Which type of taper turning method is recommended for chamfering operation and is suitable for short taper turning operation? 

Explanation:

Taper Turning Methods

• Taper turning is a machining process on a lathe where the diameter of a cylindrical workpiece is gradually reduced from one end to the other, forming a conical shape. This process is used to produce tapered components such as pins, spindles, and shafts.

Methods of Taper Turning:

• There are several methods to achieve taper turning on a lathe. These include the tailstock offset method, taper turning attachment, form tool, and the compound rest method. Each method has its own advantages and is suitable for different types of taper turning operations.

By form tool:

• Using a form tool for taper turning is recommended for chamfering operations and is particularly suitable for short taper turning operations. A form tool is a single-point cutting tool that is ground to the shape of the desired taper. When the form tool is fed into the workpiece, it cuts the taper in a single pass, making it an efficient method for producing short tapers and chamfers. This method is ideal for operations where high precision and consistency are required.

Taper Turning by Swivelling the Compound Rest

• This method is used for turning internal tapers only.
• In this method the compound rest is swiveled i.e. rotated in a horizontal plane by half cone angle (α). The workpiece is rotated as usual but instead of using the carriage to traverse the tool the tool is moved forward by the compound rest slide handwheel. Since the compound rest has been swiveled to an inclined position to the longitudinal axis of the lathe the tool moves at an angle to the longitudinal axis of the lathe generating a conical surface accurately.
• The compound rest can easily be swiveled or rotated and clamped at any desired angle.
• This method is limited to turn a short but steep taper because of the limited movement of the crossslide. The compound rest can be swiveled at 45° on either side of the lathe axis enabling it to turn a steep taper.

The following methods are used for taper turning on the lathe:

• By swiveling the compound rest
• By offsetting tailstock
• By using a taper turning attachment
• By using a form tool

Taper turning means to produce a conical surface by a gradual reduction in diameter from a cylindrical workpiece.

Taper turning by attachment

This attachment is provided on a few modern lathes. Here the job is held parallel to the axis and the tool moves at an angle. The movement of the tool is guided by the attachment.

Tailstock offset

• When the tailstock is offset for taper turning the centerline of the tailstock is still parallel to the lathe bed as shown in the figure
• The tailstock offset method is generally used to cut a taper when no taper attachment is available
• The amount that the tailstock may be offset is limited
• This method will not permit steep tapers to be turned or standard tapers to be turned on the end of a long piece of work.