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FACULTY OF MECHANICAL & AUTOMOTIVE ENGINEERING TECHNOLOGY BMM 1811 MECHANICAL LABORATORY 1

BENCHWORK Fitting Process Laboratory Date

5 APRIL 2021

Submission Date

16 APRIL 2021

Lecturer

16 APRIL 2021

1) JP/PJP

2) 3)

Learning objectives By the end of semester, students should be able to: • Identify various types of hand tools. • Describe the application of various types of hand tools. • Use various types of hand tools properly within safe practice. • Determine the correct tools for threading process. • Apply the knowledge to produce bench work project.

Members MUHAMMAD ADLI BIN MD NOOR

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ID

Section

MA20125

01

Signature Adli

REV.04

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MUHAMMAD ASYRAFF BIN SHARUDIN

MA20131

01

Asyraf

MOHAMAD AMZAR HAKIMI BIN YUSUF

MA20133

01

Amzar

MUHAMMAD HANNES DANIEL BIN MISWAN

MA20145

01

Hannes

MOHD NURUDDIN SYAKIRIN BIN MA20147 01 Nuruddin NORDIN 1. Purpose To study the uses of common hand tools and appreciate the importance of fitting work in the trade. 2. Machine: Drilling machine 3. Tools & Equipment: Bench vise, Marking out table, hammer, Files, Center punch, ,Steel ruler, File card, Scriber, Vernier high gauge, Vernier caliper, L square, Hacksaw, Angle plate, Dividers, Reamer 6H7, Hand tap set M6, Chisel etc. 4. Material: Mild Steel plate 102mm x 52mm (approximately 6 mm in thickness). Refer to drawing given (Drg. No. 1811-0001). 5. Basic Theory The workbench is the craftsman’s headquarters, where operations involving the use of hand tools such as sawing, filing, chiseling and marking out are appropriately carried out. In this section, students will be introduced to the basic complement of hand tools commonly used in all branches of mechanical technology such as bench vise, files, hacksaw and center punch, and scriber. Bench Vise The bench vise is used to help grip the workpiece for filing, hack sawing, chiseling and bending light metal. The bench vice mainly consist of a fixed jaw, movable jaw and jaw plates (Figure 1). Most bench vises have hardened insert jaws that are sharply serrated and will dig into finished workpieces enough to mar them beyond repair. Hence, soft jaws made of copper, other soft metals or wood are often slip over the vise jaws to protect the workpiece’s finished surface. Figure 1: Bench Vise Bench vise should be mounted correctly on the workbench where the top of the vise jaws should be at elbow height. Inappropriately mounted bench vises causes poor workpiece to be produced.

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Figure 1: Bench Vise Bench vise should be mounted correctly on the workbench where the top of the vise jaws should be at elbow height. Inappropriately mounted bench vises causes poor workpiece to be produced. Filing Filing involves the small scale removal of material from a surface, corner, or hole, including the removal of burrs. Files are usually made of hardened steel and are available in a variety of cross sections such as flat, round, half round, square and triangle (Figure 3).They are commonly manufactured in four different cuts: single, double, curved tooth and rasp. Each cut design has its own purpose. For instance, rasp files are frequently used with wood while curved tooth files are used with soft materials such as aluminium, brass, plastic, or lead. Files also vary in their coarseness; rough, coarse, bastard, second cut, smooth and dead smooth.

Figure 2: Basic components of a file

Figure 3: Various file cross sections

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In order to produce a flat surface, work should be held firmly in the vise with the minimum amount of projecting and with the surface to be filed to be truly horizontal. The right hand pushes and presses while the left hand only presses with the same amount of pressure. Pressure should only be applied during forward stroke only. The Figure 4 below illustrates the proper technique of Hand filing. Success in filing flat is dependant on hand control to keep the file horizontal throughout its stroke and an equal distribution of pressure. In order to test the surface of work during filing, a straightedge can be placed on it. If rays of light can be seen between the two surfaces of the workpiece and the straightedge, then the surface of the workpiece is not flat.

Figure 4: Hand movement during filing Care should be taken while filing to avoid dulling and breakage of its teeth. Teeth on files will break if the tools lie on top of each other and if too much pressure is applied while filing. Dulling of teeth is caused by the filing of hard materials or by filing too fast. A good rule of thumb is the harder the material, the slower the strokes should be; the softer the material, the coarser the file should be. Sawing The hacksaw is one of the more frequently used hand tools. It consists of the frame, the handle and the saw blade (Figure 5). The spacing of the teeth on a hand hacksaw blade is called the pitch. Standard pitches are 14, 18, 24 and 32 teeth per inch, with the 18-pitch blade used as a general-purpose blade. The hardness and thickness of a workpiece determine to a great extent which pitch blade to use. Generally, a coarse tooth blade should be use on soft materials and a fine tooth blade on harder materials. There are a few points that should be noted in order to obtain maximum performance from a blade:-  Make long steady strokes using the full length of the blade. • Maintained sufficient pressure on the forward stroke to keep the teeth cutting. Too much pressure on the saw blade will cause its teeth to dull. • Do not apply any pressure at the blade during return stroke since this will also dull the teeth • The sawing speed should be at the rate of 40~60 strokes per minute. Cutting stroke that is too fast causes friction that will overheat the teeth and dull it.

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Figure 5: Main components of a hacksaw A cut on a workpiece should be started with only light cutting pressure, with the thumb or fingers on one hand acting as a guide for the blade. A small veenotch could also be filed onto the material to help start a blade. In order to avoid vibration and chatter, ensure that the cutting is done close to the vise jaws. Center Punch The centre punch is used when circular dot marks are required. When job has been marked out it is usual to follow along the lines with small dot marks in case the line becomes obliterated. It is also used to mark the centre point of drilling holes for the purpose of giving starts to the drill and to mark the centre of circles to provide a point for placing the leg of the dividers to scribe the circle. Various types of center punch are illustrated as below.

Figure 6: Types of center punch Scriber The scriber is a round steel piece of about 150mm to 300mm long and 3mmto 5mm in diameter. Its one end is sharp and pointed and the other end is also sharp but bent. The bent end is used to scratch lines in places where the straight end cannot reach.

Figure 7: Scriber

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6. General planning the job a. Study the drawing and lab sheet given. Ensure you understand them and know exactly what has to be done to the workpeice. i.e. Has any excess material to be left on sizes for grinding or hardening? b. Check material for machining allowance. c. Plan out sequence of operation. Ask yourself the following questions: i. Can any operations be combined? ii. Can any operation be eliminated? iii.Is sequence the best possible? d. Select method of working-the simplest is usually the best. Ensure it will hold the workpiece securely. e. Select tools – the selection to the operations to be perform, the material and the type of machine you are operating. 7. Project Methodology: a. File the workpiece into square shape with dimension 100mm x 50mm. b. Use “L” square and appropriate file to obtain flat surface (180°)

c. Select another side of the work piece and file as previous step to obtain a flat 90° surface.

d. Use L square to check the surfaces, if rays of light cannot be viewed between the work piece and the L square, i.e. the surface is already flat. Make sure that the workpiece is filed to the correct dimension. e. Select the flat surface as the reference surface for marking process. f. Mark the workpiece using vernier high gauge and angle plate on the marking table. g. Create the rounded curve using divider based on given dimension.

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h. In order to make the cross section point line more visible, use the center punch. This to ensure the measurement is consistently correct. i. Begin the removing process by cutting the unused material using hacksaw, drilling & chisel. j.

Smooth the edges of the workpiece through filing.

k. Perform the drilling work for tap holes according to the steps described below:i. Center drill ii. Drill size Ø5mm thru. iii. Tap M6 thru. l. Do the drilling work for through ream hole accordingly as below:i. Center drill ii. Drill bit size Ø5.8 mm iii.Reamer 6H7. m. Saw the workpiece (3 lines) until get the correct dimension given. n. Do the finishing work. Remove all sharp edges and rusty. o. Punch your matrix number on the workpiece using lettering & numbering punch. 8. Measurement Final dimensions of the workpiece. Sketch the part (your workpiece) drawing and write the dimensions achieved.

9.Discussion a. Sketch the flowchart for fitting process.

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Start

Mild steel plate 102 mm

Cutting

Forming

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Heat Treatmen

Beveling

Pickling

end

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b. Disscuss the importance of the following proper steps for fitting process  An accident can be avoid during the experiment either in individual or group task.  We will get the accuracy of the dimension of all products,Beside that,we can adjust the auto mode when the drill is adjusted during the process.  The holes can be made in the workpiece with more speed and also can performed at a decent speed.It is also easy to operate and easy to maintain the efficiency of the operator.  It can be use quickly because the versatile machine can easily counter holes,punches hole and grind out large particles.We also can handle large piece of material using this machine.

c.Explain the steps for drilling the the tap hole and ream hole. TAP HOLE

1. Prior to drilling the hole you will eventually tap, determine what size you need to drill for the bolt you are trying to screw in.

2. Your hole will be smaller than the diameter of the bolt, because the threads tapped will increase the diameter.

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3. Once you know what size hole you need to drill, go ahead and drill it in the designated location. Be conscious of how deep the hole is if it does not go all of the way through.

4. If you are using a hand tap, you may need to drill a deeper hole to account for the part of the tap at the end that doesn't create complete threads.

5. Now that you have a drilled hole, use the tap of the correct size and a tap handle to thread the hole.

6. To begin tapping, rotate the taper bit clockwise until you feel resistance from the threads cutting into the material.

7. From there, for every full rotation clockwise, make a half rotation counterclockwise.

8. This will break off any chips that have been created and clear the space for the cutting teeth of the tap to keep cutting.

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9. Taps are very brittle, so accumulation of these chips or any other extra stress on the tap could cause it to break in your material.

10. Make sure to pay attention to any abnormal resistance or binding you feel as tapping, and when in doubt, back the tap out a few threads and retry. You can also use lubricant of some sort to make tapping the hole easier.

11. Once you have used the taper tap to go either all the way through the hole, or as deep as a blind hole will allow, you can use a bottom tap (if available) to complete the threading closer to the bottom of the hole.

12. Choose your reamer. Hand reamers work best in soft materials such as wood or plastic. Begin by choosing the size reamer to which you need your hole bored out. A hand reamer will have a square shank and depending on the size of the reamer, you’ll fit the shank into either a tap wrench or crescent wrench to turn it

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REAM HOLE

1. Choose a tap and drill set in the size you need. Tap and drill sets include drill bits and taps that match each other so you can drill a hole with the bit, then use the tap that corresponds to it to add threads. Look for a set that includes both taps and drill bits at your local hardware or home improvement store

2. Clamp the metal in place with a vise or C-clamp so it doesn’t move. If the metal that you’re drilling moves, it could cause the drill bit to slip off, which could potentially cause an injury. Place the metal in a vise and tighten it so it’s secure, or attach a Cclamp on it to hold it in place.

3. Use a center punch to make a divot where you plan to drill. A center punch is a tool that’s used to knock a divot into a surface, allowing a drill to grip and penetrate the

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surface more effectively. Use an automatic center punch by placing the tip against the metal and pressing down until it knocks a divot. For a regular center punch, place the tip against the metal and use a hammer to tap the end and create a divot

4. Insert the drill bit into the end of your drill. Put the drill bit into the chuck, which is the end of your drill. Tighten the chuck around the bit so it’s held securely in place.

5. Apply drilling oil into the divot. Drilling oil, also known as cutting oil or cutting fluid, is a lubricant that helps prevent the drill bit from overheating and makes it easier to cut through the metal. Squeeze a drop of the oil directly into the divot.

6. Place the end of the drill bit into the divot and start drilling slowly. Take your drill and hold it over the divot so the bit is pointing straight down. Press the end of the bit into the divot, apply pressure, and start drilling slowly to begin penetrating the surface.

7. Bring the drill up to medium speed and apply consistent pressure. As the bit cuts into the metal, slowly increase the speed of the drill. Keep the drill at slow to medium speed and apply gentle but consistent pressure against it.

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8. Remove the drill every 1 inch (2.5 cm) to blow out flakes. Metal flakes and shavings will create more friction and cause your drill bit to heat up. It can also make the hole uneven and rough. As you’re drilling through the metal, remove the bit every now and then to blow out the metal flakes and shavings. Then, replace the drill and continue cutting until you pierce through the metal.

d. Explain all the safety measures taken during the process 1)

Before any work is carried out in the workshop, permission must be obtained from the workshop supervisor or lecturer. This is to provide protection and assistance in case personal injury should occur.

2) Remember to wear the safety glasses with side shields or goggles every time when carry on workshop practice. Wearing safety glasses is to protect you out of danger that may occur during workshop.

3) Use a brush to remove chips from drilling machine. Do not use your hands. Chips are not only razor sharp, they are often extremely hot.

4) Various cutting oils, coolant, and solvents may affect our skin. The result may be a rash or an infection. Avoid direct contact with these products as much as possible and wash our hands as soon as possible after contact.

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5) Hacksaws should be held by the handle, not the frame. Choose the correct blade for material being cut. Secure the blade with the teeth pointing forward if you want to cut on the push stroke; backward if you want to cut on the pull stroke. Keep saw blades clean and use light machine oil on the blade to keep it from overheating and breaking.

6) If any errors occurs while conducting the machine, shut it down and report the problem to the lecturer or supervisor.

7) Work areas and equipment are to be thoroughly cleaned after use. For example, clean up oil and grease or other liquid which spills on the floor otherwise they may causes accident.

10. Conclusion In conclusion, the project has provided us the knowledge regarding the turning process which is a form of machining and removing several parts of a material by cutting away unwanted parts in a rotational motion way. This process involved a machine called turning machine or lathe machine. During the workshop session, we have to use and handle

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the machine properly and safely. Many things we learnt while carrying out the turning process including the cutting parameters of the process. These parameters are listed as the cutting feed, cutting speed, spindle speed, feed rate, axial depth of cut and the radial depth of cut. These specification aspects are highly essential as it will determine the value of the end product of out workpiece. Furthermore, we have to use the right techniques to handle the components of the lathe machine and the correct way of using the tools in the tool box. The most important thing is the safety of the student while handling the machine. Besides, benchwork is importance because it can allow us very convenience operations in the engineering field with different tools and portable tools to be used on it. Benchwork offers greater work finish and a fairly good degree of accuracy. Moreover, the benefits of benchwork are allows employees to manage their workspace more affectively and it can bring extra strength to the project. There are many suggestions to improve the results of benchworks. First of all, we have to avoid from make an error during doing this experiment. We need to do the rotating speed correctly because it is highly advised to ensure the material thickness, tool and the speed compatibility to achieve accuracy. Secondly, we have to avoid from human error where human do make mist...