To make a tapered stud.

Experiment No. : 02

Aim of the experiment: –

Materials Required: –

Lathe machine
Cutting tools
Outside caliper
Cylindrical mild steel rod of diameter 25 mm

Tools and Equipment

Lathe Machine
Single point cutting tool
Grinding machine
Half round file
Bench vice
Hacksaw
Knurling tool
Outside caliper
Steel rule

Diagram: –

Procedure: –

Following are the steps for various processes:

Facing

The workpiece is held in the headstock using a chuck.

The single-point cutting tool is used by giving it depth of cut in the longitudinal direction and fed in the perpendicular direction.

The tool is moved till the center and the material is removed while the workpiece is rotating.

The depth of cut is gradually increased to obtain a good surface finish.

Drilling

A drill bit is put in the tailstock using a drill chuck.

The workpiece is rotated and the tailstock is moved into the workpiece to get a hole.

Further, countersinking is done such that the tailstock fits in the workpiece nicely.

Turning

The workpiece is rotated and the tool is moved longitudinally along the length of the workpiece, and feed is given in the direction perpendicular to it.

It is done up to the required length and diameter.

The diameter is regularly checked with an outside caliper.

Taper Turning

In taper turning, first, the angle of swiveling of the tool post is calculated using the formula:

\[\color\red{tan⁡\;α\;=\;\dfrac{D−d}{2*l}}\] \[\color\green{where:}\] \[\color\red{D \;=\;}\color\green{ diameter\; of\; the \;larger\; end}\] \[\color\red{d \;= \;}\color\green{diameter \;of\; the\; smaller \;end}\] \[\color\red{l \;=\;}\color\green{ length \;up \;to\; which\; taper\; turning \;is\; required}\] \[\color\red{\alpha\; =\;}\color\green{ angle\; of\; swiveling\; of\; the\; tool \;post}\]

The tool post is rotated by an angle (α) of 2.86°.

The tool is adjusted using the crosshand wheel and the handle on the tool post.

By giving a small depth of cut, the handle of the tool post is rotated in a clockwise direction.

On reaching the other end of the workpiece up to which turning is to be done, the tool is moved back using the cross-hand wheel and again some depth of cut is given, and the tool post is again moved from right to left.

Threading

To set the required TPI (threads per inch), the table is seen, and accordingly alphabets corresponding to it are set on the lathe.

The lead screw and rod are engaged.

(i) To make right-hand thread with 12 TPI (a multiple of 4)

On bringing the tool at the starting point, the clutch is pulled down to move the carriage, and on completion, the clutch is moved up and the tool is taken back using the cross-hand wheel.

The depth of cut applied is regulated by making a mark on the cross-hand wheel.

To make the right-hand thread, the carriage is moved left.

(ii) To make left-hand thread with 10 TPI (not a multiple of 4)

The initial position of the carriage is marked on the gauge with chalk.

The moment the movable part of the handwheel matches with the mark, the clutch is pulled down to move the carriage. In this way, there is no mismatching of threads.

To make a left-hand thread, the carriage is moved right.

Knurling

Knurling is done at the thin section at a distance of 30 mm from where left-hand threads are made. It is done up to 10 mm.

A knurling tool is used, which is compressed on the workpiece while the workpiece is rotated.

Cutting

The threads are made smooth with a little bit of filing using a half-round file while the workpiece is rotating.

The workpiece is then put in a bench vice, and using a hacksaw, the remaining extra part is removed.

Precautions: –

Make sure the entanglement hazards are removed (e.g., loose clothing, jewelry, etc.).
Keep the floor free from obstructions or slip hazards.
The cutting tool should be sharp.
Stop the lathe before taking measurements of any kind.
The start/stop button should be within the easy reach of the operator.

Conclusion: –

To be written by student.

Share this:

Like this: