5Power Tools.pdf

Tool Safety Power Tool Work Practices Tradespeople who use hand and power tools and who are exposed to the hazards of falling, flying, abrasive and splashing objects or are exposed to harmful dusts, fumes, mists, vapours or gases must be provided with the particular personal equipment necessary to p...

Tool Safety Power Tool Work Practices Tradespeople who use hand and power tools and who are exposed to the hazards of falling, flying, abrasive and splashing objects or are exposed to harmful dusts, fumes, mists, vapours or gases must be provided with the particular personal equipment necessary to protect them from the hazard. Tradespeople and employers have a responsibility to work together to establish safe working procedures. If a hazardous situation is encountered, it should be brought to the attention of the proper individual immediately. Appropriate Personal Protective Equipment (PPE) should be worn due to hazards that may be encountered while using portable power tools and hand tools. Floors should be kept as clean and dry as possible to prevent accidental slips with or around dangerous hand tools. PxHere, CC0 Public Domain Power tool in use 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 181 of 498 Hand Tool Misuse The greatest hazards posed by hand tools result from misuse and improper maintenance. Some examples: Using a screwdriver as a chisel may cause the tip of the screwdriver to break and fly, hitting the user or other employees. If a wooden handle on a tool such as a hammer or an axe is loose, splintered or cracked, the head of the tool may fly off and strike the user or another worker. A wrench must not be used if its jaws are sprung because it might slip. Impact tools such as chisels, wedges or drift pins are unsafe if they have mushroomed heads. The heads might shatter on impact, sending sharp fragments flying. Tradespeople are responsible for properly using and maintaining tools. Sparks Produced by Hand Tools Around flammable substances, sparks produced by iron and steel hand tools can be a dangerous ignition source. Where this hazard exists, spark-resistant tools made from brass, plastic, aluminium or wood are safer. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 182 of 498 Spark-Resistant Tools Non-sparking, spark-resistant or spark-proof are terms describing tools made of metals such as brass, bronze, Monel, copper-aluminium alloys, copper-beryllium alloys and titanium. Preferred non-sparking metals have less tensile strength than steels usually used to make tools. A lower tensile strength means the metal has less strength or resistance to tearing apart when stretched under test conditions. It also means these tools are softer, wear down faster than ordinary steel tools and have to be dressed more frequently. Spark-resistant tools 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 183 of 498 Power Tool Safety Safe Work Practices Power tools offer enhanced tool performance and greatly improve the speed in which tasks can be carried out. However, with enhanced tool performance comes the responsibility to address powertool safety issues and increased risk when operating power tools. Maintenance management professionals and technicians responsible for using power tools are also responsible for understanding a tool's safety features and ensure that the manufacturer's safety precautions and common sense are followed at all times. All hazards involved in the use of power tools can be prevented by following five basic safety work practices: Keep all tools in good condition with regular maintenance. Use the right tool for the job. Examine each tool for damage before use. Operate according to the manufacturer's instructions. Provide and use the proper protective equipment. Aviation Australia Safe work practices 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 184 of 498 Safety Guidelines The following are general safety guidelines for power tools. Individual manufacturers' tool owner/operator manuals, shipped with tools and accessories, are recommended as a final source for proper procedures for specific tool use. Know the power tool. Operators must read and understand the owner's manual. Labels affixed or included in the shipping container must be read and understood. Ground all tools unless they are double insulated. Avoid dangerous environments. Do not use power tools in a damp, wet and/or explosive atmosphere, such as in the presence of fumes, dust or flammable materials. Be aware of all power lines and electrical circuits, water pipes, and other mechanical hazards in your work area. In particular, be aware of those below the work surface that are hidden from the operator's view but may be contacted. Wear proper apparel. Do not wear loose clothing, dangling objects or jewellery. Long hair must be restrained. Gloves should not be worn when operating certain power tools. Check appropriate tool manuals. Power tools can be hazardous when improperly used. Understand the potential hazards as well as the safety precautions to prevent those hazards from occurring. Power Tools in Aviation All aviation workshops use a variety of power tools and machine tools. Fixed equipment is usually electrically powered, and portable power tools can be either electrically or pneumatically powered. Power tools and their supply of power, which may be electrical, pneumatic or mechanical, should be treated with care, respect and responsibility, as the tool and the power have the potential to cause damage and injury. In addition, tools are expensive and should be properly maintained to ensure serviceability and safety. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 185 of 498 General Safety Precautions The following general precautions should be observed by power tool users: Never carry a tool by the cord or hose. Never yank the cord or the hose to disconnect it from the receptacle. Keep cords and hoses away from heat, oil and sharp edges. Disconnect tools when not in use, before servicing and when changing accessories such as blades, bits and cutters. All observers should be kept at a safe distance away from the work area. Secure work with clamps or a vice, freeing both hands to operate the tool. Avoid accidental starting. Workers should not hold a finger on the switch button while carrying a plugged-in tool. Tools should be maintained with care. They should be kept sharp and clean for the best performance. Follow instructions in the user's manual for lubricating and changing accessories. Be sure to keep good footing and maintain good balance. The proper apparel should be worn. Loose clothing, ties or jewellery can become caught in moving parts. All portable electric tools that are damaged must be removed from use and tagged ‘Do Not Use’. When using electric tools, you must be aware of several dangers; the most serious is the possibility of electrocution. Among the chief hazards of electric-powered tools are burns and slight shocks, which can lead to injuries or even heart failure. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 186 of 498 Electric Power Tools Safety Precautions Under certain conditions, even a small amount of current can result in fibrillation of the heart and eventual death. A shock also can cause the user to fall off a ladder or other elevated work surface. Electric tools must have a three-wire cord with ground or be grounded, be double insulated, or be powered by a low-voltage isolation transformer. Double insulation is more convenient. The user and the tools are protected in two ways: by normal insulation on the wires inside, and by a housing that cannot conduct electricity to the operator in the event of a malfunction. General practices to follow when using electric tools: Electric tools should be operated within their design limitations. Gloves, if kept clear of rotating parts, and safety footwear are recommended during use of electric tools. When not in use, tools should be stored in a dry place. Electric tools should not be used in damp or wet locations. Work areas should be well lighted. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 187 of 498 Power Tool Accessory Precautions A variety of accessories are available for use on or with power tools. Caution must be exercised when selecting and using any accessory with any power tool. Choosing the wrong accessory or using an accessory incorrectly can result in serious injury. Do not use an accessory or attachment unless: The power tool manufacturer recommends its use on the product. The accessory limitations and specifications – such as speed, size, mounting and guarding requirements, etc. – match the limitations and specifications of the power tool as shown in the owner/operator's manual. Use of the accessory does not require the removal of or defeating of any guards, barriers or other safety-related devices on the power tool, unless they are replaced by other appropriate guards or protective devices. Unplug tools before installing, adjusting and changing any accessory or attachment of any kind. Power tool accessories 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 188 of 498 Powered Abrasive Wheel Tools Powered abrasive grinding, cutting, polishing and wire buffing wheels create special safety problems because they may throw off flying fragments. Before an abrasive wheel is mounted, it should be inspected closely and sound- or ring-tested to be sure it is free from cracks or defects. To test, wheels should be tapped gently with a light non-metallic instrument. If they sound cracked or dead, they could fly apart in operation and must not be used. A sound and undamaged wheel gives a clear metallic tone or ‘ring’. To prevent the wheel from cracking, the user should be sure it fits freely on the spindle. The spindle nut must be tightened enough to hold the wheel in place without distorting the flange. Follow the manufacturer's recommendations. Care must be taken to ensure that the spindle wheel will not exceed the abrasive wheel specifications. Due to the possibility of a wheel disintegrating (exploding) during start-up, never stand directly in front of the wheel as it accelerates to full operating speed. Portable grinding tools need to be equipped with safety guards to protect workers not only from the moving wheel surface, but also from flying fragments in case of breakage. In addition, when using a powered grinder: Always use eye protection. Turn off the power when not in use. Never clamp a hand-held grinder in a vice. Powered abrasive wheels - bench grinder 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 189 of 498 Portable Drills Available in a variety of types and capacities, portable power drills are undoubtedly the most-used power tools. If the drill is corded, check carefully for loose power cord connections and frays or damage to the cord. Replace damaged tool and extension cords immediately. Be sure the chuck is tightly secured to the spindle. This is especially important on reversible type drills. Tighten the bit securely as prescribed by the owner/operator's manual. The chuck key must be removed from the chuck before starting the drill. A flying key can be an injury-inflicting missile. Check auxiliary handles if they are part of the tool. Be sure they are securely installed. Always use the auxiliary drill handle when provided. It gives you more control of the drill, especially if stalled conditions occur. Grasp the drill firmly by insulated surfaces. Always hold or brace the tool securely. Brace against stationary objects for maximum control. If drilling in a clockwise or forward direction, brace the drill to prevent an anti-clockwise reaction. Do not force a drill. Apply enough pressure to keep the drill bit cutting smoothly. If the drill slows down, relieve the pressure. Forcing the drill can cause the motor to overheat, damage the bit and reduce operator control. Aviation Australia Portable drill 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 190 of 498 Bench Grinders The Bench Grinder A bench grinder is normally mounted to a bench and is fitted with a grinding wheel on each end of the shaft. Owing to the danger of the abrasive wheel shattering when running at high speed, the wheels are usually almost completely enclosed by a metal guard. Sufficient opening is left to place the work piece against the wheel. The abrasive wheels must not be operated without these guards securely in place. The illustration below shows various common grinders (including the bench grinder). New resource Grinders Bench grinders are used for off-hand (or hand-guided) grinding of small jobs and tools. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 191 of 498 Bench grinder Abrasive or Grinding Wheels Grinding wheels and the machines that drive them are used in engineering workshops. You do not need to know the exact type of grinding wheel for every piece of work. This information is readily obtainable in handbooks available from the makers and their agents. However, you should have a broad understanding of the construction and characteristics of grinding wheels in order to best use the limited range of wheels available at the workplace. It is essential to know, for example, whether a wheel is suitable for the material you want to grind. Such knowledge is also very useful for diagnosing and correcting common grinding faults, such as poor finish, burning, loading, glazing and excessive wheel wear. Types of Abrasive or Grinding Wheels Abrasive or grinding wheels are made from manufactured abrasive grains held together by a suitable material called the bond. Satisfactory results can be obtained only by using the right type of abrasive wheel rotating at the correct speed for the kind of work being performed. Two abrasives are used to make abrasive wheels: Aluminium oxide Silicon carbide. Aluminium oxide, called Alundum, is a hard, tough abrasive suitable for grinding high-tensile, tough materials and all types of steels. Silicon carbide, called Crystolon, is a harder abrasive than Alundum. It is used to grind hard materials such as stone or ceramics, non-ferrous metals and other non-ferrous materials. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 192 of 498 Grinding Wheel Inspection When a suitable wheel has been selected for the operation, carefully check it for visible flaws as shown in the diagram. These may include: Broken and chipped edges Cracks Damaged mounting bushes Damaged compressible washers. The wheel should also be dry and free from any loose material. Checking for wheel faults 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 193 of 498 Grinding Wheel Speed Manufacturers must specify the maximum safe speed for all sizes of abrasive wheels. This must be indicated on the plate located on the side of the wheel, as shown in the image below. Maximum safe speed Do not fit a wheel that is larger than the one designed to fit the machine or increase the spindle speed. This is dangerous because it will cause the wheel to run at a higher surface speed than it is designed for. This may cause the wheel to fly apart. When using a grinding machine, make sure that: The work rest is properly adjusted. The wheel guard is securely fitted. The machine/wheel speed combination is correct. You will examine a number of characteristics of grinding wheels, such as: Wheel speed Wheel rotation Abrasives. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 194 of 498 Grinding Wheel Direction of Rotation The direction of rotation of the grinding wheel should be downwards towards the work rest, with the spindle rotation, as shown below, tending to tighten the nuts holding the wheels on the spindle. When you face the machine, the spindle on the left should have a left-hand thread so that the nut tightens anti-clockwise. Wheel direction of rotation The spindle on the right should have a right-hand thread so that the nut tightens clockwise. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 195 of 498 Abrasive Wheel Grinding Conditions When using a grinding machine for off-hand grinding, several conditions may develop on the surface of the wheel, such as: loading glazing grooving. These conditions may impair the effectiveness of the grinding machine. Bench grinder 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 196 of 498 Grinding Wheel Loading In loading, small particles of the material being ground become embedded in the spaces between the grains of the wheel. The surface of the wheel becomes clogged or loaded, reducing its cutting efficiency, as shown in the image below. Loading is the result of using the wrong type of wheel for the material being ground. Use a wheel with comparatively wide spacing of the grains for grinding soft, ductile materials. The wide structure allows more space for the chips to form. Review the specification of the wheel by referring to the manufacturer’s handbook. Loading 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 197 of 498 Grinding Wheel Glazing Glazing, as shown below, is caused by grinding hard materials on a wheel that has too hard a grade of bond. The abrasive particles become blunt from cutting the hard material, and the bond is too firm to allow them to break off. The wheel loses its cutting efficiency. Glazing can be prevented by referring to the manufacturer's handbook and selecting a wheel with a softer grade of bond. Glazing of the surface 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 198 of 498 Grinding Wheel Grooving Grooves on the surface of the wheel are caused by pressure being applied in one position. It can be prevented by moving the work across the full face of the wheel. Avoid grinding on the outside edges of the wheel, as this results in rapid wear and causes a curved surface on the wheel, as shown below. Grooving The conditions of loading and glazing are caused by using the incorrect type of wheel for the material being ground. Grinding machines set up for general purpose work have wheels selected with a grade of bond, abrasive grain size and structure that allow a wide range of general work and material variations. Use only the correct wheel for the material that is being ground, and never attempt to perform heavy, rough grinding on a small bench grinder set up for sharpening cutting tools. Dedicated grinding machines may be tagged, as shown below. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 199 of 498 Tagged dedicated grinding machine 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 200 of 498 Dressing and Truing the Grinding Wheel Abrasive wheels that develop loading, glazing or grooving must be trued or dressed to restore them to full operation. The dressing tool shown below is used to do this. Dressing is removing material from the cutting face to clean it or expose new abrasive particles on the cutting surface. Truing a wheel is removing material from the cutting face to square up the surface of the wheel and make it concentric with the axis. Loading and glazing require dressing. Out-of-round and grooved wheels require truing. Dressing a wheel face should also true the wheel and vice versa: Truing a wheel also dresses the face. Dressing a wheel face 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 201 of 498 Dressing tool technique Regular light dressing and truing are better than allowing a wheel to become badly out of round, which then requires severe dressing. Note: The abrasive dust produced by dressing an abrasive wheel is harmful. If the machine is fitted with a dust extractor, turn it on before starting to dress the wheel. If not, wear a suitable respirator as well as protective goggles. Selecting a Fixed Grinder Make sure you select the right type of machine for the work to be performed. Dressing a casting or other heavy work requires a floor type pedestal grinder. Tool sharpening is generally done on a smaller bench type machine. Check that the wheel mounted on the machine is suitable for the type of work to be performed. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 202 of 498 Protective Equipment (Grinding) The wheel guards must be securely fixed in place, and the work rest must be adjusted and firmly clamped as close to the wheel face as possible. Wear suitable clothing, such as: Close-fitting overalls buttoned up to the neck and with buttoned sleeves Safety goggles. When grinding heavy work, you should also wear a heavy leather apron, safety boots and leather gloves. The area around the machine should be well lit and kept clear, as shown below. Wear the required PPE 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 203 of 498 Grinding Operations When you are using an off-hand grinding machine, stand comfortably so that you are supported evenly on both feet and can apply the required pressure to the work against the wheel. You should not be in a position that would allow your hands to contact the wheel if you or the work slipped. Never attempt to maintain the cutting action by forcing the work against the wheel. Make sure the work is well supported by the work rest, as shown below: Flat or sheet work should be held in a way that prevents hammering or vibration. Raise the back part of the work slightly so that the cutting action of the wheel holds the work down on the rest. Never hold the work to the wheel at an angle or position that allows it to become jammed between the wheel and the work rest. Workpiece position 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 204 of 498 When using the abrasive wheel: Move the work across the face of the wheel to keep wear even. Avoid grinding on the corners of a wheel. Never use the side of an abrasive wheel unless the machine and wheel have been designed for this purpose. Side pressure may break the wheel or the work may become jammed between the side of the wheel and the wheel guard. An example of a machine designed for side grinding is shown below. Side grinding for tipped tools 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 205 of 498 Grinding Small Work The grinding process generates heat, so you should: Hold small articles in a suitable fixture or with a pair of pliers, as shown below. Have a container of cool, clean water close by to cool the work as it becomes heated. Never quench work made from high-speed steel directly in cold water, as cracking of the edge may result. Allow the work to cool in air. Grinding a small workpiece 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 206 of 498 Sharpening Cutting Tools When sharpening cutting tools, hold them so that the: Grinding action of the wheel transmits any heat generated onto the solid part of the tool Air flow carried around by the wheel is directed onto the cutting edge, helping to prevent overheating Grinding action is down onto the cutting edge to produce a burr-free surface. The illustration below shows how a centre punch is sharpened with these three points applied. Sharpening a centre punch Never try to force the abrasive wheel to cut by applying excessive pressure to the work or by bumping or jogging the work against the wheel. Heavy or uneven pressure will cause the wheel to heat up unevenly and could cause it to crack. To remove material more rapidly, use a coarser grit wheel. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 207 of 498 Drilling Machines Bench Drill You need a basic understanding of the functions and uses of different drilling machines to select the most appropriate and efficient machine for your work. Some features of the bench drill are: They are usually belt driven. They have a drill shank capacity of 13 mm or less. For general purposes, their spindle speeds range from a few hundred revs per minute to a few thousand revs per minute. Hand (manual) feed of the drill bit is generally employed. For drilling small holes, this hand feed is made sensitive by balancing the weight of the spindle with a return spring. Bench drilling machine The work piece can be held in a machine vice, which in turn can be attached to the machine table. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 208 of 498 Upright (Column) Drill Press Some features of the upright drill press are: It is checked for plumb (perfectly vertical) and then bolted to the floor. It is belt or gear driven. It may have a drill shank capacity of 65 mm. Special machines may have much larger capacities. It offers a very wide range of spindle speeds. Dial or lever selection of the spindle speed is often available. It may include a complex work table that can swivel and tilt. On large machines, the work table may be operated by a separate elevating motor. Column drilling machine 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 209 of 498 Column drill Drill Speeds Errors in speed calculations produce the following results: Too fast a cutting speed results in the cutting edges of the drill dulling rapidly and requiring frequent regrinding. Too slow a cutting speed generally results in a broken drill. A wide range of drills and drill sizes are used to cut various metals; an equally wide range of speeds are required for the drill to cut efficiently. The most efficient drilling speed depends on many variables, such as: Type and hardness of the material Diameter and material the drill is made of Depth of the hole Type and condition of the drill press Efficiency of the cutting fluid employed Accuracy and quality of the hole required Rigidity of the work set-up. Of these points, the most important variables are the type of work materials and the diameter of the drill. References to the speed of a drill describe the cutting speed in surface feet per minute rather than drill revolutions per minute, unless otherwise stated. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 210 of 498 Cutting Speeds The cutting speeds for various materials are listed below. These speeds are for general purpose cutting and finishing. Other special operations usually have different cutting speeds. Drill Speed Table Drill Diameter (mm) Drill Speed (rpm) Drill Diameter (mm) Drill Speed (rpm) 1 9700 11 880 2 4850 12 800 3 3230 13 740 4 2420 14 690 5 1940 15 640 6 1610 16 600 7 1380 17 570 8 1210 18 530 9 1070 19 510 10 970 20 480 Note: Cutting speed varies depending on the material from which the drill is made and the material being drilled. A small-diameter drill should be run at a faster speed than a large-diameter drill when cutting the same metal. Drills should be run faster when cutting soft metals, such as aluminium, than when cutting hard metals, such as mild steel. As more materials of different hardness become involved in metalwork projects, there is a constant need to change the speed of the press drill spindle. Attempting to drill at too fast a speed causes drill bits to overheat, become blunt and damage the cutting edges. Drilling too slow easily causes breakage of a small-diameter drill under pressure. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 211 of 498 Safe Working Practices When Changing the Spindle Speed Switch the power off at the machine isolator switch. Do not rely only on the machine itself being switched off. Remove the safety guard over the driving pulleys. Loosen the tensioner bolts. Move the V-belt to the required position. Consult the table of speeds attached to the drill to find the correct belt position to suit the drill size and the metal. After moving, the belt must be horizontal and in the same relative position on the pulley at each end. If the belt is fitted on the slant, it may be stretched and badly worn. Ensure the tensioner bolts are firmly tightened and replace the safety guard. Drill Feeds Although small-diameter drills are run at a faster speed, they must be fed slowly into the metal because they are easily broken if too much pressure is applied. Larger-diameter drills can be fed faster because they are stronger. Whether large or small in diameter, it is important that the drill is kept cutting and not allowed to just rub, or it will quickly overheat and become blunt. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 212 of 498 Drill Lubricants A suitable lubricant should be used to keep the drill cool and to assist swarf escaping up the flutes of the drill. Lubricants suitable for use with a range of metals are set out below: Mild steel — soluble oil High-carbon steel — soluble oil Copper and brass — kerosene Cast iron — best worked dry Aluminium — kerosene Stainless steel — soluble oil. Lubricant 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 213 of 498 Drilling Procedures Drilling a Part These are the key steps. 1. Select the correct size drill. 2. Check the speed. 3. Hold work securely. 4. Check that the drill hole is on-centre. 5. Feed the drill slowly through the metal. 6. Clean up. Safety Check When Drilling Wear eye protection. Only one person should operate the press drill. Do not hold metal in your bare hand when drilling. When drilling holes of a diameter greater than 10 mm, you should first drill a pilot hole. The pilot hole should be approximately the web diameter of the final hole. A build-up of heat can damage the drill. This may be prevented by using a suitable lubricant, such as soluble oil for drilling steel. Before use, inspect electrical cords and air hoses and the tools themselves for damage. Check the tool for correct operation. If a tool or its cord or hose is damaged or it does not operate properly, tell your supervisor. Be sure you understand your employer's rules about damaged or unserviceable tools. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 214 of 498 Electric Power Tools Electric Power Tools (Wired and Cordless) The various types of electric power tools include electric drills, screwdrivers, impact wrenches, saws, grinders and buffs. Most of these are powered by mains power, but some drills or screwdrivers are battery powered and are known as cordless power tools. Electric drills, as shown below, are available in various sizes depending on the required use, power and chuck size. Some drills have variable speeds, which makes them useful for driving drills, rotary files and so on. Cordless drills are a practical alternative and are very useful when power is not conveniently available. In order to use screwdriver bits, it is preferable to use dedicated power screwdrivers or at least a drill with variable torque, speed and reverse. Electric drills 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 215 of 498 Bandsaws Bandsaws are useful cutting tools but are not forgiving of careless use. Ensure the correct blade for the material being cut is installed. Ensure the blade guide guard is adjusted to just clear the work piece. Keep hands well clear of the blade. Do not attempt to cut round stock radially or axially unless the material is clamped in a Vsection jig. Always wear eye protection when using a bandsaw. Ensure power is isolated before making any adjustments to a bandsaw. Bandsaw 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 216 of 498 Hand Grinders Hand grinders are powered either electrically or pneumatically; they are similar in shape. Safety precautions must be observed at all times. There are three types of hand or portable grinders: Angle grinders Straight grinders Die grinders (sometimes known as pencil grinders). Angle grinder Straight grinder 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 217 of 498 Die (pencil) grinder A great variety of electric grinders, buffs and cut-off machines are also available. Their power, size and speed should be matched to the application they are used for. Electric Nibblers and Jigsaws Electric nibblers and jigsaws are used to cut metal. A typical nibbler is shown below. Electric nibbler 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 218 of 498 Pneumatic Power Tools Pneumatic Tools (Compressed Air Tools) Pneumatic tools are powered by compressed air and include chippers, drills, hammers and sanders. Several dangers may be encountered in the use of pneumatic tools. The main one is the danger of getting hit by one of the tool's attachments or by some kind of fastener the worker is using with the tool. Eye protection is required and face protection is recommended for employees working with pneumatic tools. New resource Pneumatic tools – examples 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 219 of 498 Pneumatic Power Tools Advantages Pneumatic power tools are usually more compact than electric tools. Speed can be varied by adjusting the supply of air pressure. Higher rotational speeds are useful for small grinders and polishing stones. Safety is improved, especially where moisture is present and in a flammable environment. Pneumatic power is especially useful for riveting. Some common pneumatic tools used in the aviation environment include: Diamond Saws Diamond saws are used for cutting composite materials during fabrication. High-Speed Pneumatic Grinder A high-speed pneumatic grinder like the one shown below is used to remove material from large and cumbersome items accessible only with portable equipment. High-speed pneumatic grinder 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 220 of 498 Compressed Air Supply Compressed air is piped around workshops: To power pneumatic tools For use in pressure cleaning equipment For use in paint spraying equipment. Airline filters/regulators can be installed in the plumbing to ensure that air passing through tools is dry and permits adjustment of the air pressure when required. A typical regulator is shown below. Airline filter/regulator 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 221 of 498 Air Hose Hose and hose connections used for conducting compressed air to utilisation equipment must be designed for the pressure and service to which they are subjected. Pneumatic power tools must be secured to the hose or whip by some positive means to prevent the tool from becoming accidentally disconnected. Safety clips or retainers must be securely installed and maintained on pneumatic impact (percussion) tools to prevent attachments from being accidentally expelled. Do not exceed the manufacturer's safe operating pressure for hoses, pipes, valves, filters and other fittings. Do not use hoses for hoisting or lowering tools. Noise is another hazard. Working with noisy tools, such as jackhammers, requires proper, effective use of hearing protection. When using pneumatic tools, you must check to see that they are fastened securely to the hose to prevent them from becoming disconnected. A short wire or positive locking device attaching the air hose to the tool serves as an added safeguard. A safety clip or retainer must be installed to prevent attachments, such as chisels on a chipping hammer, from being unintentionally shot from the barrel. Screens must be set up to protect nearby workers from being struck by flying fragments around chippers, riveting guns, staplers or air drills. Compressed air guns should never be pointed towards anyone. Users should never ‘dead-end’ an air gun against themselves or anyone else. Compressed air hose 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 222 of 498 Compressor System Care Contaminants in the Compressor System The most common problem is water in compressed air. All air contains a certain amount of moisture and impurities, which can cause problems when the moisture condenses in the air. Condensed water vapour and dirt left in the air line may result in the following problems: Sluggish tool operation and more frequent repair and replacement of parts Poor results in spraying and other types of finishing work Washing away of required lubricants Freezing of moisture left in lines exposed to cold weather, obstructing air flow. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 223 of 498 Compressed Air Guidelines and Precautions You must learn to distinguish compressed air pipes from other pipes. Compressed air is very dangerous when used for anything but the correct purpose. The following section will outline some simple guidelines and precautions to remember when using pneumatic systems or tooling. Prior to operating compressed air: Clear any dirt off the nipple before connecting the air hose to the tool - this will ensure a good connection and reduce the risk of disconnection. Use the proper size air hose and fittings to keep air pressure at a maximum throughout the entire line. Most manufacturers recommend 90 psi at the tool. To protect the air hose from damage, move it out of the way of vehicles so that it does not get run over. Also, be sure not to drag hoses around sharp corners. Always check that the hose and connections are not damaged. Do not use any pneumatic tool which has a faulty operating valve or governor. Check that the exhaust air ducts on the tool are clean and that the casing is not damaged. During the use of compressed air or pneumatic tools: Never use compressed air to clean your clothes or hair. Eye damage or ruptured ear drums result from doing this. Never direct compressed air at another person. It can cause serious injury or death. Use rubber gloves if components have to be cleaned with compressed air. Never blow down a bench or machine tool with compressed air. It could spread metal filings and chips for some distance. Before connecting or disconnecting any pneumatic tools (including changing an air tool), always turn off the air supply. Use the valve or power switch and never kink the hose as a shortcut. This may damage or rupture the air hose. Follow safety procedures similar to those for electric power tools in holding, starting, working with, putting down and disconnecting air (pneumatic) tools. 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 224 of 498 The Riveting Gun and Set The Rivet Gun You will use a riveting gun in combination with a set or snap suited to the head of the rivet being driven. Sets or snaps are available to suit the various raised head shapes or flush rivets and in various lengths or offsets to assist accessibility. The set is fitted into the barrel, where it is retained by a coil-retaining spring. The retaining spring prevents forced ejection of the set, which could cause injury and damage. When the trigger is pressed, compressed air is directed in rapidly alternating directions to a piston which forcibly strikes the set. The repetitive blows drive the rivet against the bucking bar (or dolly), thus compressing the rivet tail. Rivet guns are available in a range of sizes and shapes; these can be divided into two basic categories: Fast-hitting, short-stroke guns which produce light blows Guns with long strokes that produce heavy blows. A number of handle styles appear on both types of guns. The pistol grip and offset handle are the most popular styles, with the push-button type available for special applications. Rivet gun 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 225 of 498 Rivet sets are available for different rivet sizes and head styles. It is important to select the correct set for the job at hand to prevent damage to the rivet or the material to be fastened. Never aim a rivet gun at any person. Rivet sets Bucking bars (dollies) are held against the tail of the rivet; they form what is termed the shop head when the rivet gun and set is operated. They are available in various sizes and shapes, according to rivet size and access to the tail. Bucking bars (dollies) 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 226 of 498 Squeeze Riveting When there are a large number of rivets to be driven along the edge of a sheet or in a stringer, a squeeze riveter can reduce the time required to produce a far more uniform row of rivets than can be driven by a rivet gun. A squeeze riveter consists of a pair of jaws: one stationary and the other moved by a piston in an air cylinder. A dolly with a cup that fits the rivet head is put into the stationary jaw, and a flat dolly is fitted to the movable jaw. When the handle or trigger is operated, the jaws are squeezed together and form the shop head. The dollies are available in various forms, and the distance between the closed jaws is adjustable. Squeeze riveters 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 227 of 498 Soldering Irons The Soldering Iron In general, soldering may be described as either soft or hard soldering, depending on the type of material to be soldered. By definition, the difference between soft soldering and hard soldering (silver soldering and brazing) is the temperature required to melt the filler metal. If the required temperature is above 800 °F, the process is termed hard soldering, and the use of a blowtorch is required. Soft soldering is usually carried out using soldering irons. The tip or head of the soldering iron is made of copper and may be heated electrically or by flame; however, electrical soldering irons are the most common and convenient. Soldering irons are available in many different heat ranges, as are tips in varying shapes and forms according to the particular work piece and heat range required, from sealing up seams in fluid containers (oil coolers, radiators, etc.) to soldering intricate electronic components. Common soldering tips (coppers) for larger work Electric soldering iron 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 228 of 498 Soldering Stations A soldering station combines the soldering hand tool and tip with a tip cleaning sponge and iron holder in one compact package. It also includes a method of heat regulation to change tip temperature. Varying the tip temperature enables pinpoint matching of equipment to application. By controlling or limiting tip temperature, the soldering station can also facilitate soldering without damage to heatsensitive assemblies. Soldering stations 2023-11-24 B-07b Maintenance Practices CASA Part 66 - Training Materials Only Page 229 of 498