KJKL 1033 ASAS MEKANIK & ELEKTRIK

KJKL 1033ASAS MEKANIK & ELEKTRIK Lecture #6 – Fitting 15 May 2008 2.00 pm – 5.00 pm

FITTING • Tools for Fitting Work • Vernier Height Gauge • Tri-Square • Vice • Hack Saw • File Week 1

VERNIER HEIGHT GAUGE • The accuracy in completing a project (on workpiece) starts from marking works. • If the marking works are done appropriately and carefully, it will lead to accurate measurement or dimensioning and thus, producing high quality finished work. Week 1

VERNIER HEIGHT GAUGE • In order to implement accurate marking work, a person must: • Read and understand drawings • Choose and use the right tools • Able to translate or transfer accurate measurement from drawing to work specimen or workpiece • After completing the marking exercise, recheck all the dimensions with the drawings to ensure they are accurate Week 1

VERNIER HEIGHT GAUGE • For obtaining measurement accurate to 0.02mm the vernier height gauge is commonly used. • A vernier height gauge is commonly used to measure and mark distances with 0.02mm accuracy Week 1

VERNIER HEIGHT GAUGE • Maintenance – Vernier height gauge requires proper maintenace and care. The accuracy of this tool depends on its maintenance and careful usage. Some of the proper maintenance and handling steps that should be taken: • Store after use • Do not drop or knock it • Store in room with controlled temperature • Do not heat • Clean tool before and after use • Do not take measurement on rotating specimen • Do not keep with other working tools Week 1

VERNIER HEIGHT GAUGE • Parts – Some of the primary parts on the vernier height gauge are: • Base • Beam • Vernier Scale • Scriber • Scriber is attached to the vernier scale when doing markings (sketching). In addition, the scriber could also be detached and replaced by a dial indicator for inspection purposes. Week 1

VERNIER HEIGHT GAUGE • Figure BEAM CLAMP SCREW VERNIER SLIDE SCRIBER Week 1

TRI-SQUARE • Marking for 90o angles and measuring Week 1

VICE • Figure JAW FIXED SECTION MOVABLE SECTION SPINDLE HANDLE Week 1

VICE Week 1

VICE • The height of a vice is best positioned approximately leveled with our belly navel • The workpiece must be clamped firmly in the center of the vice – not too high above the jaws nor too outwardly exposed to the sides of the jaw. • Clamping too high or too outwardly from the vice jaws would lead to vibrations or shakings when working on the workpiece • Be sure the workpiece cross-section is flat and upright Week 1

VICE • For normal work, the vice need to be installed firmly on a work bench and leveled with the worker’s elbow i.e. approximately 44 in. from the floor (see figure), for working convenience. Week 1

VICE ENSURE ENOUGH CLEARANCE AT THIS SECTION WHEN INSTALLING VICE, ENSURE ITS HEIGHT IS LEVEL WITH THE ELBOW Week 1

HACK SAW • Hack Saw is used to saw / cut metals to necessary sizes and to saw-off thin / minor metallic portions that are extra / unnecessary from the marked work piece (scrap). • The advantage of cutting with this method is less waste / scrap is produced and the sawed surface could be easily finished. Week 1

HACK SAW • Parts – Parts of a hack saw (see figure): • i. Frame • ii. Handle • iii. Leveling / tensioning nut • iv. Blade BLADE LENGTH Week 1

HACK SAW • Frame • There are two types – fixed frame and adjustable frame • Fixed frame could only hold a fixed/constant blade length • Adjustable frame could be used to hold different blade lengths since it could be adjusted accordingly. Week 1

HACK SAW • Approach • Clamp / grip the metal to be cut appropriately (see figure). If sawing a thin metal, consider attaching thin soft metal piece or wood to sandwich the workpiece to be cut, using the vice jaw. Week 1

HACK SAW VARIOUS METHOD OF GRIPPING METAL TO BE SAWED Week 1

HACK SAW • Approach • Initially, saw slowly. Use thumb as guide and start sawing. When the cut mark is visible, stroke or saw consistently with good length. Normal sawing rate using a normal saw is approximately 40 strokes per minute. • When cut is almost complete, support or hold the hanging portion with other hand Week 1

FILE • Filing is a method to remove or shave minor or minute materials off the metal or solid work piece, either for: • Separation / removal • Smoothing • Cleaning / Finishing • File is a hand tool made of hardened and tempered steel where its face consists of cutting tooth lines crisscrossing from the sides. Week 1

FILE • Parts (see figure) NOMINAL LENGTH OF BLADE / BODY POINT OR TIP OF BLADE Week 1

FILE • Method • Right hand push and press • Left hand press ONLY • When filing, lean body forward (during forward stroke) at least a distance 2/3 from the base of your left thigh and return to original position at the end of the return stroke • Do regular, swift movement at medium speed. • The speed of the movement depends on the hardness of the filed workpiece. Slower motion on hard materials. Week 1

FILE • Method (cont..) • Use the whole length of the file • If filing flat surface, diagonalise your file 45o to the left and right to guarantee quicker cutting and removing of material (i.e. cross filling) Week 1

FILE Week 1

FILE • Holding and filing – There are many ways to hold a file and this depends on how much material is desired to be removed and the sort of finishing required : • Pressure filing – filing by applying high pressure for removing thick material rapidly Week 1

FILE • This approach is suitable to remove small amount of metal usually after rough filing • Doe not require high pressure from both hands Week 1

FILE • Similar as before – need not press too hard on both hands • Suitable to flatten surface of workpiece Week 1

FILE • Diagonal filing – another type of filing LINK: FILING www.eng.ukm.my/rasidi Week 1

KJKL 1033 ASAS MEKANIK & ELEKTRIK