Taper Turning Methods in Lathe Machine | 4 Basic Types of a Taper Turning Operation

Taper turning methods in lathe machine – An Introduction

A taper turning is the gradual reduction in diameter from one portion of a cylindrical workpiece into another portion as a machining process doing in a lathe machines. Tapers can be external or internal. If a workpiece is confined to the outside, there is an external taper; it has an internal taper if confined to the inside.

In conventional straight turning, the cutting tool travels along a line parallel to the axis of the workpiece, resulting in a completed product that has the same diameter throughout. When cutting a taper, on the other hand, the tool travels at an angle to the axis of the work, resulting in the production of a taper.

For turning a taper, the technique employed is determined by the factors such as degree of the taper, the length of the taper, its placement (internal or external tapers on a turret lathe or lathe machines), and the number of pieces to be turned.

Taper Turning Methods

There are five different types of Taper turning methods in lathe machine

1. Form tool method

2. Tailstock set over method

3. Compound rest method

4. Taper turning attachment method

5. Combining feeds method

It is critical that the cutting tool be precisely centered with respect to the axis of the workpiece when using any of these techniques; otherwise, the workpiece will not be properly conical, and also the rate of taper will fluctuate with each cut.

Form tool method, A Taper Turning Operation

Form Turning is one of the simplest taper turning process in lathe machine to produce short taper. This method is shown in the below taper diagram. To the required angle the form is grounded. The tool is fed perpendicular to the lathe axis, when the workpiece rotates.

Taper Turning By Form Tool Method - Taper Turning

The tool cutting edge length must be greater than the taper length. Since the entire cutting edge removes the metal, it will produce a lot of vibration and hence a large force is required. It is done in slow speed.

Tailstock set over method

Generally, when the angle of taper is very small this taper turning methods in lathe machine will be employed. The workpiece be placed in the live center. Now, the tailstock will be moved in a crosswise, that is perpendicular to the lathe axis by turning the set over method. This process is known as tailstock set over method.

Tailstock Set Over Method - Taper Turning Method

When it comes to offset of tailstock in lathe machine is done for, one thing to consider is the length of the taper. When it comes to the taper, length is important. If the length of the taper varies, the offset will vary as well.

Formula to calculate the tail stock set-over method To calculate Off-set Height
01-Tailstock-Offset-Set-Over-Method-And-Formula-To-Calculate-The-Offset-Distance

01-Tailstock-Set-Over-Method-Tailstock-Offset-Centres

Tail-Stock Offset Centres

Hence here the job is inclined to the required angle. When the workpiece rotates the tool is moved parallel to the lathe axis. So that the taper will be generated on the workpiece.

Compound rest method

Tapering using a swivel compound slide will be the second most straightforward method of creating a taper after that. It can only be used on short tapers. On the compound slide, the angle that has been chosen is half that needed for the taper to be included. It is necessary to use caution in order to prevent bad ending.

Generally short and steep taper will be produced using this taper turning methods in lathe machine. In this method the workpiece will be held in the chuck and it will be rotated about the lathe axis. The compound rest is swiveled to the required angle and then it will be clamped in position.

Compound Rest Method - Taper Turning Methods In Lathe Machine

Then by using the compound rest hand wheel the tool will be fed. Both the internal and external tapers on a turret lathe can be turned using this method. The important feature is that the compound rest in lathe can be swiveled up to 45° on both sides. Only with the help of the hand the tool should be moved.

Even while this technique may provide very accurate results, it has certain limitations owing to the absence of an automated feed and because the length of taper is limited by how far the slide can travel. It is possible to adjust the compound rest base to the necessary angle for taper turning since it is graded in degrees.

It is essential to know the included angle of the taper that will be machined in order to perform the operation. In the case of two crossing straight lines, an included angle is produced by and between them. The angle formed between the taper and the centerline is one-half of the included angle, and it is this angle that the compound rest will be adjusted for when it is assembled.

When using a lathe center with an included angle of 60, the swivel compound rest will be placed at a distance of 30 degrees from parallel to the centerline.

Taper turning attachment method

A Taper Turning Attachment may be used for longer tapers if the tapers are larger in length. In this taper turning methods on lathe machining techniques, a different attachment of lathe machine by using bottom plate or bracket, a taper turning attachment is attached to the rear end of the bed. It has a guide bar which is usually pivoted as its center. The guide bar has the ability to swing and it can be set in any required angle. It has graduations in degrees.

On either side, the guide bar can be swivelled to a maximum angle of 10°. It has a guide block which connects to the rear end of the cross slide and it moves on the guide bar. The binder screw is removed, before connecting the cross slide, hence the cross slide is free from the cross slide screw.

Taper Turning Attachment Method - Taper Turning Method In Lathe Machine

Usually during taper turning gives shapes to the job will be held in the chucks or in the centers. To the required angle the guide bar turned.

Taper Turning Formula

The angle is calculated using the formula, tan (α/2) = (D-d)/2l or tan θ = (D-d)/2l

When the division is given in mm instead of degree, then the angular distance of the guide bar to be tilted is given by

Using the compound rest hand wheel the depth of cut will be given. At an half taper angle the guide will be set. Using this taper turning methods in lathe machine any taper turning method can be done.

01-Taper-Turning-Attachment-Method-Taper-Turning-Attachment-Formula-Taper-Turning-Attachment-Diagram

 

01-Taper-Turning-Attachment-For-External-Taper-And-Internal-Taper-Taper-Turning-Attachment-Diagram

Combining feeds Method

Another more advanced taper turning methodology is taper turning in lathe by combining feeds. Both longitudinal and cross feeds may be engaged concurrently in some lathes, allowing the tool to travel a diagonal course that is the product of the magnitude of the two feeds. The trajectory of the resultant can be adjusted by changing the feed rate by changing the gears given within the apron.

Taper Turning By Combining Feeds - Simultaneous Transverse And Longitudinal Feeds

What is a taper in machining?

It is possible to secure the tool bit into the spindle of a machine tool using a machine taper, which is a fastening mechanism that leverages the laws of friction to do so. This is accomplished by milling a tapered profile into the shank or shaft of the tool bit, which fits into a symmetrical cavity in the spindle of the machine tool to obtain the desired result.

How does a machine taper work?

Work piece pressure forces the machine taper into place, and friction over the whole region of contact keeps the bit in place firmly. Tool bits meant for low duty applications often depend just on friction to hold them in place, but those used in high torque machining may additionally be equipped with a key system or be threaded to further secure them. There are numerous different varieties of machine taper in common use, all of which operate on the same fundamental principles and provide a rapid, easy, and cost-effective way of tool bit locking that is simple and quick to install.

How to choose machine spindle?

When tool bits intended for use in drill presses, milling machines, and lathes are in use, they need a secure locking mechanism to prevent them from being accidentally removed. Because operational bits are subjected to significant quantities of stress, a poorly secured tool bit may destroy a work piece, damage a machine, or cause severe harm to the machine operator if it is not properly secured.

It is possible to produce this locking action with machine tapers by mating a taper-machined shank to a matching groove in the spindle. The friction formed between these two surfaces results in a remarkably secure connection that is capable of sending a significant amount of torque to the tool’s cutting edge. Because of the simplicity of the architecture, bit changes are performed quickly, resulting in increased productivity overall.

Taper designs for light machine usage, such as drill presses, depend on the friction caused by the taper alone to keep the bit locked in place, according to the manufacturer. Machine tapers for heavy load applications may additionally have a thread cut into the two surfaces or a draw bar system to aid in better seating of the machine taper. Several heavy machine taper designs have a critical element that also contributes to their ability to withstand the high torque forces required. In many cases, tapered tool bits include matching grooves in both the bit shank and the spindle that enable a wedge to be used to both securely seat and remove the tool bit.

How many types of taper are there?

Machine Tapers are available in a variety of designs.

Each of the three types of machine taper has its own classification.

1. In accordance with the Class

2. In accordance with Use

3. In accordance with the size

 

In accordance with the Class

There are two varieties of machine taper, which are distinguished by their class.

1. Self-Holding Taper

2. Quick Release Taper

 

Self-Holding Taper

It is important to keep the taper angle smaller than 3° when using this form of taper. In this case, the taper is sufficient to keep the assembled component in place without the need of any additional locking mechanism. It is sometimes referred to as a slow taper.

What is the operation of self-locking tapers?

The cone’s included angle is small in a self-locking holder because of the design. When a tool is put into the spindle nose, friction and other forces are sufficient to keep the tool in place and to transfer the forces and torques. These devices are often referred to as shallow-taper holders.


Quick Release Taper

The taper angle is maintained at or above 18 degrees in this sort of taper.  Because of the high Taper Angle, they need a locking mechanism in order to be clamped properly.  They have a taper ratio of 7:24, which is excellent.


In accordance with Use

There are two varieties of machine taper, each with a different use.

1. Internal Taper

2. External Taper

 Internal Taper

It is referred to as an internal taper when the taper is applied to the inner surfaces of a cylindrical job or workpiece.


External Taper

External Taper is a term used to describe a device that tapers externally on a cylindrical job or work piece.


In accordance with the size

There are many different types of taper based on their size.

1. Morse Taper

2. Metric Taper

3. Jarno Taper

4. Brown and Sharpe Taper

5. Standard Pin Taper

6. Jacobs Taper


Which taper is the most often seen in industry?

Morse Taper

MT 0 to MT 7 Morse Taper is a self-holding type taper that is available in an eight-size range from MT 0. The taper ratio of morse taper is discovered to be 1:10, and its included angle is accessible in three different sizes: 3°, 5/8 inch/foot, and 5/8 inch/foot. Morse taper is mostly utilized in lathe machine drill nose spindle, drill shank, arbor, and other similar applications.

Metric Taper

Metric Taper is a self-holding and quick-releasing type taper that is available in seven different sizes in self-holding and four different sizes in quick-releasing versions. Where MT O to MT 6 sizes are available in self-holding type, while 30°, 40°, 45°, and 50° taper angles are available in quick-releasing type. Metric taper is mostly employed in the nose spindle surfaces of lathe machines. 

Jarno Taper

Jarno taper is also a self-holding form of taper that is available in 20 sizes ranging from 01 to 20 sizes in length. Jarno taper has a taper ratio of 1:20, and its included angle is offered in 0.6 inch per foot of length. It is mostly utilized in die marking machines, as previously stated.

Brown and Sharpe Taper

In terms of size, the Brown and Sharpe taper is available in both self-holding and quick-releasing versions, with 18 sizes available in self-holding and 09 sizes available in quick-releasing. Whereas BS 1 to BS 18 sizes are available in self-holding type, and sizes 4 to 12 are available in quick-releasing type. In the case of the Jarno Taper, the taper ratio is 1:20, and the included angle of the BS 10 is 0.5161 inch/foot.

In addition, all other forms of tapers, including angle tapers, are 1/2 inch per foot. The spindle and arbor of a milling machine are both made of Brown and Sharpe taper.

Pin Taper

A self-holding pin taper is a form of pin taper that is often used. The taper ratio of a conventional pin taper is 1:50 in metric and 1:48 in British units of measurement. It has a 1/4 inch/foot angle included. Pin taper standard, as used in clamp devices, tapered pin, and so on.

Jacobs Taper:

Jacobs taper is primarily utilized in drill press chucks, arbors, and other similar applications.

Is the Jacobs taper the same as the Morse taper, or are they different?

In the drilling industry, Jacobs Tapers are virtually solely utilized for Drill Chuck Mounting. A broad range of tooling incorporates Morse Tapers, including drill bits, reamers, end mill holders, drill chuck arbors, collet centers and lathe centers, among other things. Brown and Sharpe tapers may be found on comparable tooling, however they are more often seen on older tools and machines than on newer ones.

FAQs

What is the meaning of taper turning?

Taper turning is a turning technique in which the cutting tool travels at an angle to the axis of the workpiece, resulting in a tapered form in the workpiece after the cutting tool has been moved. A tapered piece is one in which the diameter of the workpiece varies evenly from one end to the other while it is being turned. The workpiece may be tapered from either the interior or the exterior of the workpiece.

What operation is the gradual reduction in diameter from one part of a cylindrical workpiece to another part?

Taper turning is a lathe machining technique that involves gradually decreasing the diameter of a cylindrical workpiece from one end to the other. External or internal tapers are available.

What are the different types of tapers?

Taper is defined as a consistent variation in diameter that results in a wedge or conical shape. The three most popular techniques of taper turning on the lathe are: the offset tailstock set-over method, the compound rest method, and the taper attachment method.

The function of taper turning process is to ____

1. Reduce the diameter of a work piece along its length

2. Reduce the diameter by removing material about an axis offset from the axis of work piece

3. Remove the material from end surface of a work piece

4. All of the above

Answer:

All of the above

What are the limitations of the form tool taper turning method?

It is limited to cutting short tapers and requires knowledge of either the included angle or centerline angle.

Which of the following is not the method of taper turning?

1. Guide Block

2. Sliding Block

3. Guide Bar

4. Carrier

Answer:

Carrier

Which of the following methods does not involve taper turning?

All of the five methods are examples of taper turning techniques. The compound rest in Lathe technique, and also the taper attachment technique, may be used to turn both internal and external taper, while the tailstock offset method is only utilized for exterior tapers.

What is the meaning of tailstock set over?

It is common practice to use taper turning operation on lathe machine when the angle of taper is very small. It is necessary to put the workpiece in the live center. By rotating the set over technique, the tailstock will be moved in a transverse direction, which is perpendicular to the lathe axis, at this point.

Example Problem:

Calculate the tail stock set over for turning a taper on a job such that its two diameters are 80mm and 50mm. Total length of the job is 300mm and the length of tapered portion is 200mm only

Solution:

Taper angle, tan (α/2) = (D-d)/2l and another formulae to calculate offset distance is h = (L (D-d)) / (2*l)

= (300 (80 – 50) ) / (2*200) = 22.5 mm

What is the best way to specify a taper?

The taper is defined by the diameter of the workpiece throughout its length. The amount of taper defined by the ratio of the difference in the diameters of the taper to the length of the taper is known as the amount of taper. Examples of taper diameters are 1:4, or 0.5: 4 etc.

What is the meaning of taper in drawing?

A draft of a foundry pattern, as provided by the foundry.

What is the taper turning formula and how does it work?

The set over length may be calculated using the following formula: S=L*(D-d)/2l, where l denotes the taper length, L is the total job length, d denotes the smaller diameter, and D denotes the bigger diameter.

Which technique is utilized only for internal taper? For turning internal tapers the suitable method is__________

1. Tail stock offset

2. Taper attachment

3. Form tool

4. Compound rest

Answer:

Swivelling the Compound Rest in lathe allows you to turn the taper. This technique is exclusively used for turning internal tapers, not for turning external tapers. Half cone angle (α) is used in this technique to swivel the compound rest, which means that it is rotated in a horizontal plane by half of the conical angle.

Internal or external taper on a turret lathe can be turned by

1.Face turning attachment

2. Taper turning attachment

3. Sliding attachment

4. Morse taper attachment

5. Offsetting tailstock

Answer:

Taper Turning attachment

What is the formula for converting taper to degrees?

Divide the decimal inch by 12 to get the decimal foot taper per foot by dividing the decimal inch by 12. For example, 1.2/12 = 0.1 is a fraction. By calculating the arc tangent of the taper, you may convert the decimal foot taper to a degree angle in degrees. On calculators, the arc tangent is sometimes denoted by the symbols atan or tan-1.

Formula for the Taper Calculator. T = (dl – ds) / L.
Angle of taper in degrees = atan (0.5 x T)

Diameter that is larger (dl), Diameter is smaller (ds), and The length of a workpiece (L).

What is the best way to test a taper?

An instrument for measuring taper is taper ring gauge is employed.

Describe the method of generation of a long and small taper in a centre lathe?

1. Form tool method; 2. Tailstock set over method; 3. Compound rest in lathe; 4. Taper turning attachment method are the four popular methods of generation to produce long and small taper turning in a centre lathe.

In a lathe, taper turning means to produce a_____ surface by gradually decreasing the value of diameter from a cylindrical work piece.

a) conical surface
b) flat surface
c) both conical and flat surface
d) none of the mentioned

Answer:

Conical surface

What are the operations performed on Lathe other than turning? What are the types of Turning Operations?

Besides turning, a lathe may do the following machining operations:

Lathe Machine types of operations:

01-Basic-Turning-Operation-Perform-In-A-Lathe-Machines

Facing – Feeding the tool radially into the rotational piece to produce a level surface. The facing tool’s movement direction is determined by the machining process, cutting edge shape, tool orientation, and workpiece geometry (either hollow part nor solid). Roughing is done from the outside to centre, and finishing is done from the inside to outside.

Taper turning – It is a cylindrical turning method in which the resultant diameter changes continuously. Conical shafts are made this way.

Contouring – It is possible to contour the turned section by using contour turning instead of turning.

Form turning – It imparts a shape to the work by stabbing the tool radially into it.

Chamfering – The tool’s cutting edge is used to carve an angle into the cylinder’s corner.

Parting off – The tool is radially fed into the rotational work to cut off the end of the component. This action is called parting.

Threading – A pointed tool is fed at a high effective feed rate over the outer surface of the spinning workpart, forming threads in the cylinder. The lead screw and feed gear system generate the precise feed necessary for thread cutting. This is done by connecting the main spindle to the feed drive motor.

Boring — A single-point tool is fed along the inner diameter of an existing hole in the component.

Drilling – Drilling on a lathe requires inserting the drill into the rotational work along its axis. Reaming is similar.

Knurling – It is not machining since no material is cut. A regular crosshatched pattern is created by forging metal.

 

Contents

%d bloggers like this: