Class: Building Maintenance Teacher: Mr Roseus Assignment 1 Please read and answer the following questions: Jigsaw saw The jigsaw sometimes called a saber saw or bayonet saw is the best power saw for making curved or irregular cuts. Carpenters use a jigsaw to notch wood deck boards to fit around a post. Cabinet installers use it for fitting cabinets and for cutting large holes in countertops. Siding installers use a jigsaw to cut siding to fit around curved windows. Unlike the saw discuss in previous sections, the jigsaw has a straight blade. Teeth are formed into one edge, and instead of spinning the blade moves up and down. Fitted with a suitable blade, a jigsaw will cut metal, wood, plastic and many other materials. It is often used instead of a hacksaw to cut angle iron and various kinds of metal or plastic pipe. Familiarize yourself with your saw’s owner’s manual. This will include specifics regarding your jig saw’s components and features. Before operating a jig saw, you should gear up in the appropriate personal protective equipment. This includes a pair of shatter-resistant goggles to protect from dust and chippings and a face mask to protect from breathing in particles. Contrary to what some people may believe, gloves aren’t necessary when operating a jigsaw. In fact, they can actually increase the risk of injury, as the material may catch in the reciprocating saw, pulling your hand into the blade. Fit an extraction bag to the jigsaw. This will collect most of the dust and keep the work area clear while cutting. A selection of blades can be fitted to a jig saw and the best (and safest) blade for the job depends on factors including what material is being cut. Frequently check your jig saw’s blade on a regular basis, and when necessary, sharpen or replace it. Operating a dull jig saw increases the risk of kickbacks (which is the primary source of table saw accidents). Because they contain small and weak blades (compared to other power tools), jig saws are somewhat sporadic. Experience and knowledge go a long way in keeping control while operating the jig saw and will reduce the risk of injury. Keep the blade and surrounding components of your jigsaw well lubricated to ensure clean cutting. Do not attempt to force the jig saw through hard, stubborn material. If the blade won’t cut, reverse it and try again. Jig saws are not intended for use in wet environments. Electrical power tools such as jig saws may shock the operator when exposed to water or even airborne moisture. This is why it’s critical that jig saws are only operated in a dry, covered environment. Jig saws should only be operated when plugged into a RCB circuit breaker to reduce the risk of electrical fire and electrocution. Circuit breakers are designed to cut power when the connected devices are pulling too much electricity; thus, protecting against electrical failure. The only exception to this rule is the use of a portable jig saw with a dedicated/rechargeable battery. The different parts and features of a jigsaw lets you cut not just wood, but also materials such as metal, plastic, and even ceramic. Depending on the type of jigsaw and blade you have, you can also do bevel cuts and plunge cuts as well, in addition to straight and scrolling cuts. Finally, you may have a jigsaw that is corded or cordless, and that means you may be either working with a cord, or a more portable power pack. 1. The Jigsaw Blade The business end of the jigsaw is the blade. The jigsaw moves the blade in a reciprocating motion, or in a rapid up and down motion when the tool is held horizontally. There are many types of jigsaw blades available on the market today that lets you use the tool on a wide variety of materials. General purpose jigsaw blades have teeth that point upward, which means that the tool cuts on the upstroke. There are also reverse teeth jigsaw blades that let the tool cut on the downstroke instead, which can lead to a better cut finish if you use the jigsaw on a work piece with the good side facing up. There are also blades that are designed to grind, instead of cut. These carbide or diamond grit blades are ideal for working with brittle materials like ceramic or glass. Finally, there are sharp pointed jigsaw blades that lets you do plunge cuts with the tool. Jigsaw blades generally come in lengths ranging from 3 ¼ inches to 4 inches. Heavy duty blades designed for hardwood may reach 6 to 7 inches long, and there are jigsaw blades designed to cut through wood and metal sandwiches that can reach 10 inches long or more. Jigsaw blades come with varying numbers of teeth, which will greatly affect the overall finish of the cut. Blades with a high TPI or teeth per inch count will generally leave a smoother finish, and will also give you a lower cutting speed. 2. Blade Clamp Mechanism The blade clamp mechanism secures the blade in the jigsaw and ensures that it stays aligned with the cutting line even at high speeds. Most jigsaws will come with one of the two most popular blade clamp systems. U- clamps, or Universal clamps, was the earlier standard and it comes with a retaining screw that requires you to get a screwdriver every time you need to change or remove a blade. The T-clamp, or multidirectional clamp, has a quick release mechanism that lets you change blades without having you reaching for your toolbox. Most blades will only fit one of these two clamp mechanisms. There are, however, jigsaws that have mechanisms that can take both types of blades. 3. Blade Guard Jigsaws will usually have a blade guard made of clear plastic or metal that is mounted at the front of the blade. Aside from helping to prevent accidents, the blade guard also helps deflect sawdust and debris thrown by the moving blade, which in turn helps keep them in a convenient area for your attached vacuum to pick up. 4. Blade Roller Guide Blade roller guides usually come in the form of two rollers that support the blade just above the shoe, in the same way that rollers on bandsaws help stabilizes the blade. Roller guides also help keep the thinner jigsaw blades from flexing and bending, which keeps them from prematurely breaking as well. Roller guides used to be a feature that only high-end jigsaw models carry. Nowadays, however, just about every mid-range jigsaw will come with a blade guide system. 5. Dust Collection Port Many jigsaws also come with a dust collection port that ejects dust and debris through and out of the back of the main body of the tool, if you connect it with a vacuum hose to a shop vacuum. A jigsaw with a dust collection feature is highly recommended if you are working with materials that release hazardous dusts, such as formaldehyde gas from MDF boards. On the other hand, a vacuum hose may impede the movement of your jigsaw, and could affect the precision of your freehand cuts. 6. Footplate Or Shoe The footplate or shoe of the jigsaw helps you keep the blade at the same angle throughout the entire cut. Most jigsaw footplates are adjustable as well, and you can position them to a desired angle to make bevel cuts of up to 45 degrees. Many adjustable footplates come with a built-in lever to unlock and relock the shoe into position. Some jigsaw shoes, however, require a screwdriver or wrench to release or relock a locking screw. The footplate may also come with rip fence slots that let you attach a fence guide or a parallel cutting guide to the shoe of the jigsaw. These guides let you cut parallel to the edge of a material, or alongside a clamped straightedge. You can also attach circular cutting guides similar to beam compasses that let you cut accurate circles or circular arcs at a certain radius. The footplate may also come with a protective overshoe that you can put on to prevent the tool from scratching delicate materials, such as glass or polycarbonate plastic. Some jigsaws also come with a splinter guard that goes over the footplate and leaves just a tight opening for the blade. These splinter guards help hold down the material and reduce splintering and tear-outs, which can be handy if you are working with melamine or veneered work pieces. 7. Handle The handle of the jigsaw helps you hold the tool while guiding it along the cut. Most jigsaws come with a top handle, or what is also called a bow handle or D-handle. These handles give you access to the trigger switch and lock-on button while also letting you use the tool with one hand. Some jigsaws also come with a barrel grip, which lets you hold the main body of the jigsaw as the handle of the tool. This lets you guide the tool with your hand closer to the footplate, and these can give you more accurate control of the jigsaw. Most barrel grip jigsaws also come with a second knob at the front which helps you hold it down – barrel grip jigsaws generally encourage you to use the tool with both hands. There are some jigsaws that also let you convert the tool between a barrel grip or a top handle configuration with the help of some attachments.