Teknologi Dan Rekayasa POWER DRIVENS HAND TOOLS

USE THE POWER DRIVENS HAND TOOLS Objectives : After studying this unit, the student will be able to : Select the power driven hand tools. List the uses for power driven hand tools. List the precautions to be followed to insure the safe operation of power driven hand tools. List the safety rules for the use of power driven hand tools. Teknologi dan Rekayasa

POWER DRIVENS HAND TOOLS All power driven hand tools are energized by an electric current. The electric current drives an electric motor which is the heart of the tool. The motor converts the electrical energy to mechanical energy wihch does the work for which the tool is intended. The worker must always follow certain precautions in the use of power driven tools to prevent the possibility of a shock. An electric shock is the passage of an electric current through an individual’s body to the ground to complete an electrical circuit. Teknologi dan Rekayasa 3

POWER DRIVENS HAND TOOLS It necessary to check that : The tool is grounded properly with a third wire The cord and tool are properly insulated The operator is not in contact with wet or damp ground The operator is not in contact with an outside source of current. The cord is not crimped. Teknologi dan Rekayasa 4

POWER DRIVENS HAND TOOLS For proper operation, electric tools a constant line voltage as specified on the nameplate of the tool. A low line voltage will cause a decrease in the speed of the tool and a high voltage will increase the speed. In both cases, the tool will heat up quickly. Excessive heat will damage the tool. The value of the line voltage supply should be compared with the rating on the nameplate of the tool to insure that they are compatible. Teknologi dan Rekayasa 5

POWER DRIVENS HAND TOOLS As the distance between the point of use of the tool and the source of power increases, extension cables must be used. The conductor wires of the extension must be of the correct size so that a constant line voltage is maintained. Teknologi dan Rekayasa 6

ELECTRIC DRILL One of the most useful power driven tool is the electric drill. Both standard general purpose and heavy duty drills are available. Both types of drills can be obtained with chucks sized to hold ¼, 3/8 or ½ inch drills. Single speed and available speed electric drills are available. Trigger speed controls are mounted in the drill handle. There are three types of drill handles: in-line grip, pistol grip, and side grip. Teknologi dan Rekayasa

ELECTRIC DRILL For variable speed drills, the speed can be controlled from zero rpm to the maximum rpm rating of drill. Some drills have reversible motors controlled by a switcth located bellow the trigger switch. All drills have heat treated, helical alloy steel gears and hardened shaft, key type chucks. The following accessories added to any type of drill: right angle drive unit, grinding wheel, wire wheel brush, cloth buffing wheel, or extension shanks. Teknologi dan Rekayasa 8

ELECTRIC DRILL

HOW TO USE AN ELECTRIC DRILL Variable Speed Drill Mark the center of the hole to be drilled. Tighten the drill bit in the chuck with a key. Place the drill point on the center of the hole to be drilled. Hold the drill bit at a 90 degree angle to the surface to be drilled with the drill point on the center punch mark. Press the trigger switch of the drill on and off until the hole center is secured. Teknologi dan Rekayasa

HOW TO USE AN ELECTRIC DRILL Singe Speed Drill Mark the center of the hole to be drilled and center punch the location. Tighten the drill bit in the chuck with a key. Hold the drill bit at a 90-degree angle to the surface to be drilled with the drill point on the center punch mark. Press the trigger switch of the drill on and off until the hole center is secured. Teknologi dan Rekayasa 11

HOW TO USE AN ELECTRIC DRILL Teknologi dan Rekayasa 12

HOW TO USE AN ELECTRIC DRILL Press and bold the trigger switch on and apply forward pressure to the drill until the hole is drilled. CAUTION : Never try to hold a turning chuck. Remove the chuck key before starting the drill. Turn the drill off immediately if the bit start to bind in the material. Avoid excessive pressure. Teknologi dan Rekayasa 13

PORTABLE GRINDER The portable grinder is available with 4-, 5-, or 6-inch grinder wheels. It is driven by a 115 volt, 60 HZ, 4000 – 6000 rpm motor. It is factory lubricated for an initial operating period of 2 to 6 months, depending upon the amount of use. The portable grinder has a lightweight aluminum alloy housing, an adjustable shatterproof steel guard, an enclosed dustproof switch, helical alloy steel gears and shaft, and oversize ball bearings. Teknologi dan Rekayasa 14

PORTABLE GRINDER Commonly used accessories are the crimped wire brush and the cloth buffing wheel. Teknologi dan Rekayasa 15

HOW TO MOUNT GRINDING WHEELS Disconnect the tool from the electric outlet. Remove the wheel guard cover by removing the screw at the top of the cover. Hold the wheel and remove the spindle nut with a wrench. Lift off the outer wheel flange, rubber flange washer, and the grinding wheel. Teknologi dan Rekayasa 16

HOW TO MOUNT GRINDING WHEELS Clean the spindle and threads. Replace the grinding wheel, rubber flange washer, and the grinding wheel. Replace and tighten the spindle nut. Replace the guard cover and fasten it securely. Run the grinder at full speed for about a minute. Teknologi dan Rekayasa 17

HOW TO USE THE PORTABLE GRINDER Grasp the grinder firmly, allow the motor to reach full speed. Apply the wheel to the work gradually. The grinder may be used with the wheel held parallel to the work or the wheel may be placed at an angle to the work. CAUTION : Never use the side of the wheel for grinding. If the grinder begins to bind on the material, remove it immediately. Never use a damaged or badly worn wheel. Teknologi dan Rekayasa 18

SAFETY Each worker must assume responsibility for the safe operation of any equipment he is using. The worker must maintain and operate any machine in strict conformance with the manufacturer’s safety rules and guidelines and those established by the Occupational Safety and Health Act. Accident in the shop are caused by careless, preoccupied and overconfident people.

SAFETY RULES FOR POWER DRIVENS HAND TOOLS The following safety rules for the use of power drivens hand tools. Know your power tool Ground all tools unless double insulated Keep guards in place and working order. Keep the work area clean Avoid dangerous environments Keep all visitors away from the work area Store unneeded tools

SAFETY RULES FOR POWER DRIVENS HAND TOOLS Don’t force any tool Use the right tool Wear the proper apparel Use safety glasses with most tools Don’t abuse the electrical cord. Secure your work Don’t overreach. Maintain tools with care. Disconnect tools. Remove adjusting keys and wrenches. Avoid accidental starts

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