1-Lect One_engineering Practices

8/2/2019 1-Lect One_engineering Practices

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ENGINEERING PRACTICES-I

An Introduction to the Course:

COURSE CODE : IM-121

CREDIT HOURS : 1-1 COURSE CONSISTS OF THE FOLLOWING MAIN TOPICS:

1. THEORYa) Carpentry and Sawing

b) Metals and Metal Working

c) Forging

d) Drilling & Grinding Machinese) Welding

f) Electrical Shop

2. PRACTICALa) Woodworking (Carpentry)

b) Bench Fitting Work

c) Welding (Gas & Elect Arc Welding)

ASSESMENT OF SESSION WORK:1. Quizzes : 2 - 3

2. Assignments : 1

3. OHT : 1

4. END TERM : 1 ( Theory & Practical)


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SAFETY PRECAUTIONS

1. Introduction to Safety Precautions

2. Causes of Accidents

3. General Safety Precautions

4. Shop Floor safety


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INTRODUCTION TO SAFETY PRECAUTIONS

1. Working safely is the first essential of an operator

2. An operator should learn the safe-way of doingthings, and he must also know the unsafe waytoo.

3. The safe way is the correct way and efficient wayof doing things.

4. Safety is an attitude for learning and practicingthe safe habits.

5. A good and safe operator is one who is safetyconscious always, using safe and accepted

practices.


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CAUSES OF ACCIDENTS

Generally, the causes of accidents (things that can lead toaccidents) can be listed as follows:

1. Operating without authority2. In operative safety devices3. Operating at unsafe speeds4. Using unsafe equipment

5. Working at unsafe position or posture6. Operating without using safety protective devices7. Working in noisy or bad environment8. Defective working conditions, i.e. slippery, corroded,

cracked, etc.9. Unsafe lighting and ventilation

10. Unsafe dress (improper or loose garment)11. Not interested (distracted in work)12. Operating/ working carelessly, not concentrating13. Operating/ working with lack of discipline14. Operating with lack of skill or knowledge.


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GENERAL SAFETY PRECAUTIONSwhich you must take in order to avoid accidents..

1. Before operating a machine, all protective guards should be in theirproper places.

2. Machines should be operated by authorized operators only.

3. A machine should not be stopped hands or body.

4. Before staring a machine, operator should check that the work andtools are clamped securely.

5. Shop floor should be free from oil, clear of metal chips or curls orwaste pieces.

6. Operator should leave the machine only when it comes to a fullstop.

7. Machines and switches should be operated by the same operator.

8. Operator should not lean towards the machine once it is running.9. Operator should concentrate on the work and not talk un-

necessarily while operating the machine.

10. Operator should have sufficient light and ventilation for performinga particular operation.

cont. .


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GENERAL SAFETY PRECAUTIONSwhich you must take in order to avoid accidents..

11. No one should disturb the operator while he is operating a machine.12. Tools are not to be used for any purpose other than those they are

designed for, i.e. spanners re not hammers and file tangs are notdrifts.

13. Files are not to be used without file handles.

14. Tools should be in good state (of repair/ condition).

15. Sharp end of scribers must always point downwards.16. Chipping must always point towards screen (away from other

workers).

17. Goggles must always be worn when there is a danger of flyingparticles of chippings, etc.

18. Always use a brush for cleaning chips, burrs and not to flick with

cloth.19. Do not rub fingers, hands along work edges/ faces.

20. All accidents, major or minor, should be reported to supervisors/instructors/ superiors, etc.


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SHOP FLOOR SAFETY

1. The shop floor should be free from oil, liquid of anykind or grease to avoid slipping hazard.

2. Shop floor should be clean and clear at all times toavoid accidents.

3. The tools and work should be kept in position aftercompletion of each work, to avoid toe or foot injury.

4. Store materials and finished products should beproperly handled by proper handling equipment toavoid tripping

5. Tools should be kept in safe position when not in use.


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CARPENTARY

AND

SAWING


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SAFETY PRECAUTIONS IN WOOD WORKING

1. Safety is to be observed and safety precautions are to be taken

while handling and using all sorts of tools or working onmachines in the workshop.

2. Although working with carpentry tools is comparatively less riskythan working with metal cutting tools, but still we need to observeall possible precautions to avoid injuries to self and others.

3. While working with wood working machinery, like cutting saws,electrical planers, we must ensure that all machinery should beeffectively guarded with covers, cages or guards.

4. All mechanical fed machines must have cutting heads, feed units,pulleys and belts completely covered.

5. The cutting edges of saws are very sharp, and other cutting toolshave sharp cutting edges ---- must be handled carefully.


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DRAWING AND PLANNING

1. Before making a part, you should prepare a PRODUCT PLAN.

2. A product plan has all the information needed to make a product:a) A working drawing of the part

b) A bill of materials

c) List of steps to make the part, in proper sequence.

WHAT IS A WORKING DRAWING?

1. A working drawing gives all information needed to make the part.

2. It must show the following kinds of information:-

a) Shape of the part of the product

b) The size of the productc) Location and sizes of holes, if any

d) Kind of material

e) Kind of finish


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MEASURING AND LAYING-OUT

You need to be careful in measuring and

laying out to make a good product.

The most common MEASURING TOOLS are:-

1. BENCH RULE:

a) It is a wooden rule with brassprotection rule cap at each end.

b) It may be 12, 24 or 36 long.

c) One side of the rule is marked in 1/16in & other side 1/8 in.

d) It is used for measuring small stockand marking short distances.

2. STEEL TAPE:

a) The steel tape has a hook on the endwhich can be placed over the edge orend of the stock.

b) Tape bends easily, so easy to measurecurves

c) Comes in 6, 8, 10 12, 16 & even 50& 100.


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SQUARING TOOLS:

A square is used t make a layout line on thestock at right angle to an edge. Common layout/

squaring tools are:

1. TRY SQUARE:

a) Used for squaring, measuring andtesting.

b) Also used for checking ends, edgesand surfaces for squareness.

2. FRAMING SQUARE:

a) It is also called a Carpenters square.b) It is used to check for squareness &

for squaring lines across wide stock.


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3. SLIDING T-BEVEL:

a) It is used in the same manner as the

other squares.

b) The blade can also be adjusted toany desired angle in the handle.

c) A protector is commonly used to setthe angle

d) Used to measure or layout any angle

between 0o and 180o.

4. MEASURING & MARKING WIDTH:

There are two methods:

a) Marking gauge is used for up to 6

width.b) Wider widths are laid out with rule

and straight edge.
http://images.google.com.pk/imgres?imgurl=http://images.meredith.com/wood/images/2006/02/p_casegauge1.jpg&imgrefurl=http://www.woodmagazine.com/woodworking-plans/homemade-tools/a-case-for-marking-gauges/&usg=__74R2cPy614dxg2tMIFV42P9qYTs=&h=368&w=400&sz=20&hl=en&start=16&tbnid=RhONAqioqPfKTM:&tbnh=114&tbnw=124&prev=/images%3Fq%3Dmarking%2Bgauge%26gbv%3D2%26ndsp%3D20%26hl%3Den%26sa%3DN


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CUTTING OR SEPARATING WOOD

The most common wood cutting tools

is a HAND SAW.

The most common SAWS are:

1. CROSS CUT SAW:

a) Used for cutting across the grain of thewood.

b) It cuts on the push stroke

c) Blade lengths are from 20 to 26 length

d) Has 8 12 teeth/ inch (tpi)

e) Has pointed teeth.

2. RIP SAW:

a) Used for cutting a board along the grain.b) Cuts on the push stroke

c) Length of the rip-saw blade is 26

d) Has 5 6 teeth /inch

e) Has CHISEL shape teeth.
http://images.google.com.pk/imgres?imgurl=http://chestofbooks.com/crafts/machinery/Shop-Practice-V1/images/Hand-Saws-Rip-Saw-And-Crosscut-Saw-100110.png&imgrefurl=http://chestofbooks.com/crafts/machinery/Shop-Practice-V1/Hand-Saws-Rip-Saw-And-Crosscut-Saw.html&usg=__Ul_DwRkhcxLHFQj7Amxwpcxq7gM=&h=552&w=443&sz=7&hl=en&start=138&um=1&tbnid=ECgrfc5gXjKqBM:&tbnh=133&tbnw=107&prev=/images%3Fq%3Dcross%2Bcut%2Bsaw%26ndsp%3D20%26hl%3Den%26sa%3DN%26start%3D120%26um%3D1


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DEFINITIONS

1. PITCH: Number of teeth per inch

2. KERF: A saw cuts a kerf whichis wider than the bladethickness.

3. SET: Alternate teeth of ahandsaw are bent in the

opposite directions.

The bending of the teeth arecalled set.


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CUTTING OR SEPARATING WOOD

3. TENNON SAW OR BACK SAW:a) It is a very fine toothed cross cut saw.

b) It has 14 t.p.i.

c) Blade is very thin and back is re-enforced by a band of steel.

d) It makes a very smooth cut.

e) Used when an exact cut is needed.

f) Normally used for cutting joints andsquaring stock.

4. COMPASS SAW & COPING SAWa) Large curves are cut with compass saw

b) Used to cut curves and circles

c) Different types of blades are useddepending on the type of wood being

cut. (Coping saw)d) When using a vise for holding the job,

point teeth of the saw away from thehandle, and when using bench, teethshould point towards the handle.

(Coping saw)

Compass saw

Coping Saw


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PLANNING, SQUARING AND SMOOTHING (OR

SHAPING)

Planning is the process of making a

smooth, flat surface by removingstock.

Thin shavings or chips are removedwith the cutting edge tool.

HAND PLANES are used for this

purpose Planes are made in booth wood and

metal

TYPES OF PLANES:

1. JACK PLANE:

a) Is an all round plane to smooth andlevel the surface of boards & all roughplanning.

b) Also planes the edges of boards

c) It is about 14 in. long (380 mm)


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PLANNING, SQUARING AND SMOOTHING (ORSHAPING)

2. TRYING PLANE

a) Almost 22 in length (560 mm) longb) Largest plane used

c) Straight planning and leveling

d) Length varies from 560 600 mm

3. SMOOTHING PLANE:

a) It is a finishing plane

b) Also used for working on end grain

c) Metal : 10 in long (250 mm)

d) Wooden : 8 in long (200 mm)

4. BLOCK PLANE:a) Used on small boards

b) It is usually 4 to 5 ins. Long

c) Good for planning end grain (shallow bladeangles)

d) Normally used with one hand only.
http://images.google.com.pk/imgres?imgurl=http://www.highlandwoodworking.com/ProductImages/handplanes/031206.jpg&imgrefurl=http://www.highlandwoodworking.com/ibexluthiersconvexsolefingerplane25mm.aspx%3Fnext&usg=__t3HdBslQSQN95Y9w1I_L4os0RhY=&h=300&w=300&sz=11&hl=en&start=2&itbs=1&tbnid=NUX2cyCCZJuGLM:&tbnh=116&tbnw=116&prev=/images%3Fq%3Dblock%2Bplane%26gbv%3D2%26hl%3Den%26sa%3DGhttp://images.google.com.pk/imgres?imgurl=http://chestofbooks.com/home-improvement/woodworking/Cabinet-Making/images/Fig-13-Smoothing-Plane.jpg&imgrefurl=http://chestofbooks.com/home-improvement/woodworking/Cabinet-Making/Jack-Plane.html&usg=__29tHo_-6LtE5yAtiKYqdfZ-JapM=&h=232&w=296&sz=8&hl=en&start=13&itbs=1&tbnid=lPijyaNP0OJFnM:&tbnh=91&tbnw=116&prev=/images%3Fq%3Dtrying%2Bplane%26gbv%3D2%26hl%3Den%26sa%3DG


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PARTS OF A PLANE

(PLANE IRON)

HEEL

KNOB

TOEPLANE IRON

(Blade)
http://images.google.com.pk/imgres?imgurl=http://ecx.images-amazon.com/images/I/31T0wEOLQ2L._SL500_AA280_.jpg&imgrefurl=http://www.amazon.com/Footprint-280410-Replacement-Smooth-Models/dp/B000VJF6TU&usg=__JRQ1x8GN0fxte1KG8qJTlu57uRI=&h=280&w=280&sz=5&hl=en&start=18&itbs=1&tbnid=HD6TS9jMuP3uRM:&tbnh=114&tbnw=114&prev=/images%3Fq%3Djack%2Bplane%2BBLADE%26gbv%3D2%26hl%3Den%26sa%3DG


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SHAPPING TOOLS

1. CHISELS:

a) The chisel is an edge cutting tool. Thecutting action of a chisel is the sameas a plane iron.

b) The size of the chisel is its width(Lengths are standard)

c) Chisels are used to cut joints and toremove extra material from stock.

d) Sizes range from 1/8 in to 2 in.

e) Blade of chisel is ground to 30o angle.

To do fine work, the edge should besharp.
http://images.google.com.pk/imgres?imgurl=http://www.toolstation.com/images/library/stock/webbig/21364.jpg&imgrefurl=http://www.toolstation.com/shop/Clearance/Hand%2BTools/d50/sd2680&usg=__nKKEhdJRgJa-sy8YSSosO95R6ww=&h=500&w=500&sz=32&hl=en&start=5&itbs=1&tbnid=nQXojifmv1PsPM:&tbnh=130&tbnw=130&prev=/images%3Fq%3Dwood%2Bchisels%26gbv%3D2%26hl%3Den%26sa%3DG


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SHAPPING TOOLS

TYPES OF CHISELS:

1. FIRMER CHISEL:

a) Used for light mortising, choppingout, parting and other general type ofwork.

b) Sizes come in widths of 3 50 mm.

2. MORTISE CHISEL:

a) Stouter than firmer chisels.

b) Can withstand heavy mallet blows

c) Used for making large and deepmortises

d) Sizes: width from 2 25mm


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SHAPPING TOOLS

TYPES OF CHISELS:

4. BEVEL EDGE CHISEL:

a) Beveled on each side

b) Ideal dove tailing and workingin corners

c) Sizes: widths from 3 50 mm

5. PAIRING CHISEL:

a) Are in fact long beveled-edge

chisels.b) Used for making large and

deep mortises

c) Sizes: width from 25 35mm
http://images.toolspot.co.uk/Carpentry/Irwin%20Marples%20M750%20Bevel%20Edge%20Chisels%20Splitproof%20Two%20Component%20Handle.jpg


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SHAPPING TOOLS

GOUGES:Gouges may be defined as curved

chisels and are mainly used for shaping,carving and scribing.

TYPES OF GOUGES:1. INSIDE GROUND GOUGES:

Used for scribing

2. OUTSIDE GROUND GOUGES:

Used for shaping and carving


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FIXING TOOLS

These are hammers, mallets,

screw-drivers, nails punches, etc.

1. HAMMERS are of two types:

a) BALL-PEEN HAMMER: Usuallyused in the shop.

b) CLAW HAMMER: For out sidefixing.

2. MALLETS: Heads are generallymade of beech wood.

3. SCREW DRIVERS:

a) Ordinary Screw Driver

b) Ratchet Screw Driver

c) Spiral or Pump Screw Driver

BALL-PEENCLAW HAMMER
http://images.google.com.pk/imgres?imgurl=http://www.mytoolstore.com.au/images/4807spr.jpg&imgrefurl=http://www.mytoolstore.com.au/boker-spiral-ratchet-screwdriver-p-1706.html&usg=__Eog-TDoQhodVe6k3y-QPCbhCogc=&h=375&w=500&sz=13&hl=en&start=48&itbs=1&tbnid=MR5JMNzirNUJGM:&tbnh=98&tbnw=130&prev=/images%3Fq%3Drachet%2Bscrew%2Bdriver%26gbv%3D2%26ndsp%3D20%26hl%3Den%26sa%3DN%26start%3D40


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END OF THIS LECTURE

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1-Lect One_engineering Practices