mounted on it.
Ratchet is moved by small amount in one direction only with the help of a connecting rod, lever.
The roller moves in the cam groove cut on the face of the bull gear of slotting machine.

37. Operations on slotter 1. Machining flat surfaces
2. Machining Circular Surfaces
3. Machining internal surfaces
4. Machining grooves or key ways

38. Setup 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
Contd…

39. Setup 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

40. Machining Flat Surfaces
Fix the work properly on the table
Adjust the length of stroke
Set the required cutting speed
Give required feed of the table
Tool is held in the tool head of ram
Ram reciprocates up and down

41. Machining Flat Surfaces
Feed has to be given at the beginning of cutting stroke
Both internal and external surfaces can be machined
Give suitable depth of cut for rough cuts
Finishing the job by giving less depth of cut

42. Machining flat surfaces

43. Machining circular surfaces
Tool is set radially on the work
Work piece is placed centrally on the rotary table
Feed is given by the rotary table feed screw
Feed screw rotates the table through an arc
Adjust the length of stroke
Set the required cutting speed
Finishing the job by giving less depth of cut

44. Machining internal surfaces
Fix up a tool in tool post
Cross, longitudinal and rotary feed are combined
Any contoured surface can be machined
Mostly done manually
Good skill is required from operator

45. Machining grooves or key ways
Slotter is specially intended for cutting internal grooves
External or internal gear teeth can be machined
Fix up the job between two centers
Cut first a key way
Move / Rotate work by the required amount
Indexing can be done by using graduations on rotary table

46. 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

47. Cutting Key ways