Shaping

1. © rkm2003
Shaping, Planing
Shaping, Planing
Shaping, Planing
Shaping, Planing
and Slotting
and Slotting
and Slotting
and Slotting
Operations
Operations
Operations
Operations
Chapter 7

2. © rkm2003
Production of Flat
Production of Flat
Production of Flat
Production of Flat
Surfaces
Surfaces
Surfaces
Surfaces
Typical components with flat surfaces

3. © rkm2003
Production of Flat Surfaces..
Production of Flat Surfaces..
Production of Flat Surfaces..
Production of Flat Surfaces..
Motions for producing Flat Surface
A
D
Feed
A'
Cut
E
B
'
B
C
Workpiece
De
pth
of
cu
t

4. © rkm2003
Reciprocating Machine
Reciprocating Machine
Reciprocating Machine
Reciprocating Machine
Tools
Tools
Tools
Tools
• different from rotary machine tools
• A single-point tool moves linearly
relative to the work part
•Shaper Shaping tool moves
•Planer Planing workpiece moves
•Slotter

5. © rkm2003
Shaper/
Shaper/
Shaper/
Shaper/Shaping Machine
Ram
Tool
Workpiece
Vise
Base
v
Table
f or d
Tool head
d or f
Column

6. © rkm2003
Shaper/
Shaper/
Shaper/
Shaper/Shaping Machine
Main Parts
Base
Column – drive, support & guide ram
Table – hold & feed workpiece
Ram – tool head, clapper box
Types of Shaping M/c
• Horizontal Shaper
• Vertical Shaper (Slotting M/c)

7. © rkm2003
Shaping Operation
Shaping Operation
Shaping Operation
Shaping Operation
Cutting action and functioning of
clapper box in a shaper
Tool cleared
from machined
surface
Clapper box
Workpiece
(b) Return stroke
Lifted
clapper
box
(a) Forward/Cutting stroke

8. © rkm2003
Shaping Operation..
Shaping Operation..
Shaping Operation..
Shaping Operation..

9. © rkm2003
Shaping Operation ..
Shaping Operation ..
Shaping Operation ..
Shaping Operation ..
Machining of inclined surface on shaping
machine
θ
Tool
θ
Workpiece
Inclined
machined
surface
Tool head & slide
(axis parallel to
machined surface)
Clapper box
(axis away from
toolhead)
Tool holder
located at a
convenient angle
Depth of cut
Movement
of the slide
for feed

10. © rkm2003
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Shaping Machine
Shaping Machine
Shaping Machine
Shaping Machine
m/min
where
N = the number of double strokes or cycles
of the ram per min (one double or full stroke
= one cutting and one return stroke)
L = Length of the ram stroke in mm
m = return stroke time/cutting stroke time
1000
)
1
( m
L
N
v
speed
cutting
+
=

11. © rkm2003
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Shaping Machine
Shaping Machine
Shaping Machine
Shaping Machine ..
Length of Stroke L = Lj + 2 c
Workpiece
c c Clearance
Return Stroke
Cutting Stroke
Length of stroke L
Lj

12. © rkm2003
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Shaping Machine ..
Shaping Machine ..
Shaping Machine ..
Shaping Machine ..
Feed f
• Feed f is the relative motion of the
workpiece in a direction perpendicular
to the axis of reciprocation of the ram
• Feed is expressed in mm/double stroke
or simply mm/stroke because no cutting
is done in return stroke

13. © rkm2003
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Shaping Machine ..
Shaping Machine ..
Shaping Machine ..
Shaping Machine ..
Depth of Cut d
• Depth of cut d is the thickness of the
material removed in one cut, in mm
• Depth of cut may be given by the tool
head slide or by lifting the table

14. © rkm2003
Machining Time
Machining Time
Machining Time
Machining Time
Width cut in 1 stroke = f
Total width = w
No. of strokes to m/c total surface = w/f
Strokes/mm = N
Time for machining surface is
t = w/(f N) min
f
mm
w
mm L mm

15. © rkm2003
Machining Time
Machining Time
Machining Time
Machining Time
Machining time
min
1000
)
1
(
f
v
m
w
L
N
f
w
t
+
=
=
From cutting speed
)
1
(
1000
1000
)
1
(
m
L
v
N
m
L
N
v
+
=
⇒
+
=
Time for machining w x L surface
min
N
f
w
t =

16. © rkm2003
Material Removal Rate
Material Removal Rate
Material Removal Rate
Material Removal Rate
• Material removal rate (MRR)
MRR = f d L N(1+m) mm3/min
where d is depth of cut in mm
f is feed in mm/stroke;
N is strokes/min
L is length of stroke in mm
m is ratio of return stroke time to
cutting stroke time

17. © rkm2003
Planer
Planer
Planer
Planer

18. © rkm2003
Planer/Planing Machine
Planer/Planing Machine
Planer/Planing Machine
Planer/Planing Machine
Tool head
Bed
Tool head
Tool heads
Housing
Reciprocating
table
Guideways

19. © rkm2003
Types of Planing Machines
Types of Planing Machines
Types of Planing Machines
Types of Planing Machines
• Open Side Planer
• Double Housing Planer
• Edge planer
• Universal planer,
• Pit type planer

20. © rkm2003
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Operating Conditions in a
Planer
Planer
Planer
Planer
• Operating conditions in planer are
similar to Shaping Machine
Cutting Speed: Workpiece reciprocates
cutting time=return time
Cutting Tool: Multiple cutting tools cut
simultaneously
Job: Large size or multiple workpieces

21. © rkm2003
S
S
S
Si
i
i
iz
z
z
ze
e
e
e o
o
o
of
f
f
f S
S
S
Sh
h
h
ha
a
a
ap
p
p
pi
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in
n
n
ng
g
g
g a
a
a
an
n
n
nd
d
d
d P
P
P
Pl
l
l
la
a
a
an
n
n
ni
i
i
in
n
n
ng
g
g
g
Machines
Machines
Machines
Machines
• Largest Size of Workpiece that can
be Machined
L x w x h

22. © rkm2003
D
D
D
Di
i
i
if
f
f
ff
f
f
fe
e
e
er
r
r
re
e
e
en
n
n
nc
c
c
ce
e
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e b
b
b
be
e
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et
t
t
tw
w
w
we
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n
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S
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Sh
h
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a
an
n
n
nd
d
d
d
Planer
Planer
Planer
Planer
• Size of Workpiece
• Movement of Tool and Workpiece
• Construction
• Cutting and Return Speeds
• Number of toolheads

23. © rkm2003
Slotting
Ram
Tool
Base
Tool
holder
Column
Table
Typical Job
Slotter/Slotting Machine
Slot made
by slotting

24. © rkm2003
Example 7.1
Find the machining time required for machining
the surface 600 × 800 mm, on a shaping
machine. Assume, cutting speed as 8 m/min.
The return to cutting time ratio is 1:4, and the
feed is 2 mm/double stroke. The clearance at
each end is 70 mm.
• Solution
Lj = 600 mm, w = 800 mm, v = 8 m/min,
m = ¼, f = 2 mm/stroke, c = 70 mm

25. © rkm2003
Example 7.1 ..
• Given clearance at each end: c=75 mm
• length of stroke:
L = 600 + 2×70 = 740 mm
n
strokes/mi
65
.
8
)
1
(
1000
1000
)
1
(
=
+
=
⇒
+
=
m
L
v
N
m
L
N
v
min
25
.
46
=
=
N
f
w
t
Assume 8.65 strokes/min available
• Machining time for 800 mm width

26. © rkm2003
Example 7.1 ..
• Alternately:
min
25
.
46
2
8
1000
)
25
.
0
1
(
800
740
1000
)
1
(
=
×
×
+
×
×
=
+
=
f
v
m
w
L
t
Assumptions:
Assumptions:
Assumptions:
Assumptions:
N?
N?
N?
N?

27. © rkm2003
Examples
• Example 7.2: Estimate the time required to
machine a cast iron surface 250 mm long and
150 mm wide on a shaper with cutting-to-
return ratio of 3/2. Use a cutting speed of 21
m/min, a feed of 2 mm/stroke and a clearance
of 25 mm. The available ram strokes on the
shaper are: 28, 40, 60 and 90 strokes/min.
Also, determine MRR assuming depth of cut
as 4 mm.
• Solution
• Given data: Lj = 250 mm, f = 2 mm/double
stroke, w = 150 mm,
• c = 25 mm, v = 21 m/ m/min, d = 4 mm
• The cutting-to-return ratio of 3/2 gives m = 2/3

28. © rkm2003
Examples
• Given clearance is 25 mm, hence,
• L = 250 + 2 × 25 = 300 mm.
• We know that (Equation (1))
• SPEED v = NL(1+m)/ 1000 m/min
• From the above equation, we find
number of double strokes N per minute
required as
• N = 42 strokes/min

29. © rkm2003
Examples
• Nearest available ram strokes is 40
strokes/min. Since calculated value is more
than 40, this is chosen. Normally, we should
not exceed the specified cutting speed, as it
will affect the tool life adversely. Hence,
select N = 40 strokes/min.
• With a chosen value of N, we cannot use
Equation (5) for time calculation. Hence,
substituting all the values in Equation (6),
we get
• t = 150 / (40×2)
• = 1.88 minutes