Diploma (Mechanical)
Workshop Practice-2 For 4th Semester
MACHINE SHOP RULES
1. Students are not permitted to work without a Supervisor in the Machine Shop. An
approved paid employee must be present at all times.
2. All who enter the shop must sign-in at the office.
3. When working in the shop two people must be present at all times. “Buddy’s” are
not to touch machinery controls.
4. Safety glasses must be worn at all times. Tinted or Sunglasses are not to be used
in the shop.
5. No sandals or open-toe shoes. Work boots or street shoes ONLY.
6. Do not wear loose clothed or jewelry. Tie back long hair.
7. Material Safety Data Sheets must be supplied on materials not listed in shop MSDS
book before work can begin.
8. Dispose of waste according to the MSDS sheets and posted signs.
9. No part washing in the sinks. Sinks are for hand washing only.
10. Do not lay rags on lathe or mill.
11. Do not enter the shop under the influence of drugs or alcohol.
12. All metal scraps and cuttings are to be disposed of in the proper recycling drum.
Do not put trash or metals of unknown composition into the recycling drum,
separate plastics.
13. Do not throw anything away unless you are certain it is unusable. If in doubt ask the
Supervisor.
14. Do no enter material storage area without permission.
15. Accidents and/or machine problems must be reported immediately to the
Supervisor. The Lab Director and faculty will be notified to determine possible
disciplinary action when failure to report a problem promptly, lying, or false
statements take place.
16. All students must complete a training course to be allowed to operate the
equipment. Untrained students will be limited, as determined by the Shop
Supervisor
17. Students should never talk on a cell phone while operating equipment.
18. The Supervisor must check all machine setups before machine operation begins.
19. Do not use compressed air for cleaning. Refer to cleaning guide in shop manual.
20. No arguing or horseplay in the shop.
21. Work Studies should set an example for shop workers. Therefore rule breaking
and/or repeated improper shop practice is reason for dismissal and disciplinary
action.
22. No Eating or Drinking in the shop.
23. All tools must be signed out (this includes cutting tools) for use outside of the shop
area. You must get the shop Supervisor’s approval before leaving the shop with a
tool. All tools must be returned and documented.
24. Students who do not return tools will be subject to university disciplinary action.
25. A work order is required to build parts at the machine shop.
General Safety Guidelines
1. Do not attempt to remove foreign objects from the eye or body, report to the
student health service for medical treatment. If chemicals get in the eye(s), wash
eye(s) for 15 minutes in an open flow of water before proceeding for medical
treatment.
2. Do not use compressed air to blow dirt or chips from machinery to avoid
scattering chips. Never use compressed air guns to clean clothing, hair, or aim
the gun at another person.
3. Machines must be shut off when cleaning, repairing, or oiling.
4. Keep rags away from moving or rotating machinery.
5. Do not wear ties, loose clothing, jewelry, gloves, etc. around moving or rotating
machinery. Long hair must be tied back or covered to keep it away from moving
machinery. Hand protection in the form of suitable gloves should be used for
handling hot objects, glass or sharp edged items. DO not wear gloves while
operating machinery *Exception: under special circumstances, with the approval
of the machine shop supervisor, thin latex skin tight (correct size) gloves may be
worn if required as PPE.
6. Wear appropriate clothing for the job (i.e. do not wear short sleeve shirts or short
pants when welding).
7. Do not work in the shop if you are tired or in a hurry – this almost always ruins
the work, and often results in injury.
8. Never indulge in horseplay in the shop areas.
9. All machines must be operated with all required guards and shields in place.
10. A brush, hook, or special tool is preferred for removal of chips, shavings, etc.
from the work area. Never use your hands to clean cuttings – they are sharp!
11. Keep your fingers clear of the point of operation of machines by using special
tools or devices, such as, push sticks, hooks, pliers, etc. Never use a rag near
moving machinery.
12. A hard hammer should not be used to strike a hardened tool or any machine
part. Use a soft-faced hammer.
13. Keep the floor around machines clean, dry and free from trip hazards. Do not
allow chips to accumulate.
14. Think through the entire job before starting. Ask for help if you have
questions.
15. Before starting a machine, always check it for correct setup and always check to
see if machine is clear by operating it manually, if possible.
16. No drinking or eating in shop area. Do not bring food or snacks into the shop.
17. Do not attempt to operate equipment under the influence of drugs or alcohol.
18. If you have not worked with a particular material before, check the materials
safety data sheets book for any specific precautions to be taken while working
with the material. Also, ask the shop personnel before cutting any unusual
material.
19. Heavy sanding and grinding should only be done in well-ventilated areas,
preferably on the patio. Painting on the patio only – make sure that the doors to
the shop are closed.
20. Follow all appropriate precautions when working with solvents, paints, adhesives
or other chemicals. Use appropriate protective equipment.
21. Check the power cords and plugs on portable tools before using them.
22. Always store oily rags in an approved metal container.
23.
Only one person may operate a machine. The “Buddy” should watch and never
activate or touch controls.
TITLE: DEMONSTRATION OF OPERATIONS ON CENTRE LATHE
APPARATUS: lathe machine and mild steel rod.
OBJECTIVE: To study the various operations such as turning, step turning, facing,
boring, taper turning, knurling, grooving, threading of center lathe.
THEORY: A product is made up of many components which are manufactured by
various manufacturing processes such as casting, forging, welding; machining etc
depends on the application and cost of that particular component. In the machining
process various operations comes like turning, step turning, facing, boring, taper
turning, knurling, grooving, threading. All these operations can be done on center lathe
hence center lathe is one of the importance type of machines. In this practical we are
going to study the operations which are mentioned above. Lathe is a machine tool
which rotates the work piece on its axis to perform various operations such as cutting,
sanding, knurling, drilling or deformation with tools that are applied to the work piece to
create an object which has symmetry about an axis of rotation. Examples of objects that
can be produced on a lathe include candlestick holders, gun barrels, sticks, table legs,
bowls, baseball bats, musical instruments (especially woodwind instruments),
crankshafts and camshafts.
Parts of lathe and their function
Bed: Almost all lathes have a horizontal beam is called as bed. It has guide ways on it
for sliding and supporting tail stock and carriage.
Head stock: At one end of the bed (almost always the left, as the operator faces the
lathe) is a headstock. It contains drive mechanism with necessary speed change
arrangement to achieve different speeds. It also has chuck which is used to hold the
job.
Tail stock: It is places opposite to headstock. It can move along guide ways. Its main
applications are to hold long jobs to avoid vibrations and excessive deformation and for
drilling axial holes in the work piece it can also hold the tools such as drill, reamer, tap
to do the operations like drilling, reaming etc.
Carriage: It is located between head stock and tail stock. It can be moved in
longitudinal direction and can be fixed at any position. Carriage has following parts
a. Saddle: Its base portion, located across lathe bed and carries cross slide and tool
post, it can be moved longitudinally along the bed.
b. Apron: it is attached to saddle and appears as hanging on front side. It consists of
gears for motion transmission.
C: Cross slide: it is mounted on top of the saddle and acts as support to compound
rest
D: Compound rest: It is mounted on cross slide and it consists of swivel and top slide.
The tool post is mounted on top slide.
E: Tool-post: it is used to hold the tool position the tool as per the requirement.
Fig.: Schematic Illustration of center lathe
Various Lathe operations
Turning: It is the process of removing the material from extended surface of rotating
work piece. So it is the process by which a piece of material (wood, metal, plastic, or
stone) is rotated and a cutting tool is traversed along 2 axes of motion to produce
precise diameters and depths
Step Turning: It is the process of obtaining different diameters on a work piece along
the length by adjusting depth of the tool.
Fig: Step Turning
Taper Turning: It is the process of giving the angle to the work piece with the help of
compound slide.
Fig: Taper turning
Boring: It is the machining of internal cylindrical forms (generating) a) by mounting work
piece to the spindle via a chuck or faceplate b) by mounting work piece onto the cross
slide and placing cutting tool into the chuck.
Fig: Boring operation
Knurling: The cutting of a serrated pattern onto the surface of a part to use as A hand
grip using a special purpose knurling tool.
Fig. Knurling Tool
Threading: It is the process of producing the helical V grooves on the surface
with the help of lead screw.
Fig: Threading Process.
Facing
It is the process of removing the material from the end surface or face of work piece.
Fig: Facing
Grooving: It is the process of producing V shape cyclical groove on the surface, the
tool has similar V shape as required to produce on work piece.
Fig. Grooving
CONCLUSION:
Hence we have studied various operations such as turning, step turning, facing, boring,
taper turning, knurling, grooving, and threading which are performed on center lathe.
REFERENCES:
1. Elements of Workshop Technology (Vols. 1 and II) by Hajra chaudhary
TITLE: DEMONSTRATION OF OPERATIONS ON DRILLING MACHINES
APPARATUS: Drilling machine and mild steel rod.
OBJECTIVE: To study the various operations on drilling machines such as drilling,
reaming, spot facing, counter boring.
THEORY: Holes in the work piece are necessary for many purposes such as fastening
the object with nuts and bolts, Screws, for fixing assembly purpose So it is necessary to
make holes in the work piece. So the Drilling is a process of making a hole in the blank
work piece, or enlarging the existing hole. The Machine which is used foe this purpose
is called as drilling machine. It consist of spindle which is rotated by the motor and
transmitting mechanism, The spindle in turn rotates the drilling tool called as drill, as drill
is press fitted into the spindle. Drill is fed into work by feed mechanism. The work piece
is fixed on the table, as the drill fed into the work piece; the hole is created by removing
material in the form of chips. All the components are supported by frame. Cutting fluid
is commonly used to cool the drill bit, increase tool life, increase speeds and
feeds, increase the surface finish, and aid in ejecting chips.
Fig: Drilling machine
Parts of Drilling machine and their function
Base: base is the lowest horizontal part which supports the entire structure of drilling
machine. It is made up of cast iron because cast iron absorbs vibrations. So the
vibrations transmitted to foundation get reduced.
Work table: It is mounted on column which supports the work. Generally its has two
types of motions. a. It can swing about column. b. it can move up and down. This
facilitates the positioning of work piece while drilling.
Spindle: It is a hollow portion which is provided with rotary motion spindle imparts this
rotator motion to drill.
Head: It consist of drive mechanism and feed mechanism.
Operations Performed on the drilling machine
Drilling: It is the process of making a hole in blank work piece with tool known as drill.
Fig: Drilling
Reaming: It is process of finishing and sizing of drilled hole with the help of tool called
as reamer.
Fig: Reaming
Boring: It is process of enlarging the already existing hole to meet the required Size
and finish.
Fig: Boring
Spot facing: It is the process of machining a flat circular surface around a hole
to provide a seat for a bolt head nut or washer.
Fig: Spot facing
Counter boring: It is the process of cylindrically enlarging the face of existing hole.
Fig: counter boring
CONCLUSION:
Hence we studied various operations such as drilling, reaming, spot facing, counter
boring which are performed on Drilling machine.
REFERENCES:
1. Elements of Workshop Technology (Vols. 1 and II) by Hajra chaudhary