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A Band Saw is named after its cutting
implement, which is a narrow metal band wrapped tautly around two or
three wheels, like a belt. One edge of this band is serrated. When the
saw is started, the belt starts rotating around the wheels. The
material to be cut is brought into contact with this toothed edge. A
band saw is ideal in cases where the cutting line is irregular. This
tool is applicable for a variety of materials, such as wood, timber,
hardened plastic, or even metal. Both ferrous as well as non-ferrous
metals can be cut with this saw. The radius of curved cuts from a band
saw depends on the width of the band. Generally, narrow blades are used
for cutting tight curves, while broader blades are used for straighter
cuts. The band saw is a versatile tool that can be used for high
intensity tasks in sawmills, right from sawing large logs to small
desktop jobs like cutting and joining. The tool is used for resawing,
which involves cutting timber in the direction of the grain, to make
larger wood sections smaller. This saw is used by skilled workers such
as carpenters, masons, and plumbers, as well as non-professional home
users.
Features and working of a band saw
The movement of the toothed band in the band
saw is powered with a motor using approximately 4 to 8 amps, to offer a
no-load blade speed of around 200 to 600 feet per minute. This speed
can be controlled by the user depending on the target material and the
task to be performed. The speed of the saw as well as the density of
the material being cut can generate a certain amount of friction, which
can cause overheating and also shorten the life of the blade. Many band
saws, especially those used to cut metals, incorporate a water pump
assembly that emits a stream of water along the cutting portion of the
blade. This flowing water helps to cool the blade. Additionally, it
also prevents chips and other granules from getting stuck in the blade
teeth, and a wire brushwheel is provided to clear these entanglements.
The band saw blade widths range from around
1/8 to 1 inch. Different blades are used for different tasks. A regular
toothed blade having finer teeth enables smoother cuts. The skip
toothed blade has a 0 degree rake angle and is applicable for softer
wood. The hook toothed blade, with a 10 degree rake angle, is ideal for
harder wood and other more demanding sawing tasks. The finer the teeth
in a blade, smoother will be the cut, but the cutting speed will be
slower. Normally, a wider blade offers more stability, but may not
always be applicable for excessively meandering cuts. The presence of a
blade tightening lever eases the task of removing and replacing blades.
Dual ball bearing guides enhance the precision of the tool.
The body of the tool is designed for
durability and stability with the frame and base made of heavy gauge
steel. A swivel vice enables the saw to be used to make miter cuts,
which are slanting cuts in two pieces of wood that will later be joined
together at an angle.
Generally, band saws have three distinct
kinds of feed mechanisms; hydraulic feeding implies movement of the saw
using a hydraulic piston, gravity feeding uses the saw’s own weight to
let it fall against a shock absorber at the base, and a screw feeding
moves the saw by manipulation of a leadscrew. The fall mechanisms
incorporated, too, fall into three categories; single column saws move
over a column having a large diameter, dual column saws exhibit
enhanced accuracy and stability with a column on either side of the
work, while pivot saws are hinged and move in an arc over the
workpiece.
What to look for in a band saw
For added accuracy, some of the saws are
shipped with a work-lamp that illuminates the work-area. A miter gauge
helps the user make quick miter cuts using the band saw. Sometimes the
saw is partially coated in a rubber layer to protect it from impacts
and bumps, which are a common occurrence during usage. A saw which has
the motor above the blade, usually displays better balance. An
adjustable foot enhances the precision of the tool by providing a more
rigid seating.
Manufacturers intentionally try to make the
saw compact and lightweight, with ergonomic grips, to increase the
comfort Level of the user and reduce fatigue during prolonged use. A
lithium-ion battery provides longer runtime.
Some reputed manufacturers
of band saws include Delta, Dewalt, Jet, Makita, Milwaukee,
Porter-Cable, and Stout tools.
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