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Copyright © A.F.Billington 2022. All rights reserved.
Mr BILLINGTON
Material Wasting - Powered Saw
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The introduction of the electric motor removed much of the physical effort required when sawing material, although powered versions using steam or water existed for a long time before
The circular saw uses a rotating flat bladed disc attached to an electric motor that spins up to 9000~ rpm. A wide range of blades can be used for differing cuts and materials, as well to alter the kerf (channel) size cut. When attached to a fixed bed it is known as Table Saw and can be used to cut straight, relatively accurate lines through adjustment of the 'fence'. The height of the blade can be adjusted as well as the angle up to 45°. Due to the material being held and moved by the operator there is a greater risk of injury when using a table saw than a circular saw
Many other variants exist for different jobs including portable versions
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Bandsaws use a continuouslooped ripsaw blade that rotates on an electric motor around two wheels. The blade is held under tension and rotates in a clockwise direction. The exposed portion (throat) of the blade is above the machine table and is held between a guide which can moved up or down depending on the size of the work piece. Only the minimum amount of blade should be exposed when in use to protect the user and ensure greater accuracy. A range of blades can be used depending on the material to be cut with varying teeth densities (TPI) to machine through wood, metal & plastic. A very thin kerf can be achieved with a bandsaw due to the thickness of the blade which is typically 1.6mm
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A Scrollsaw is a powered reciprocating ripsaw with a fine short blade, much the same as a manual coping saw. Its name is derived from the intricate scrollwork art they were used for when pedal powered. Much like a coping saw, the blade can be removed easily and fitted through drilled holes to make internal cuts in the material. Often the speed is adjustable and the bed can be rotated up to 45°. The 'throat', as with the bandsaw, is the measurement from the top of the exposed blade to the bed and is the material limitation of the machine. As the blade has a very low profile and cuts with minimal kerf they are used for very intricate curved design work such as Intarsia
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Variations exist of each of the three powered saws above, but their operation covers the main cutting methods; disc blade, belt blade & saw blade. Advancements in battery technology have allowed for portable versions of powered saws to become prevalent in industry, often with equivalent capability;
- A jigsaw works much like a scroll saw but without the limitation of a fixed bed allowing for work on larger materials but with less accuracy. Often they are fitted with a laser guide to improve this
- The Mitre saw is a circular ripsaw fitted to a vertical swing arm. The angle of cut can be precisely altered to form angles up to 45° & compound mitre saws allow further adjustment by tilting the blade
- A circular saw functions in the same way as the table saw above but without the fixed limitations of a work bed. Depth can be quickly adjusted by adjusting the base plate and as with the Mitre, the blade is concealed in a guard until it contacts the material for safety
The portability of these powered saws is largely due to the recharagable battery. Originally, NiCAD batteries were used in most power tools but these were prone to a 'memory' which meant they deteriorate quicker and could only deliver a limited amount of current. Lithium-Ion batteries have greatly improved the durability and power output of portable tools, with many manufacturers moving towards interchangeable batteries across their range of products
DRILLING