Trade Resources Industry Knowledge A Table Saw or Sawbench Is a Woodworking Tool Consisting of a Circular Saw Blade

A Table Saw or Sawbench Is a Woodworking Tool Consisting of a Circular Saw Blade

A table saw or sawbench is a woodworking tool consisting of a circular saw blade, mounted on an arbor, that is driven by an electric motor (either directly, by belt, or by gears). The blade protrudes through the surface of a table, which provides support for the material, usually wood, being cut. In a modern table saw, the depth of the cut is varied by moving the blade up and down: the higher the blade protrudes above the table, the deeper the cut that is made in the material. In some early table saws, the blade and arbor were fixed, and the table was moved up and down to expose more or less of the blade. The angle of cut is controlled by adjusting the angle of blade. Some earlier saws angled the table to control the cut angle. Types of table saws There are four general classes of table saws: benchtop table saws, contractor table saws, cabinet table saws and hybrid table saws. Benchtop table saws Benchtop table saws are lightweight and are designed to be placed on a table or other support for operation. They commonly have direct drive (no v-belt or pulleys) from a universal type motor. They can be lifted by one person and carried to the job location. These saws often have parts made of steel, aluminum and plastic and are designed to be compact and light. Benchtop table saws are the least expensive and least capable of the three major types; however, they can offer adequate capacity and precision for many tasks. The universal motor is not as durable or as quiet as a brushless AC motor, but it offers more power relative to its size and weight. The top of a benchtop table saw is narrower than those of the contractors and cabinet saws, so the width of stock that can be ripped is reduced. Another restriction results from the top being smaller from the front of the tabletop to the rear. This results in a shorter rip fence, which makes it harder to make a clean, straight cut when ripping. Also, there is less distance from the front edge of the tabletop to the blade, which makes cross cutting stock using a mitre more difficult (the mitre and/or stock may not be fully supported by the table in front of the blade). Benchtop saws are the smallest type of table saw and have the least mass, potentially resulting in increased vibration during a cut. Contractor table saws Contractor table saws are heavier, larger and have an attached stand or base, often with wheels. The motor hinges off the rear of the saw and drives the blade via one, or occasionally two, belts using a 1 to 2 hp (750 to 1500 W) induction type motor. This is the type often used by hobbyists and homeowners because standard electrical circuits provide adequate power to run it, and due to its low cost. Because the motor hangs off the rear of the saw on a pivot, dust collection can be problematic in comparison with a cabinet saw. Cabinet table saws Cabinet table saws are heavy (using large amounts of cast iron and steel) to minimize vibration and increase accuracy. A cabinet saw is characterized by having a closed (cabinet) base. Cabinet saws usually have induction motors in the 3 to 5 hp (2 to 4 kW) range. For home use, this type of motor typically requires that a heavy-duty circuit be installed (in the US, this requires a 220V outlet). The motor is enclosed within the cabinet and drives the blade with three parallel v-belts. Cabinet saws are heavier and offer the following advantages over contractor saws: heavier construction for lower vibration and increased durability; a cabinet-mounted trunnion (the mechanism that incorporates the saw blade mount and allows for height and tilt adjustment); improved dust collection due to the totally enclosed cabinet and common incorporation of a dust collection port. In general, cabinet-mounted trunnions are easier to adjust than table-mounted trunnions. The American-style cabinet saws generally follow the model of the Delta Unisaw, a design that has evolved since 1939.[citation needed] Saws of this general type are made in the USA, Canada and China. These saws are characterized by a cast iron top on a full-length steel base, square in section, with radiussed corners. Two 3/8" deep by 3/4" wide miter slots are located parallel to the blade, one to the left of the blade and one to the right. The most common type of rip fence mounted to this type of saw is characterized by the standard model made by Biesemeyer. It has a sturdy, steel T-type fence mounted to a steel rail at the front of the saw. It has replaceable laminate faces. American cabinet saws are normally designed to accept a 13/16" wide stacked dado blade in addition to a standard saw blade. The most common size of blade capacity is 10" in diameter. The blade arbor has a diameter of 5/8". American saws normally include an anti-kickback device that incorporates a splitter, toothed anti-kickback pawls and a clear plastic blade cover. American style saws have an easily replaceable insert around the blade in the table top. This allows the use of zero-clearance inserts, which greatly reduce tear out on the bottom of the workpiece. It is common for this type of saw to be equipped with a table extension that increases ripping capacity for sheet goods. American style table saws are commonly available with the option of left or right tilt blade capability. While relatively simple in design, these saws are highly evolved and capable of efficient and precision work. European-style cabinet saws are often more complex and modern in design compared to American types. They often are equipped with a sliding table to make cross cuts easier and safer than by the use of an American style mitre gauge. Unless modified for the American market, European table saws are not equipped to allow the use of a stacked dado blade set (this is due to safety laws in European markets). Rip fences on European saws tend to be of lighter construction and less smooth in operation compared to American cabinet saws. European cabinet saws are often available in multi-purpose tool configurations that can offer jointer, planer, shaper or boring features. The blade arbor typically has a diameter of 30mm, though for the American market a 5/8" arbor is commonly available as an option. Note that American woodworkers are likely to use a stacked dado blade to cut dados (square sectioned grooves) where European woodworkers might use a shaper or other tool for this task. European cabinet saws often incorporate a riving knife to prevent kickback. Riving knives differ from American style splitters in that they rise and fall with the blade (splitters are fixed in place without regard for the height that the blade is adjusted to). European cabinet saws often offer as an option a scoring blade, which is a second, smaller diameter blade mounted in front of the regular saw blade. The scoring blade helps reduce splintering in certain types of stock, especially laminated stock. Hybrid table saws Hybrid table saws are designed to compete in the market with high-end contractor table saws. They offer some of the advantages of cabinet saws at a lower price than traditional cabinet saws. Hybrid saws on the market today offer an enclosed cabinet to help improve dust collection. The cabinet can either be similar to a cabinet saw with a full enclosure from the table top to the floor or a shorter cabinet on legs. Some hybrid saws have cabinet-mounted trunnions and some have table-mounted trunnions. Hybrid saws tend to be heavier than contractor saws and lighter than cabinet saws. Some hybrid saws offer a sliding table as an option to improve cross cutting capability. Hybrid saw drive mechanisms vary more than contractor saws and cabinet saws. Drive mechanisms can be a single v-belt, a serpentine belt or multiple v-belts. Source: en.wikipedia.org

Source: http://en.wikipedia.org/wiki/Table_saw
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Table Saw
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