Producing Components Using Hand Fitting Techniques 3o442x

Sophie Paveling Handfitting Questions

Producing components using hand fitting techniques 1) Describe the health and safety requirements and safe working practices and procedures required for the hand fitting activities undertaken. When performing any hand fitting job there are many safety requirements that need to be undertaken to ensure that the all personnel are safe and are in no risk. Such things include wearing the correct P.P.E, and informing all surrounding people on the job that you are to perform e.g. using the drill. Alongside this a risk assessment is to be created on the area that is to be worked on, this will analyse all machinery, tools and space identifying all risks and health hazards.

2) Describe the importance of wearing appropriate protective clothing and equipment (PPE), and of keeping the work area safe and tidy Wearing the correct P.P.E is extremely important, this will protect the person from getting trapped or hurt in any way. Examples of this include: wearing overalls and sometimes safety glasses to protect the skin from getting infected by the swarf off the material. Another example would be wearing safety boots with steel toe cap to ensure that the feet are protected from any potential falling objects. Keeping the work area safe and tidy is also extremely important, this will eliminate any potential damage to all personnel in and around the area. The swarf can easily pierce the skin, therefore the sides must be wiped clean and all swarf is to be removed to eliminate the risk of someone leaning on it or touching it.

3) Describe the hazards associated with the hand fitting activates (such as use of power tools, trailing leads or hoses, damaged or badly maintained tools and equipment, using files with damaged or poor fitting handles), and how they can be minimised. The hazards associated with hand fitting activities include the use of: power tools- These can be extremely temperamental, they must be only used by a competent or trained personnel, if they get used by someone who has no knowledge on how to use it, it puts all others in risk of getting hurt. Trailing leads- these are a large trip hazards, if someone has no knowledge of the cabling being there they could potentially fall over and damage themselves. This incident will also happen when considering hoses around the work shop, they must be placed in a designated place safely away from everything. Damaged or badly maintained tools and equipment can cause damage to not only the person using it but other people surrounding. If a tool is broken e.g. a hammer head has become loose to the handle, it runs the risk of coming off the handle and potentially hitting other people. To minimise all these issues, checks must be -performed on the tool work before use.

Sophie Paveling Handfitting Questions

4) Describe the procedure for obtaining the required drawings, job instructions and other related specifications. All documentation for the job is located in the cabinets, if any job instructions are required they will be provided by a competent personnel or will be supplied with the job request.

5) Explain how to use and extract information from engineering drawings and related specifications (to include symbols and conventions to appropriate BS or ISO standards), in relation to work undertaken. On the documentation given for the task, there is a drawing of the finished object. On the drawing there is a 1st and 3rd view. The 1st view is the ‘Eye-Object View’ the 3rd view is the ‘Eye-View-Object’ view. The drawing also has specified measurements, these measurements are measured in imperial or metric. Imperial is: ‘Feet, Inches and Yards’, metric is: ‘Millimetres, Centimetres and Meters’. All these drawings are to be t the British standards, to ensure they are to spec there is a number written on the drawing e.g. ‘BS8888’ this states the drawing is written to the required specifications of the BS. Examples of the symbols in the drawing include: the circle with the line cutting through it, this symbol represents the diameter, the ‘R’ stands for the radius.

6) Explain how to interpret first and third angle drawings, imperial and metric systems of measurement, workpiece reference points and system of tolerance. The ‘Datum’ is the reference point where all measurements are to be taken from. This datum edge is to be filed down until it is flat and provides very accurate measurements. Tolerances are placed on all components to ensure that the required work piece is made correctly and is to the specifications of the job. The tolerances change all the time but can vary dependent how important the work piece is, tolerances can include 0.25mm. If this tolerance was to be put in practise with a 60mm length bar, the minimum it can be cut to is 59.75mm and the maximum would be 60.25mm. On the documentation given for the task, there is a drawing of the finished object. On the drawing there is a 1st and 3rd view. The 1st view is the ‘Eye-Object View’ the 3rd view is the ‘Eye-View-Object’ view. The drawing also has specified measurements, these measurements are measured in imperial or metric. Imperial is: ‘Feet, Inches and Yards’, metric is: ‘Millimetres, Centimetres and Meters’.

Sophie Paveling Handfitting Questions

7) Explain how to prepare the materials in readiness for the marking out activities, in order to enhance clarity accuracy and safety (such as visually checking for defects, cleaning the materials, removing burrs and sharp edges, applying a marking out medium).

When the material has been collected for the job, a few checks are to be made to ensure that the quality of the material matches the specifications. These checks include: measurementthe material should be measured to ensure that it is fit for purpose and the person performing the job can make the piece using that size material. Another check includes visually inspecting the material for any burrs or defects, this can include deep scratches or dents in the material; dents and scratches may affect the end product. If there are any burrs on the material they can easily be removed using a file. Once all checks are done and the material has no defects the material is to have a small layer of engineers blue applied to it, this dye will allow people to mark out the measurements on the material accurately.

8) Explain how to select and establish a suitable datum; the importance of ensuring the marking out is undertaken from the selected datum, and the possible effects of working from a different datum. The datum edge needs to be a flat edge of the material, this edge will need to be filed down and measured against a 90degrees square to ensure that the edge is completely flat and has no uneven edges or bumps. From this edge all measurements can then be taken, these measurements will be extremely accurate due to the flat surface. To ensure that, that certain edge only gets used a recommended marking should be placed on it displaying its function. If measurements were done off any surface edge then they will be inaccurate and run the risk of not reaching the specifications of the job aligned.

9) Describe the methods of holding and ing the workpiece during the marking out activities, and equipment that can be used (such as surface plates, vee blocks and clamps, parallel bars, screw jacks). When marking out the material a few accessories are available to use to ensure that the material is stabilised and secure; increasing the accuracy of the marking outs. These piece of equipment include: surface plates- surface plates are used when the material needs to be pushed against something to ensure there is a flat edge and the measurement will be straight. Another piece of equipment is the V-Block, this is used when the material needs to be stabilised also. The material is place within the V part of the block, this allows the person to use the gauge to gather where the bottom of the piece is and measure up however far needed.

Sophie Paveling Handfitting Questions

Clamps are also used, these will hold the material down to the marking out table. They provide stability to the piece and will ensure it won’t move when marking out is being performed.

10) Describe the use of marking out conventions when marking out the workpiece (including datum lines, cutting guidelines, square and rectangular profiles, circular and radial profiles, angles, holes which are linearly positioned, boxed and on pitch circles). Pitch circle diameters are a series of holes marked out around a given diameter the holes are equally spaced apart (angularly) and reference books such as a Zeus book can be used to establish the hole positions. Radial and circular profiles can be marked out using steel dividers and then cut and filed to establish the correct profile (the radius can be checked using a radius gauge). Holes on a linear axis can be marked from a datum edge to a singular point meaning that all holes come from the datum edge.

11) Describe the ways of laying out the marking out shapes or patterns to maximise use of materials. A way of maximising the use of material is to cut out accurate templates of the shapes needed to be cut, these templates can then be arranged on the material allowing visual measurements on what you can cut and where to ensure as much material is saved as possible. Another way to save material is to always start the shape from the edge, this way it won’t leave an awkward shape that can’t be used for anything else. 12) Describe the need for clear and dimensional accuracy in marking out to specification and drawing requirements. It is extremely important to ensure that all marking out is clear and the dimensions are very accurate. All material cut outs must be within the specified tolerances, if the marking out is not done accurately they run the risk of drawing the material out of spec therefore it won’t be accepted. 13) Explain how to set and adjust tools (such as squares, protractors and verniers). Vernier Caliper- The Vernier Caliper has main jaw that are used for measuring external diameter, as well as smaller jaws that are used for measuring the internal diameter of objects. To set up this tool, the first thing to do is to unlock the screw, this will loosen the caliper allowing you to extend and retract, then close the jaws (this is for calibration reasons), the reading should be ‘0’, if not, then the reading will not be accurate. Square – The engineers square is a simple measurement tool used to measure the datum edges and display if the edge is flat or not. This Engineers Square needs to be cleans before use to enhance the accuracy. Once cleaned the object is to be pushed against the vertical side of the

Sophie Paveling Handfitting Questions

engineers square then pushed up to the vertical side keeping the material square. It is recommended that the engineers square is to be pointed towards the light; any light that travels through shows a different surface level. A protractor is a simple measuring to set up and adjust. This measurement tool has a centre point, this centre point must be placed flush with the starting line of where you’d like to have the angle at. 14) Describe the importance of using tools only for the purpose intended; the care that is required when using the equipment and tools; the proper way of storing tools and equipment between operations. Every tool is made to perform a specific job, it is not made for multiple jobs e.g. a file is made to file down a material to a certain size or to smooth a surface. This tool must not be used for any other purpose; it can become very dangerous. If someone chooses to use a file as a hammer then there is the risk of the file head coming out of the handle socket. The file is not placed in to the handle as securely as a hammer. If the file is to come out of the handle it runs the risk of flying off and hurting the surrounding people or damaging machinery. When finished with the tool it should be checked over to ensure that there is no damage to it and it is safe for the next person to use. When finished with the tool and it is safe it should be stored in a safe place that is away from people and inaccessible to unauthorised personnel an example of this would be a cupboard with a lock on. 15) Describe the cutting and shaping methods to be used, and the sequence in which the operations are to be carried out. There are many cutting and shaping methods available when producing shapes on material, examples of this include: 

  

Saws – hacksaw provide a fine tooth approach to cutting material. This device is driven by hand and the direction of cut can be adjusted during the cut depending what shape has been requested. This method however can leave a rough edge and will need to be smoothed down with a file. Following the hacksaw there is the coping saw, this saw is used for far more intricate shapes, or thinner material. This saw can be used following the hacksaw to finalise the shape and add extra detail. Tin snips – these can be used to cut the material to the required shape, they will however leave sharp edges and quite a rough look, they will need to be followed by a file. The drill – this provides any form of shape required dependent on the drill piece selected. This will provide internal shapes.

Sophie Paveling Handfitting Questions

16) Describe the various types of file that are available, and the cut of files for different applications. Types of file include:     

Hand File – This is used for general filing of metals such as steel. They have a rectangular section and are most common in workshops. Half Round File – This file is used for filing curved surfaces. The shape of this file is a normal shaped round file with one side flat. This is perfect for creating curved edges. Three Square File – This file is triangular in section and is extremely useful when filing tight corners/angles. Knife File – This file is used when there is very little space. Square File – This file is used for making slots in material.

17) Describe the importance of ensuring that file handles are secure and free embedded foreign bodies or splits. The file handle hold vast responsibility when it comes to the operation of the tool. The file is slotted into the handle for stability. If the handle has any form of crack or chip in it, it can cause implications such as the handle can become lose to the file or the handle may cause injuries such as cuts or splints. Following this, before use of the tool the handle and file are to be checked. If the handle is lose from the file it must be sent off for repair and not used. 18) Explain how to prepare the components for the filing operations (cleaning, deburring, marking out) Before the component is to be filed various things need to be performed on the material first, these include:    

Cleaning the material – removal of excess material e.g. dirt, rust or mould. Remove the burrs – Remove all sharp surfaces or excess material using a file or a deburring tool. Dying the material – The material is to have engineers dye put on it to allow marking out to be clear. Marking out – Using a making out table, rule, scribe and other measuring tools required marked out the measurements for the component.

19) Describe the use of vice jaw plates to protect the workpiece from damage. Vice Jaw plates are inserted in to the vice and rest on the gripping plates. The jaws are used to protect and hold the material in place while it is being worked on. These jaw plates have a rubber surface, this surface protects the material from any dents/scratches that can be created from the force of the vice.

Sophie Paveling Handfitting Questions

20) Explain how to file flat, square and curved surfaces, and how to achieve a smooth surface finish (such as by draw filing, the se of abrasive cloth, lapping using abrasive pastes). To file flat the following is to be performed: The file is to be held by both hands and is to be held flat against the surface. This is then pushed forward and the cut is made on the forward stroke. The file then needs to be lifted and returned to the starting point. If the file hasn’t got a good surface finish draw filing will achieve this. Draw filing is: holding the file with both hands on each end of the blade, the blade is then pushed forward and back on the material. To file a square surface a square file or a flat file is to be used. These files will ensure that the flat surface will stay flat. The square 90 degree corner will come with the straight filing. This can be measured using an engineer’s square. To file a curved surface or produce a curved surface a round or half is to be used. These files will follow the already made curve or will indent the material enough to form the required curve. To smooth the curved surface down abrasive cloths can be used, these will remove the excess material on the surface and make it all level – making it smooth.

21) Explain how to select saw blades for different materials, and how to set the blades for different operations (such as cutting externally and internally). On a hacksaw there are many types of blades, these blades are different in many ways, one of the ways is through the amount of teeth it has:    

A 14TPI blade is used for cutting large sizes, aluminium and other soft metals. A 18TPI blade is used for general workshop cuttings A 24 TPI is used for cutting steel plate up to 5/6mm 32TPI is used for cutting the hollow sections and tubing.

When cutting externally the blade will be facing outwards towards the material and it will be cut that way. If an internal cut is to be processed, the blade itself can be taken out of the handle, placed through the hole facing the way it is to be cut and attached back on to the handle, the hacksaw can then be used to cut the inside of the hole to form the required shape. 22) Explain how to cut external threads using hand dies, and the method of fining and adjusting the dies to give the correct thread fit. When producing an external thread a hand die is to be used, this hand die has teeth, these teeth hold on to the material and when turned it produces the external thread. When the hand die is being turned, it must have a vast amount of lubrication applied to it, this is due to the heat of the material becoming hot and expanding it can also dry quickly and re stick to the material; this can break the hand die. When turning the hand die it must be brought back after every two turns, this is because of the built up of swarf. The routine is 2 turns forward, half a turn back. If this procedure is not performed then the hand die will become blocked and break.

Sophie Paveling Handfitting Questions

23) Explain how to determine the drill size for tapped holes, and the importance of using the taps in the correct sequence. When creating a tapping holes there is a chart that displays the drill and tapping size comparison. This table clearly displays what thickness is needed to be left for the tap to go through. If I was to produce a tap I would go to this table and see what size drill piece is needed. When tapping the hole or external thread, there are three steps within the sequence. Through the three steps the thread gets thicker, and cuts more into the material. These steps need to be followed, if not follows it runs the risk of snapping the tap or damaging the material. 24) Explain how to prepare drilling machines for operations(such as adjustment of table height and position; mounting and securing drills, reamers, countersink and counterbore tools in chucks or morse taper sockets; setting and adjusting spindle speeds; setting and adjusting guards/safety devices. When setting up the drill various things are to be processed before any operation is to be performed, these include:    

The first thing to do is to adjust the table height to the correct height. The correct height is discovered by the amount the drill can come down and if it can travel enough distance. The position of the table is determined by what part of the material needs cutting or if the material is too big for the minimum table height adjustment. The material is then to be mounted and secure down with the clamps. Depending on the material and size of the drill the speed and feed will be adjusted to fit. There is a chart displaying these figures next to the drill.

25) Explain how to mount the workpiece (such as in a machine vice, clamped to table, clamped to angle brackets); techniques of positioning drills to marking out, use of centre drills and taking trial cuts and checking accuracy, and how to correct holes which are off centre. A machine vice is used on a drill or milling machine. When used on the drill its main duty is to position the material in the correct place and secure it while it is being worked on. To mount the workpiece on the machine vice the machinist is to place it in and secure it in a certain way and secure it themselves. Once it is in the machine vice, this vice is to be clamped to the table. There are small screw clamps on the drill that grip the vice and hold it down to the table. These are to be tightened up until the vice can’t be moved. When setting up the drill piece, the drill is to be placed in the clutch and tightened up. Once tightened up the drill should manually be pushed down and up and positioned accordingly to the centre drilled hole or hole punch.

Sophie Paveling Handfitting Questions

A trial cut can be taken if accuracy is key, this form of cut only takes a small later of the material off and gives an indication on where the drill piece is in comparison to the marked hole. If a hole is off centre when punching it with a punch and hammer a simple slant on the punch will moved the dented hole to the correct position, then in the new position a straight punch is to be done.

26) Explain how to produce a sliding or mating fit using filing, scraping and lapping techniques. Fits of this kind are intended for the accurate location Parts made to this fit turn and move easily. To produce a sliding fit the following techniques can be used:

 Filing – There are a large variety of different shaped files each with a different job

 

and ability. There are flat files used to file flat surfaces and curved to create a curved surface. Dependent on the sliding fit these files will be used to create it. The two pieces of material will need to continuously be checked with each other when filing is being performed. Scraping – This method is essentially like using a scraper. It is a blade with an edge folded over and will give a smooth finish and remove excess material with ease. Lapping - Lapping is used to create a very fine surface finishing. The purpose of this technique is to remove any unwanted scrapes or marks that are very minor. This is the final technique used to create the perfect fit.

27) Describe the problems that can occur with the hand fitting activities, and how these can be overcome (such as defects caused by incorrectly ground drills, inappropriate speeds, and damage by work holding devices). If the component is to be drilled and the drill piece used is blunt or has seized, it runs the risk of damaging the material itself or not cutting into it at all. This can be corrected by sharping the drill on a grinder or if not trained retrieving another drill piece that is sharp. If the drill piece has already damage the material then the correction to be made is to (if not drilled in too far) repeat the process on the other side of the material, drill the hole through the other side, or if possible drill a bigger hole and adjust the other side of what the component is connected to. If the drill is on the wrong speed then it will run the risk of getting stuck in the material or braking the drill piece. If the drill is stuck in the material, it can be drilled out with another drill bigger than that one. If the drill bit has just snapped and come off the drill piece is to be replaced and the speed will need to be adjusted. The work holding devices can cause indents on the material, these indents can affect the operation of the material or make it look rough. If there are slight indents on the material then

Sophie Paveling Handfitting Questions

these can be removed using a file. To avoid the potential damage there are covers available to place over the jaws of the vice or blocks of wood can be placed around the component.

28) Explain when to act on their own initiative and when to seek help and advice from others A person shall only act on their own initiative when they are qualified and competent enough to perform the job without assistance. If they feel that they are not trained enough or they begin to question the job they are performing they should question a trained personnel for advice or guidance. 29) Describe the importance of leaving the work area in a safe and clean condition on completion of the fitting activities (such as removing and storing power leads, isolating machines, removing and returning drills, cleaning the equipment and removing and disposing of waste). It is extremely important for the work area to be left in a safe and clean condition. All excess debris must be removed and all tools should be put back into the allocated location. If this task is not performed it runs the risk of someone coming over and getting swarf in their skin or clothing, also it runs the risk of an unauthorised and untrained personnel using the equipment.