Types of Taper Turning Methods on Lathe Machine

Hello friends, Today we are going to discuss types of taper turning methods on lathe machine.

Before knowing types of taper turning methods on lathe machine, Firstly we have to know parts of lathe machine and different types of taper which has already discussed in previous post.

So without wasting of time let's know types of taper turning methods on lathe machine
.

What is Taper Turning

Cutting the metal on a lathe machine in such a way that, its surface makes an angle with the axis of the metal is called taper turning.
 
The following are the various methods to which taper can represent.

  • According to the top angle of the taper.
  • mm  Per meter (mm / m).
  • According to the diameter of each end of the taper and the length of the taper.
  • By any ratio.

Types of Taper Turning Methods

The following are the different types of taper turning methods on lathe machine.
  • Tailstock Set Over Method
  • Compound Rest Method
  • Taper Turning Attachment Method
  • Form Tool Method 
  • Combining Feeds Method

Tailstock Set Over Method

This taper turning methods is used only for taper turning of small top angles.

Only external tapers can be machined by this method.

In these types of taper turning methods, tailstock is set out of alignment according to the size of the turning taper. 

The clamping mechanism is loosened for offsetting, adjusting the upper part of the tailstock as required, and adjusting screws are tightened which is shown in figure.

types of taper turning methods
Tailstock Set Over Method


This method is also called as Offsetting Tailstock method.

For performing this method ball center type work holding device is used in a tailstock.

The amount of offset is calculated in the following way,

O = (Taper × L)/2000

Where,

0 = Offset, in mm.

Taper = millimeter/meter

L = Length of workpiece in mm


Compound Rest Method

These types of taper turning methods on lathe machine is used for turning small and steep tapers. 

See in figure compound rest method on lathe machine which is described in below.

types of taper turning methods on lathe
Compound Rest Method


In this method firstly compound rest is set at a particular angle corresponding to the center line of the workpiece or a job, It is then locked into this position.

After then cutting tool is set exactly at the center and brought into position by carriage movement. 

The carriage is then locked and then taper turning of the job is done by turning the handle of the compound rest by hand.

Compound rest angle can be calculated by formula,

Tan θ = D-d/2L

θ = tan-1 (D-d/2L)

Where,

D = Larger diameter of the taper
 
d = Smaller diameter of the taper

L = Length of the taper


Taper Turning Attachment Method

The taper turning attachment is an accessory that is provided with the modern lathes.

It is mounted behind the carriage.

It is used for taper turning or boring without tailstock offsetting. 

In this taper turning methods,  job is held in between center or a chuck.

If the job is held between the centers, only the outer taper turning can be done. 

Show in figure taper turning attachment method,

taper turning methods on lathe
Taper Turning Attachment Method


The taper turning attachment consists of a frame that attaches to the rear end of the lathe and a guide bar that is pivoted at the center. 

The guide bar can be swiveled in either side at a 10° angle and it can be clamped to the position by two bolts. 

The taper turning workpiece is mounted parallel to the lathe bed (between the centers as shown in a figure). 

Taper turning attachment forces the tool to move at a fixed angle.


Form Tool Method 

In this types of taper turning methods a straight form tool with a taper angle is set with a taper cutting edge.


Show in figure,


taper turning methods
Form Tool Method


It is given a direct feed on the job so that it creates a definite form on the job.

 

The drawback of this method is that more force is not generated because more area comes in contact between the cutting edge and the workpiece.


Due to the reality of taper turning, this form tool method is only used for short length tapers.



Combining Feeds Method

In such a method, longitudinal and cross feeds are performed simultaneously, so that the tool moves along the diagonal path.

taper turning methods on lathe
Combining Feeds Method


Methods of Measuring Tapers

There are six methods of measuring tapers in precision.
  • By comparing the newly turned taper with a known taper.
  • Using plug gauge for internal taper and ring gauge for the external taper. 
  • Using the taper test gauge.
  • Using gauge blocks, test mandrel.
  • Using sign bars and gauge blocks.
  • Using a micrometer.

So, here I discussed types of taper turning methods on lathe machine and also know it's advantage as well as disadvantage.

I hope you all enjoy these topics.

 
Thank You.

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