Cairo UniversityFaculty of Engineering Fundamental of manufacturing Report on c-clamp Supervised by: Prof. ----------------------- May 2012
Submitted by:Ahmed raafat 111111Amr Hany AHMED 1101056Kareem Hossam Ahmed 111111Mohamed Mahmoud saber 111111Wassim raafat shanad 111111------------------------------------ 111111------------------------------ 1111111--------------------------------- 1111111---------------------------------- 1111111---------------------------------- 1111111--------------------------------- 1111111------------------------------------- 1111111
Introduction: A C-clamp is a type of clamp device typicallyused to hold a wood or metal work piece, and isoften used in, but is not limited to, carpentry andwelding. These clamps are called "C" clampsbecause of their C shaped frame, but are otherwiseoften called G-clamps or G-cramps becauseincluding the screw part they are shaped like anuppercase letter G.
Objective of the project: The main objective of the project is to learnthe techniques of the various types of machinesused in lab and learn how to operate them insequence of processes in order to fabricate a wellfinished product that is functional and useable.
Usage A C-clamp is used by turning the screw throughthe bottom of the frame until the desired state isreached. In the case that the clamp is being tightened,this is when the objects being secured aresatisfactorily secured between the flat end of thescrew and the flat end of the frame. If the clamp isbeing loosened, this is when a sufficient amount offorce has relieved to allow the secured objects to bemoved.
Work plan: We start the project by applying the “ProcessPlanning” as follow: Deciding what process and methods should beused and in what sequence. Determining tooling requirement. Selecting production equipments and systems.
Sequence of processes used in part fabricationStating raw Finished material product Basic Secondary Property-enhancing Finishing process processes processes operationsBasic process: Establishes the initial geometry of the part.Secondary process: Transform the basic shape into the final geometry.Finishing operations: Provide a coating on the work part surface.
Lab work We were provided with a C section with a greatlength, the first task was to cut it to the length neededto produce the work part “C-clamp”. Drawings and dimensions of the work piece before and after cutting it.
The second task was to drill a hole of 10mmdiameter for he bolt and nut to make the holdingpart of the C-clamp. the following image shows atop view of the work piece after drilling
The last task was welding the nut right above thedrilled hole and putting the bolt in it. Image of the work piece after welding the nut.
Dimensions We used the standard dimensions of sectionexcept for the length. After measuring all otherdimensions on the C-clamp as sketched above anddiscussing the results with the team, we conclude thatthe best length to cut was 38 mm. Part Dimension Length 38 mm Height 81 mm Web width 5.7 mm Flanshing thickness 6.7 mm Flanshing width 44.65 mm
Sequence of the processesForging: We started forging to make the surface ofthe C-clamp clean, we were instructed how to use theRasp;( hand files are normally held in both hands),the file is held flat against the surface to cut / smooth.The file is pushed forward and it cuts on the forwardstroke, then is lifted away from the metal andreturned to the starting point for the next pushforward. This is called „Through Filing‟
In the beginning it was difficult to use the Rasp as ourhands tend to shake which made the surface not flat.During that process we rotate the C-clamp to get thewidest cross sectional area, but we were told that itwas wrong, as the thinner cross-sectional area is thebetter ending for the product as this cross-sectionalarea will be forged by more teeth so it will be betterand faster.
Measurements: as mentioned above we located the center at thetop surface to drill a hole for the bolt and the nut.The next step was to get the bolt and nut (ISO 10),and then we were ready for welding. The final stepwas to paint the product to provide a smooth surface.
Rasp We use the word "rasp" to denote the entirefamily of the tool when were talking generally aboutthe use of the tool. When the particular details matter,we say "Rasps" to mean a rasp with a handle at oneend.There are many different shapes / sections of files,some are shown below. They are used for a variety oftypes of work. Files are classified according to theirlength, section / shape and cut (tooth shape).
Hand File: Used for general filing of metals such assteel. They are rectangular in section and are the mostcommon type of file used in workshops.Half Round File: Used for filing curved surfaces. Anormal hand file with its flat cutting edges is unsuitablefor filing curved surfaces. However, the half round filehas a curved surface which is especially useful for filinginternal curves.
Three Square File: Is triangular in section and veryuseful when filing „tight‟ corners / angles. The sharpedges allow the file to fit into corners when filing.Square File: The square file is quite thin and fits intocorners well. They can e used to file slots in metal orfor filing where there is little space.
Knife File: Knife files are very useful when filingwhere there is little space. Knife files are very thinand can fit into small gaps.
Shaping Plywood Regular files do not work well on wood, thetraditional tool for shaping wood is a rasp, which hasprojecting teeth to gouge out and remove wood. Thiscan be a bit rough on plywood.A rasp is a tool used for shaping wood or othermaterial. It consists of a point or the tip, then a longsteel bar or the belly, then the heel or bottom, then thetang. The tang is joined to a handle, usually made ofplastic or wood.
Welding Process for joining separate pieces of metal ina continuous metallic bond. Cold-pressure welding isaccomplished by the application of high pressure atroom temperature; forge welding (forging) is doneby means of hammering, with the addition of heat.
Arc welding Arc welding is a type of welding that uses a weldingpower supply to create an electric arc between anelectrode and the base material to melt the metals atthe welding point. They can use either direct (DC) oralternating (AC) current, and consumable or non-consumable electrodes.
Resistance welding Resistance welding involves the generations of heatby passing current through the resistance caused bythe contact between two or more metal surfaces. Ingeneral, resistance welding methods are efficient andcause little pollution, but their applications aresomewhat limited and the equipment cost can be high.
Water-Gas welding Process was applied in the end of 19th century. Theflame which is produced from water-gas replaced theblacksmith s hearth as a mean of heating the metal andwelded the metal but this is first welding.
Cast-welding In this method the molten metal pouring into amould which has runner at the point where thecasting had failed to flow or wherever there was afractured place. The molten iron poured in until it wasfluid everywhere around the edge of the job andrunner was stopped up, and then the iron was allowedto cold in the mould.
Cast-welding This welding process can be said modernfusion weld process, but this is slightly high costprocess than other types of welding.
Submerged Arc Welding This process involves thewelding arc being continuouslysubmerged under a mound ofgranular flux. The bare metal isfed automatically at a rate whichmaintains the welding arc. As the arch and the molten metal are covered withthe mound of flux , there is no flash spatter, sparks orsmoke. The resulting weld is uniform with goodphysical and chemical properties.
Solid State Welding Solid state welding is a term used for weldingprocesses which produces joining at temperaturesessentially below the melting point of the basematerials, without the need for brazing filler metal.Pressure is generally required but not always. Thesewelding processes include cold pressure welding,diffusion welding, explosion welding, forge welding,friction welding, hot pressure welding, roll welding, andultrasonic welding.
Electron Beam Welding In this process a concentrated beam of electronsbombards the base metal, causing it to melt and fuse.The process is most efficient when done in a vacuum.Therefore the size of the vacuum chamber limits thesize of the work pieces that can be welded. Advantagesinclude the ability to produce welds of extremely highpurity, ability to melt any known material, ability toweld dissimilar metals and the ability to make weldswith depths as great as 150mm.
Electron beam welding is costly for two reasons, 1) the high cost of equipment, 2) the time lost in pumping out the vacuum chamberbetween welds. When the welds are not made in avacuum, many advantages of the process are reduced.
Laser Welding. The laser beam is a concentrated beam of lightwith sufficient energy to generate the heat at the basemetal surface to cause fusion. There are two types oflasers in use (1) gas lasers and 2) solid lasers. Gas lasersprovide a continuous laser beam that is best suited tocontinuous welding and cutting. Solid lasers releasetheir energy in short bursts or pusses at a rate of 6 to 10per minute.
As each pulse only lasts for a few millionths of asecond the base metal is liquid for only moments andthere is limited time for chemical reactions tooccur. Therefore flux type protection is not requiredto obtain sound welds.Laser systems can be precisely controlled and havesufficient power to weld and even vaporize any knownmaterial.
Other advantages include the ability to make weldsthrough transparent coverings and to make welds inlocations impossible to reach with conventional weldinggear. Limited depth of penetration however restrictsthe use of laser welding to relatively thin materials.