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The design and shape of cordless power tools makes then fit into areas where corded power tools will not. In many cases, this leads to a sacrifice of turning strength from the motor. Dewalt power tools makes larger voltage cordless power tools to deliver more power for your job. Dewalt cordless power tools are the ones most often selected by professionals. Their dependability and ability to perform heavier work than most of the other lines of cordless tools is the reason for this. When doing repetitive work like hanging sheet rock, drill bits for driving the screws holding the sheet rock in place, tend to wear out and need replacement often. The quick-change heads of Dewalt power tools make this an easy task to accomplish with minimum slowing of the work being performed. Dewalt power tools offers a nice line of cordless screwdrivers and variable speed drills. The power ratings range from 7.2-volt motors up to 24-volt motors delivering the type of power you need. A variable speed drill is used to make a variety of different size holes from very tiny ones used to enable nails and screws to be driven without splitting the wood to large ones used for installing door knob assemblies. When using a variable speed drill, start your drilling slowly to allow the bit time enough to get firmly seated in the hole. This will lessen the chance of the bit jumping when higher speeds are applied which might cause you to drill something you did not want to have drilled. Dewalt power tools offer a full range of both corded and cordless tools. Their durability and easy ability to change accessories makes them highly desired for professionals. Dewalt power tools deliver in work conditions where other power tools fail. The only drawback I can see to this magnificent line of cordless tools is their weight. Having larger voltages to deliver more power means larger battery packs and larger motors as well. If you have to use one of these heavy cordless power tools all day, you will feel like you have done an intensive workout. Because this is a superior product, you can expect to pay a superior price for it as well. While you will see sales for the combo packs available in store ads, you may notice that these are the lighter weight tools. They will perform the work desired in most situation, but for the really heavy duty applications the heavy duty power tools will command a heavy duty price tag. Repairing Your Own Machine Components Thomas Yoon 1acb Many industrial concerns have workshops of their own. For the repair of worn shafts, the lathe machine is excellent. Keyway slots can be machined by using a milling machine, while a shaping machine can do machining of large flat areas. A drilling machine does drilling of holes. A skilled Maintenance Engineer should know how to use all these machines in order to make his own repairs in a safe manner. Very often he has to supervise machinists. The information below should be useful for that purpose. Lathe Machine The lathe machine uses a single-point-cutting tool for a variety of turning, facing, and drilling jobs. Excess metal is removed by rotating the work piece over the fixed cutting tool to form straight or tapered cylindrical shapes, grooves, shoulders and screw threads. It can also be used for facing flat surfaces on the ends of cylindrical parts. The work piece is clamped onto a horizontal rotating shaft by a 3-jaw or 4-jaw chuck. The latter chuck can be used to cut off-centered cylinders. The rotating horizontal spindle to which the chuck is attached is usually driven at speeds that can be varied. The cutting tool is fixed onto a tool rest and manipulated by hand. It can also be power driven on straight paths parallel or perpendicular to the work axis. This is useful for screw cutting. Internal turning known as boring results in the enlargement of an already existing hole. The holes are more accurate in roundness, concentricity, and parallelism than drilled holes. A hole is bored with a single-point-cutting tool that feeds along the inside of the work piece. Shaping Machine The shaping machine is used to machine flat surfaces, grooves, shoulders, T-slots, and angular surfaces with single-point tools. The cutting tool on the shaper oscillates, cutting on the forward stroke, with the work piece feeding automatically toward the tool during each return stroke. Drilling Machine The drilling machine is used to cut holes in metal with a twist drill. By changing the cutting tool, they can be used to do reaming, boring, counter boring, countersinking, and threading. Milling Machine The milling machine uses a rotating cutting tool to cut flat surfaces, grooves, and shoulders, inclined surfaces, dovetails, and T-slots. Cutters of many shapes are changed to cut different grooves. Cutting Tools Metal-cutting tools are classified as single point or multiple point. The lathe and shaping machine use single point cutting tool while the milling and drilling machines use multiple-point-cutting tools. Metal is cut either by moving the work piece like in the lathe or by moving the tool like in the shaping machine, drilling or milling machine. Clearance angles must be provided to prevent the tool surface below the cutting edge from rubbing against the work piece. Rake angles are often provided on cutting tools to cause a wedging action in the formation of chips and to reduce friction and heat. Tool Materials In order to remove chips from a work piece, a cutting tool must be harder than the work piece and must maintain a cutting edge at the temperature produced by the friction of the cutting action. Carbon Steel Carbon steel tools even though comparatively inexpensive tend to lose cutting ability at temperatures around 400 degree F (205 degree C). High-Speed Steel High-speed steel, containing 18 percent tungsten, 4 percent chromium, 1 percent vanadium, and only 0.5 to 0.8 percent carbon, permits the operation of tools twice or three times the speeds allowable with carbon steel Cast Alloys Cast-alloy cutting-tool materials containing cobalt, chromium, and tungsten are effective in cutting cast iron and retaining their cutting ability even when red hot. Cemented Tungsten Carbide The hardness of Tungsten Carbide approaches that of a diamond. Tungsten carbide tools can be operated at cutting speeds many times higher than those used with high-speed steel. Oxides Ceramic, or oxide, tool tips consist primarily of fine aluminum oxide grains, which are bonded together. These are very hard. Cutting fluids An overheated tool can become blunt and soft very fast. Therefore very often, cooling fluids cools the cutting points of the tool. This serves to lubricate and cool. Water is an excellent cooling medium, but it corrodes ferrous materials. Sulfurized mineral oil is one of the most popular coolants as it can both cool as well as lubricate. The sulfur prevents chips from the work from melting on to the tip of the tool. As Easy As Blockbuster Guarantee Find the Best Tools for Garden, Garage, Industry and Home. Widest Range of Quality Tools. /www.free-marine.com/linknortherntool.htm target=_blank>http://www.free-marine.com/linknortherntool.htm>Best Tools About the AuthorMany years of working experience in Marine, Facilities, http://www.aaarticles.com/article9238.html | ||||||||||||||||||||
