kathikā

The following text is an English translation of THIS technical chapter in Hindi.

CHAPTER 11

SHAPING MACHINE

INTRODUCTION

A shaping machine is a reciprocating type of machine tool mainly used for forming flat surfaces with the help of a single point cutting tool of an appropriate measurement and size.

These flat surfaces can be as follows –

1. Horizontal surface
2. Vertical surface
3. Angular surface
4. Slot groove and Key-way
5. Machining spline, ratchet, and gear with the help of an induction device.

11.1 CLASSIFICATION OF SHAPING MACHINES

Shaping machines are classified as follows on the basis of the specifications of their design and objectives –

1. According to the mechanism of the reciprocating motion of ram –

1. Crank type
2. Gear type
3. Hydraulic type

2. According to the design of the working table –

1. Standard type
2. Universal type

3. According to the travel of the ram –

1. Horizontal type
2. Vertical type
3. Traveling Head type

4. According to the cutting stroke –

1. Push type
2. Draw type

11.2 DIFFERENT TYPES OF SHAPING MACHINES

The different types of shaping machine are as follows –

1. Crank Type – This machine uses a crank mechanism in which the rotational speed of the bull gear or big gear is converted into the reciprocating motion of the ram.

Figure 11.1 – Mechanical Movement of Ram in Shaping Machine

2. Gear Type – This machine uses a rack and pinion to attain the reciprocating motion of the ram. The rack teeth cut right below the rack are meshed with the spur gear. The pinion is in mesh with the drive of the rack, which is held by a gear train. . The direction and movement of the working of the machine depends on the gear train and number of gears. This type of shaping machine is not used commonly.
3. Hydraulic Type – This machine uses hydraulic power to attain the reciprocating motion of the ram. Oil pressed with the help of pump, at high pressure enters the operating cylinder with a piston arrangement. The head of the piston rod is connected to the ram. The high-pressed oil pushes the piston first towards one side, and then towards another side. Consequently, this produces a reciprocating motion of the piston. This motion is transferred to the ram.

Figure 11.2 – Hydraulic Pressed Ram Drive

Advantages of Hydraulic Shaping Machine

The advantages of hydraulic shaping machine are as follows –

1. It works without making any noise.
2. It works smoothly without any shocks/jolts.
3. It can attain a constant cutting speed.
4. The ram can operate at many different speeds.
5. It has the ability to take heavy cuts.
6. Emergency equipment is not required, thus, it requires low investment capital.
7. Standard Type – In a standard type machine, the working table feed is attained only in two directions – horizontal and vertical.
8. Universal Type – In addition to the two directions of the standard type, the working table of this shaping machine can be moved parallel to the axis of the ram-way. And we can also bend the upper part of the table, first perpendicular to the vertical position of the axis, and second, to the horizontal position. The job set on the working table can be adjusted in different planes. This type of machine is considered most useful for different types of work, and in the tool room. Thus, it is called a universal shaping machine.
9. Horizontal Type – It is mainly used for developing flat surfaces. The tool holding device in a horizontal shaping machine moves in a reciprocating motion along the horizontal axis.
10. Vertical Type – The tool holding device in a vertical shaping machine moves in a reciprocating motion along the vertical axis. In some types of this machine, adjustment is possible at an angle of 10° in the vertical position of the ram. This type of shaping machine can function through crank, rack, screw, hydraulic power. The working table can move in a  perpendicular or rotational motion along its  length wise direction. The tools used by this machine are completely different from the tools used in a horizontal shaping machine. Machining of internal and external gears is possible with the help of indexing arrangement of the rotary working table. Special type of vertical shaping machine which are used  for machining internal key-slots is called a key-seater. This machine is very convenient for machining internal surfaces, constructing slots and  grooves and key-ways.
11. Traveling Head type – In a traveling head type of shaping machine, the reciprocating ram also moves crosswise for providing the necessary feed to the tool. If the job is heavy, then it is extremely difficult to set it on the table of a standard shaping machine and slide it in front of the tool. Such type of heavy job is placed on the base of the traveling head shaping machine, and feed is obtained through the reciprocating of the ram.
12. Push Type – This is a commonly used shaping machine in which the material is cut during the forward stroke of the ram.
13. Draw Type – In a draw type shaping machine, the cutting stroke is obtained when the ram moves towards the column of the machine. In other words, the ram sets the job in a fixed direction of the standard shaping machine. The ram receives support from the arm above it. This maintains rigidity and the tool is not distorted. The cutting pressure is active towards the column. Consequently, this reduces the load on the cross-rail and other bearings, and allows us to make deeper cuts. This shaping machine does not face any problems of vibrations.

11.3 MAIN PARTS OF A SHAPING MACHINE

The main parts of a shaping machine are as follows –

1. Body – The body of a shaping machine is made of cast iron in order to tolerate vibrations. It contains the main drive, gear box, and quick return reciprocating mechanism.
2. Base – It is made of cast iron and bolted rigidly to support the full weight of the machine.
3. Table – This is box-shaped, with t-slots cut on its upper surface and corners for holding the job or vice. The table can be moved up or down with the help of a travel lifting drive spindle. A cross-feed screw is used for moving it in the horizontal direction.
4. Cross Rail – The cross-rail is fixed in front of the column on the guide-way. It is mounted with standing surfaces/planes that have two parallel guide-ways perpendicular to the ram. The working table can move up-and-down to set jobs of different measurements. We can slide the cross-rail up-and-down the vertical surface of the column by turning the elevating screw. A horizontal cross-feed screw is fixed in the middle of the cross-rail, which is parallel to the upper guide-way of the cross-rail.. The working table can be slided across with the help of cross rail.
5. Ram – This is a semi-circular part of the shaping machine fitted above the body. The ram moves in a reciprocating motion using the quick return mechanism. A tool head is fitted on one end. The length of the stroke is set according to the length of the job that has to be machined using the lead screw of the ram.
6. Saddle – A saddle is fitted on the cross-rail which is tightly holding the working table upright. We can turn the cross-feed screw manually or with any tool to move the saddle cross-wise and slide the working table towards the side.
7. Tool Head – The tool is tightly clamped in the tool head. This helps in providing a standing angular feed motion to the tool. It allows the tool to loosen automatically during the return stroke. The clapper block tightly fits in the clapper box during the forward cutting stroke. The tool head can move up-and-down using the feed screw handle to measure the depth of cut. We can move this using a calibrated adapter plate for machining angular surfaces.

Figure 11.3 – Tool Head

11.4 SPECIFICATIONS OF SHAPING MACHINE

The size of a shaping machine is determined on the basis of the maximum length of its stroke and cut. Generally, this is from 175 to 900 mm. The length of the stroke refers to the size of the cube that can be machined on  shaping machine. Additionally, we also pay attention to the following main points –

1. Input power
2. Type of drive
3. Weight of machine
4. Required floor surface area
5. Ratio of cutting stroke to return stroke
6. Number and amount of feeds

11.5 QUICK RETURN MECHANISM

The process of metal cutting in a shaping machine takes place when the tool moves forward. This is called the cutting stroke. When the tool returns to its original position again even without any cutting process, it is called an idle stroke, and the time taken during this stroke is called idle time. If the tool returns quickly, we can save time and thereby increase the production rate. The mechanism used for this purpose is called the quick-return mechanism.

The description of the principle of the quick-return mechanism is given below.

Figure 11.4 – Principle of Quick Return Mechanism

The bull gear rotates by receiving power from the pinion. The driving pin is in a fixed position with the sliding block. The sliding block slides in the slotting link. The lower part of the slotting link is connected to the pivot, and its upper part is connected to the ram by the compensating link. As soon as the bull gear receives power from the pinion and rotates, the slotting link starts oscillating on the pivot. The oscillating motion of the ram is converted into reciprocating motion by the compensating link. The driving pin covers a longer arc during the idle stroke and smaller arc during the return stroke. The path of the return stroke is shorter than the forward stroke.

Stroke Length

The slotted link moves quickly during the return stroke, and at the same time, the ram covers the distance equal to the stroke. The average values of the forward stroke path and return stroke path are 216° and 144° respectively. In other words, the ram moves comparatively faster during the return stroke compared to the cutting stroke. Consequently, this reduces the idle time. The ratio  of cutting time to return time is generally 2:1, whereas its practical limit is upto 3:2.

Stroke Length Adjustment

The stroke length is equal to the return stroke and cutting stroke. The radius can be adjusted.. For this, the position of the crank slide is changed to turn the bull gear. In this way,  the radius increases thereby increasing the stroke length.

Figure 11.5 – Stroke Length Adjustment

If we increase the swelling limit of the slotted link, the length of the stroke arm will increase. Its rotation depends upon the actual radius  between the driving pin and convexity of center of the bull gear.  The radial lead screw is turned inwards and outwards consecutively for increasing or decreasing the radius. The length that has to be machined is set according to the stroke length.

While working, we can change the stroke length by changing the radial distance between the bull gear axis and driving pin.

11.6 FEED MECHANISM

A shaping machine has two basic movements related to the job – speed and feed. Both the motions are in mutually perpendicular directions. In a shaping machine, feed is the distance traveled by the job towards the side of the ram near the cutting tool during each forward stroke. Whereas in vertical machining, feed is the forward distance traveled below the tool during the cutting stroke. The feed of a shaping machine is set by the automatic feed mechanism in such a way that the working table and job  move during the return stroke of the ram. This protects the tool from getting damaged. The feed rate depends on the following main factors –

1. Material that has to be machined
2. Condition of shaping machine to perform work
3. Type of cut (rough/finish)
4. Surface finish
5. Type of cutting tool

Figure 11.6 – Automatic Feed Mechanism

The Automatic Feed Mechanism of a shaping machine functions in the following manner –

The cross-feed and screw rod are attached to the working table. The pole arm and crank-wheel are attached to the connecting rod. As soon as the crank-wheel turns, the pole arm starts reciprocating across the cross-feed screw. The pole is pressed on the ratchet wheel by a spring. The ratchet wheel is indexed in one direction due to the straight edges of the pole. When we turn the pole by 180° and engage it, we obtain indexing in the opposite direction. When the cross-feed screw rotates, the working table moves automatically during each return stroke of the ram. We can set the desired amount of feed on the crank-wheel scale. The number of teeth that are indexed depends upon the distance between the crank-wheel axis and adjustable block. We pull the pole upwards while giving the feed manually, and place it back while removing the pin. During the return stroke of the ram, we turn the cross-feed screw rod by its handle and set the feed manually.

11.7 WORK SUPPORTING AND HOLDING DEVICES FOR SHAPING MACHINE

During machining, the workpiece should be held rigidly otherwise it can become loose and cause damage to itself, the tool  and the operator. The top and sides of the working table of the shaping machine have -T-slots. The workpiece is held in these -T-slots with the help of different types of clamps. These clamps are as follows –

1. Machine Vice – Two main types of machine vices are used in a shaping machine –

• Plain Machine Vice – This is the simplest type of strong vice which has one or two screws for operating the jaw. Therefore, it is useful for stock removal and a very heavy job.

Figure 11.7 – Plain Machine Vice

• Swiveling Vice – This is the most standard type of vice used on a shaping machine. Its base is marked with degrees for moving the vice body on the horizontal surface according to the desired angle. A swiveling vice is very useful for beveling the head of a job.

Figure 11.8 – Swiveling Vice

2. Strap Clamps – A strap clamp is used for clamping the workpiece directly/straight on the machine table. The straps are available in different sizes and types, and they are used along with T-bolts and nuts. These bolts have a T-shaped head.

Figure 11.9 – Strap Clamps

Figure 11.10 – T-Bolt

The  T-shaped head fits in the slots of the machine table and holds a good grip.

Figure 11.11 – Strap Clamp Joints

3. Parallel Strips – When the height of the workpiece is lesser than the height of the vice jaw, we use purely grinded square and rectangular parallel steel strips, which are called parallel strips. These are used for lifting the workpiece and placing it above the vice jaw or parallel to the vice bottom. These are only used on machined surfaces.

Figure 11.12 – Parallel Strips

4. Degree Parallels – These are steel strips grinded in angular surfaces. It is used for constructing angular surfaces without turning the tool head.

Figure 11.13 – Degree Parallels

5. V-Block – These are V-shaped blocks that are used for support during clamping a round job.

Figure 11.14 – V-Block

6. Angle Plate – An angle plate is made of cast iron and is used for holding L-shaped jobs. Both the arms of the angle plate are smoothened. Thereafter, we make an angle of 90° between them. One arm is clamped on the working table with the help of the T-bolt, and the work piece is clamped on the other arm.

Figure 11.15 – Angle Plate

7. Toe Dogs and Poppets – They are used for holding small repetitive workpieces and the upper surface of very big work pieces ( which does not have any type of holes on their edges).

Figure 11.16 – Toe Dogs and Poppets

Figure 11.17 – Toe Dogs and Poppets

8. Shaping Dividing Center – This special attachment is used for constructing equidistant slots and spline on a round job, and in special circumstances, for gear cutting on the shaping machine.

Figure 11.18 – Shaping Dividing Center

11.8 SHAPING TOOLS

The tools of a shaping machine are single point cutting tools. These are of the following types –

1. Solid type
2. Bit type
3. Tipped type

Figure 11.19

. The basic cutting operation of a shaping machine tool is similar to cutting tool of a lathe machine. The tool is grinded on left hand cutting or right hand cutting according to the feed direction, and its angle depends upon the material and size of the job. However, some standard sizes of the tool are specified according to some standard work. These are as follows –

1. Straight Roughing Tool – This tool is used in the beginning of the operation when material removal is more important than surface finishing. A straight roughing tool can be used like a finishing tool for increasing the radius of its nose.

Figure 11.20 – Straight Roughing Tool

2. Cranked Roughing Tool – This type of tool has two cutting edges. One is used for machining horizontal surfaces and the other for machining vertical surfaces. Other features of this type of tool are similar to the straight roughing tool. During machining a vertical surface, there should be sufficient gap between the bed/vice and tool so that the tool  does not get stuck.

Figure 11.21 – Cranked Roughing Tool

3. Round Nose Tool – This tool is considered useful for both, right hand cutting and left hand cutting. This tool can shape horizontal and curved surfaces. It can also be used for shaping a light cut.

Figure 11.22 – Round Nose Tool

4. Grooving / Slotting Tool – This tool can also be used for shaping a narrow slot. Width of the tool is set according to the slot size. We can obtain only light cuts using this tool.

Figure 11.23 – Grooving / Slotting Tool

5. Offset Shaping Tool – This tool can give both types of feeding , horizontal and vertical. It is considered the best tool for step machining.

Figure 11.24 – Offset Shaping Tool

6. Special Tool –. On many occasions, the exact size of the job cannot be obtained through the standard working tools. Thus, a new tool is constructed by improving these old tools. An example of this type of tool, the T-slot tool, is shown in the figure.

Figure 11.25 – T-Slot Tool

Figure 11.26 – Special Tool

7. Tool Shank – Tool shanks are available in both, square and rectangular shapes.

Table 11.1 – Square Shank

Table 11.2 – Rectangular Shank

11.9 CUTTNG SPEED AND CUTTING TIME

Cutting Speed – The distance covered by the tip of the tool of a shaping machine in one minute is called its cutting speed. It is always denoted in meter/minute. Cutting seed is also known as surface speed or peripheral speed. It is selected on the basis of the material of the tool that has to be machined and the depth of cut. The cutting speed required for different materials is recommended in the table below –

Table 11.3

S. No.	Material to be Shaped by HSS	Cutting Speed(meter/minute)
1.	Aluminum	70 – 100
2.	Brass	35 – 60
3.	Grey Cast Iron	30 – 35
4.	Mild Steel	25 – 40
5.	Mild Steel, Carbon Steel	27 – 30
6.	Plastic	20 – 30

The cutting speed of a shaping machine depends upon the ratio of the speed of the cutting stroke and return stroke of the ram.

Let’s assume that this ratio is m, then,

Cutting Speed (v) = NL (1+m)/1000

where, L = Stroke Length

N = Number of cutting strokes per minute, or number of cycles per minute

m = Speed of ram in return stroke/ Speed of ram in cutting stroke

N = 1000v/L(1+m)

Here, we obtain a return stroke after each cutting stroke. This means that one revolution of bull wheel includes one cutting and one return stroke. Thus, N also denotes the number of revolutions/minute of  bull wheel. Thus, one return stroke with one cutting stroke is also called one cycle. The time taken during one cycle is important because the time taken to shape/machine the given surface depends upon the cycle time. Cutting Time – The time taken to shape the surface depends on the feed (f) and cycle time (t). Therefore, a  less feed means more time for machining, and a  more feed means less time for machining. To calculate the cutting time, we will first determine the total number of cycles (c) required for shaping the width (w), and then multiply this by the cycle time (t).

Figure 11.27 – Cutting Time

Total Number of Cycles = w/f

Where, w is the job width plus the clearance on both sides, and f is feed per stroke. Since t is the amount of time taken for each cycle, thus, total machining time = t X c (minute).

Example 1: The stroke length of a shaping machine is 200 mm/minute, number of cycles is 40, and the ratio of return stroke time to cutting stroke time is 2:3. Calculate the cutting speed.

Solution: It is given –

N = 40 = Number of cycles

L  = 200 mm/minute

m = 2/3

Cutting Speed   = NL (1+m)/1000

= 40 X 200(1+2/3)/1000 = 40 X 200 X 5 / 1000 X 3

Answer                                = 13.33 meter/minute

Example 2: The cutting speed of a shaping machine is 9 meter/minute, ratio of return stroke to cutting stroke time is 1:4, feed is 3 mm. Calculate the time taken for completing a cut of 500 X 700 mm plate. Clearance value on each end is 70 mm.

Solution:             Total stroke length = 500 + 70 + 70 = 640 mm

Cutting Time = 640 X 60 / 1000 X 9 = 4.266 second

Return Time/Cutting Time = ¼

Thus,                     Return Time = 4.266 X ¼ = 1.0665 second

Total Time for Completing a Double Stroke = 4.266 + 1.0665 = 5.333 second

Total Number of Double Strokes for Completing the Cut = 750/3 = 250

Total Time for Completing the Cut = 5.333 X 250 / 6

Answer = 22 minute 13 seconds

Feed – Feed is the relative activity that takes place perpendicular to the direction of the reciprocating motion of the tool and job. Feed is expressed in mm. In shaping, feed is always given during the return stroke, when the tool is not cutting the material. Feed is selected according to the thickness and type of material.

Depth of Cut – ‘Depth of Cut’ is the thickness of material that is removed in each cut.

PRACTICE QUESTIONS

œ Choose the correct option for the following questions.

1. In which component does the ram of a shaping machine slides in?

(a) Dovetail groove	(b) Rack and pinion
(c) On the bed	(d) Slot

Answer) A

2. In shaping machine work, if the stroke length is 250 mm, number of double stroke per minute is 27, return to cutting time is 2:3, what is the cutting speed?

(a) 1120 m/min	(b) 112 m/min
(c) 11.2 m/min	(d) 1.12 m/min

Answer) C

3. A shaping machine is identified as per –

(a) Motor H.P.	(b) Table size
(c) Stroke length	(d) Maximum size of tool

Answer) C

4. What is used for aligning the position on the table of a shaping machine?

(a) T-bolt	(b) Dial test indicator
(c) Screw jack	(d) Straight edge

Answer) B

5. Answer the following questions based on the figure below –

• Moves up-and-down and cross-wise for giving feed.

Answer) D

• Moves to-and-fro by the quick return mechanism.

Answer) B

• It has the main drive of the shaping machine.

Answer) A

• It is the base of the shaping machine.

Answer) C

6. The formula for cutting speed (v) of a shaping machine is –

(a) NL (m-1) / 100	(b) NL (1-m) / 100
(c) NL (1+m) / 1000	(d) NL (m-1) / 1000

Answer) C

7. The stroke length of a shaping machine is useful for which adjustment?

(a) Sliding block	(b) Fulcrum pin
(c) Radial lead screw	(d) Compensating link

Answer) C

8. In a shaping machine, feed is the distance –

(a) forward and return, distance traveled across by the table in front of the machine in both strokes	(b) distance traveled by ram in forward stroke
(c) distance traveled across by the table in front of the machine in return stroke	(d) distance traveled by ram in return stroke

Answer) C

9. Cutting speed of the tool in a mechanical shaping machine is –

(a) Maximum during middle of cutting stroke	(b) Maximum during beginning of cutting stroke
(c) Maximum during end of cutting stroke	(d) Minimum during complete cutting stroke

Answer) A

10. Generally, the ratio of forward and return stroke of a shaping machine is –

(a) 3:2	(b) 2:3
(c) 1:2	(d) 2:1

Answer) A

11. In a shaping machine, the objective of quick return motion is –

(a) reduce idle time during shaping	(b) to set the job quickly
(c) provide slow speed during forward stroke	(d) achieve good finishing on job

Answer) A

12. The ram of a shaping machine reciprocates by the –

(a) Bull gear	(b) Radial lead screw
(c) Compensating link	(d) Sliding block

Answer) C

13. In a shaping machine, , when the driving pin of the bull gear rotates with equal speed, the slotted link stops quickly during the return stroke due to –

(a) Longer length of travel of pin	(b) Shorter length of travel of pin
(c) Equal length of travel of pin	(d) No load on ram

Answer) B

14. In a shaping machine, the following is made for feed mechanism –

(a) Rocker arm	(b) Pole and ratchet
(c) Bull gear	(d) Cross-rail

Answer) B

15. In a shaping machine, if the cross-feed screw pitch is 42mm and the pole is set to pass through 2 teeth out of the 60 teeth of the ratchet wheel, then what is the cross-feed/stroke?

(a) 16 mm/stroke	(b) 1.3 mm/stroke
(c) 1.2 mm/stroke	(d) 1.4 mm/stroke

Answer) D

16. In shaping machine tools, which angle allows the chips to flow?

(a) Side  rake	(b) Front clearance
(c) Top  rake	(d) Side clearance

Answer) C

17. Compared to the cutting tools of lathe, the cutting tools of a shaping machine should have the following angle –

(a) Low clearance and high  rake	(b) Low  rake and high clearance
(c) Low clearance and low  rake	(d) High  rake and high clearance

Answer) C

18. In a shaping machine, a high speed steel tool is used in the following way –

(a) Same speed of carbide tools	(b) Higher speed than carbon steel
(c) Lesser speed than carbon steel	(d) Equal speed to carbon steel tool

Answer) B

19. This is a device for setting the depth and position of cut while holding the cutting tool –

(a) Clapper block	(b) Tool post
(c) Vertical slide	(d) Swivel base

Answer) B

20. Which of the following work holding device is given priority for shaping the key-way in a shaft/cylindrical job?

(a) Angle plate	(b) Dividing head
(c) V block	(d) Shaping machine vice

Answer) C

21. Answer the following questions on the basis of the figure –

• Identify the clapper block in the shaping machine tool head.

Answer) B

• Identify the clapper box in the shaping machine tool head.

Answer) A

• Identify the tool post in the shaping machine tool head.

Answer) A

• Identify the vertical slide in the shaping machine tool head.

Answer) D

22. Following is useful while shaping a round job –

(a) V Block	(b) Angle Plate
(c) Toe Dogs	(d) Stepped Block

Answer) A

23. Following is useful for holding a symmetrical and asymmetrical shaped job on the table while shaping –

(a)  Stepped Block	(b) Angle Plate
(c) Machine Vice	(d) Toe Dogs

Answer) B

24. Which of the following type of shaping machine cuts the material in return stroke?

(a) Standard Shaping Machine	(b) Universal Shaping Machine
(c) Push Type Shaping Machine	(d) Draw Type Shaping Machine

Answer) D

œ State Whether  True or  False.

1. The table of a shaping machine can be operated in three directions.

Answer) False

2. The shaping machine tool is lifted during the cutting stroke.

Answer) False

3. In a shaping machine, the tool move across the work whereas the table remains fixed.

Answer) True

4. A horizontal shaping machine is also called a slotter.

Answer) False

5. The use of bull gear in a shaping machine increases the speed ratio.

Answer) False

6. Whitworth quick return mechanism is also known as Slotted Link mechanism.

Answer) True

7. Rotate the pole by 180° for changing the direction of feed.

Answer) True

œ Match the following.

1. Match the following parts of the shaping machine with the figure.

(A) Tool Post

(B) Tool Head Slide

(C) Hinge Pin

(D) Feed Screw Handle

(E) It can slide up-and-down

Answer) A4, B3, C1, D2, E3

2. Match the following.

(A) Bull Gear	1) It helps to lift the tool during the return stroke.
(B) Rocker Arm	2) It moves by a pinion.
(C) Clapper Box	3) It is mounted on the face of the gear.
	4) It is pivoted on the bottom of the base.

Answer) A-1; B-3,4; C-1

œ Answer the following questions in brief.

1. In a shaping machine, flat and angular surfaces are constructed by the reciprocating motion of the cutting tool on the surface that has to be machined. Mention its four functions.

Answer)               (i) To construct horizontal, vertical and angular surfaces.

(ii) To cut slots, key-ways and grooves.

(iii) To machine contour surfaces.

(iv) To cut splines, ratchets and gear teeth.

2. How is the size of a shaping machine determined?

Answer) The size of a shaping machine is determined by the maximum length of the stroke of its ram.

3. Mention three functions of the bull gear in a shaping machine.

Answer) (i) Adjust the stroke of ram (ii) Increase power, (iii) Operate other controls

4. The stroke length of a shaping machine is set to 300 mm, number of strokes per minute are 30, ratio of return to cutting stroke is 2:3. Calculate the cutting speed.

Answer) Cutting Speed                 = N X L (1+  m) / 1000

= 30 X 300 (1+ 2/3) / 1000 = 15 meter/ minute

5. What do you understand by the feed of a shaping machine?

Answer) Feed is the distance traveled by the table across the machine during the return stroke.

6. What is the objective of quick return motion in a shaping machine?Answer) The objective of quick return motion in a shaping machine is to reduce the idle time during return stroke.

Notes:

1. Please check grammar while forming/translating sentences.

For Eg: What does the ram of the shaping machine slide in?

But the correct sentence is “In which component does the ram of a shaping machine slides in?

For Eg: The reciprocating motion of the ram holding tool of a horizontal shaping machine is in horizontal axis.

But the correct sentence is “The tool holding device in a horizontal shaping machine moves in a reciprocating motion along the horizontal axis.”

1. The sentence formation is not correct in many sentences.

For eg: It has a heavy load carrying capacity.

But the correct sentence is “It has the ability to take heavy cuts.”

1. While translation, please take care to not change the meaning of the sentence.

For Eg: The objective of quick return motion in a shaping machine is to reduce wastage of time during shaping.

But the correct sentence is “The objective of quick return motion in a shaping machine is to reduce  the idle time during return stroke.”

For Eg: In a shaping machine, when the bull gear rotates with speed equal to driving pin.

But the correct sentence is “In a shaping machine, when the driving pin of the bull gear rotates with equal speed”

1. Rack should be replaced by rake.