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ABSTRACT
In this Pedal operated hacksaw machine which can be used for industrial applications and
Household needs in which no specific input energy or power is needed. This project consists of a
crank and slider mechanism. In the mechanism pedal is directly connected to the hacksaw through
crank and slider mechanism for the processing of cutting the wooden blocks, metal bars, pvc
materials. The objective of the modal is using the conventional mechanical process which plays a
vital role. The main aim is to reduce the human effort for machining various materials such as
wooden blocks, steel, PVC etc.
The power hacksaw machine, which runs on human power, works on the principle of the conversion of
rotational motion to oscillatory motion.
Importance of this project lies in the very fact that it is green project and helps us to reduce our
electricity need. Secondly, this cutter can be used and transferred to our working place easily.
Moreover, if we want we can generate electricity with our project by connecting it to dynamo, diode and battery
INTRODUCTION
Pedal power is the transfer of energy from a human source through the use of a foot pedal and
crank system. This technology is most commonly used for transportation and has been used to
propel bicycles for over a hundred years. Less commonly pedal power is used to power
agricultural and hand tools and even to generate electricity. Some applications include pedal
powered laptops, pedal powered grinders and pedal powered water wells. Some third world
development projects currently transform used bicycles into pedal powered tools for sustainable
development. This project concentrates on pedal powered hacksaw machining.
An individual can generate four times more power (1/4 HP) by pedaling than by hand-cranking. At
the rate of ¼ HP, continuous pedaling can be served for only short periods, approximately 10
minutes. However, pedaling at half this power (1/8 HP) can be sustained for close to 60 minutes
but power capability can depend upon age . As a consequence of the brainstorming exercise, it was
apparent that the primary function of pedal power one specific product was particularly useful: the
bicycle. Many devices can be run right away with mechanical energy.
A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials.
The cutting edge of a saw is either a serrated blade or an abrasive. A saw may be worked by hand,
or powered by steam, water, electric or other power. An abrasive saw uses an abrasive disc or
band for cutting, rather than a serrated blade.
COMPONENTS REQUIRED
I. Hack saw blade
II. Pedal arrangement
III. Stand setup parts
IV. Crank and slider mechanism
V. Hack saw assembly
VI. Metal slab
2.1) PEDAL POWER HACKSAW
The principle of pedal power hacksaw is to change circulatory motion or cycling motion into
translatory motion with the help of metal cutting rod. This is mainly used for cutting metals and
plastics. it is manually pedal operated system.
If we use dynamo then we can produce electricity which will be help to lighting the work piece
area when electricity is not available in mechanical workshop.
A hacksaw is a fine-tooth saw with a blade under tension in a frame, used for cutting materials
such as metal or plastics.
Hand-held hacksaw consist of a metal arch with a handle, usually a pistol grip, with pins for
attaching a narrow disposable blade.
A screw or other mechanism is used to used to put the thin blade under tension.
It is a fine tooth hand saw with a blade under tension. It is used to cut metals and PVC pipes. It
would be useful in many projects discussed on this site which used plastic pipes as materials.
Blades of hacksaw are measured in TPI (Tooth Per Inch). Different TPI is needed for different jobs of cutting.
There are three types of cutters available in the market:
1. Simple hacksaw which can be used for hand cutting things.
2. Small Electrically Hacksaw for personal uses.
3. Large Cutter Machines used for Industrial Purposes.
From the above three, first one will be used for our project
ARECIPROCATING POWER HACKSAW
Ituses a blade that moves back and forth across the work. The blade cuts on the backstroke. There
are several types of feeds available.
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Positive feed-produces an exact depth of cut on each stroke. The pressure on the blade varies with
the number of teeth in contact with the work.
Definite pressure feed-yields a pressure on the blade that is uniform regardless of the number of
teeth in contact with the work. The depth of the cut varies with the number of teeth contacting the
work. This condition prevails with gravity feed.
Feed can be adjusted to meet varying conditions. For best performance, the blade and feed must
be selected to permit high-speed cutting and heavy feed pressure with minimum blade bending
and breakage.
Standard reciprocating metal cutting saws are available in sizes from 6~ ~ 6~ (150 mm ~ 150
mm) to 24~ ~ 24~ (900 mm ~ 900 mm). The saws can be fitted with many accessories, including
quick-acting vises, power stock feed, power clamping of work, and automatic cycling of the
cutting operation. The latter moves the work out the required distance, clamps it, and makes the
cut automatically. The cycle is repeated upon completion of the cut.
High-speed cutting requires use of a coolant. Coolant reduces friction, increases blade life, and
prevents chip-clogged teeth. Cast iron and some brass alloys, unlike most materials, do not
require coolant.
2.1.1) Selecting A Power Hacksaw blade
Proper blade selection is important. Use the three-tooth ruleatleast three teeth must be in con-tact
with the work. Large sections and soft materialsrequire a coarse-tooth blade. Small or thin work and
hard materials require a fine-tooth blade.
For best cutting action, apply heavy feed pressure on hard materials and large work. Use light
feed pressure on soft materials and work with small cross sections.
Blades are made in two principal types: flexible-back and all-hard. The choice depends upon use.
i) Flexible-back blades -should be used where safety requirements demand a shatterproof blade.
These blades should also be used for cutting odd-shaped work if there is a possibility of the work
coming loose in the vise.
ii) All-hard blade -For a majority of cutting jobs, theall-hard bladeis best for straight, accurate
cutting under a variety of conditions.
Mounting a Power Hacksaw blade
The blade must be mounted to cut on the power (back) stroke. The blade must also lie perfectly
flat against the mounting plates. If long lifeand accurate cuts are to be achieved, the blade must be
properly tensioned
Many techniques have been developed for properly mounting and tensioning blades. Use a torque
wrench and consult the manufacturer’
s literature. If the information (proper torque for a given
blade on a given machine) is not available, the following methods can be used:
Tighten the blade until a low musical ring is heard when the blade is tapped lightly. A highpitched
tone indicates that the blade is too tight. A dull thud means the blade is too loose.
The shape of the blade pin hole can serve as an indicator of whether the blade is tensioned
properly. When proper tension is achieved, the pin holes will become slightly elongated,
The blade will become more firmly seated afterthe first few cuts and will stretch slightly. The blade
will require retensioning(retightening) before further cutting can be done.
2.1.3) Selecting a Band Saw Blade
Band saw blades are made with raker teeth or wavy teeth. Most manufacturers also make
variations of these sets. The rakersetis preferred for general use.
Tooth pattern determines the efficiency of a blade in various materials. The standard tooth
blade pattern is best suited for cutting most ferrous metals. A skip tooth blade pattern is
preferred for cutting aluminum, magnesium, copper, and soft brasses. The hooktooth blade
pattern also is recommended for most nonferrous metallic materials.
For best results, consult the blade manufacturer
’
s chart or manual for the proper blade
characteristics (set, pattern, and number of teeth per inch) for the particular material being cut.
Installing a Band Saw Blade
If the saw is to work at top efficiency, the blade must be installed carefully. Wear heavy leather
gloves to protect your hands when installing a band saw blade.
Blade guides should be adjusted to provide adequate support, Proper blade support is required to
cut true and square with the holding device.
Follow the manufacturer’
s instructions for adjusting blade tension. Improper blade tension ruins
blades and can cause premature failure of bearings in the drive and idler wheels.
Cutting problems encountered with the band saw are similar to those of the reciprocating hack
saw. Most problems are caused by poor machine condition. They can be kept to a minimum if a
maintenance program is followed on a regular basis.This typically includes checking wheel
alignment, guide alignment, feed pressure, and hydraulic systems.
PEDAL ARRANGEMENT
A pair of pedals is attached to the stand setup in which the power will be generated manually. A
typical Bicycle arrangement is used.
2.2.1) PEDAL
A bicycle pedal is the part of a bicycle that the rider pushes with their foot to propel the bicycle. It
provides the connection between the cyclist’s foot or shoe and the crank allowing the leg to turn
the bottom bracket spindle and propel the bicycle's wheels.
Pedals were initially attached to cranks connecting directly to the driven (usually front) wheel.
The safety bicycle, as it is known today, came into being when the pedals were attached to a crank
driving a sprocket that transmitted power to the driven wheel by means of a roller chain.
Pedals usually consist of a spindle that threads into the end of the crank and a body, on which the
foot rests or is attached, that is free to rotate on bearings with respect to the spindle.
STAND SETUP PARTS
Stands are introduced to immobilize the apparatus. Various components used are fixed to this
arrangement. The chassis of the bicycle is used as the stand setup parts .
The stand described here is designed to support most bicycles.
The stand assembly is divided into two parts: the rectangular base frame and two triangular
upright supports. Measure and cut the five pieces of 3/4" (20mm) angle specified for the base
frame. Mitre the corners at 45 degrees so they fit together tightly and form square corners.
2. Weld the rectangle together. Do not weld the center frame member to the rectangle yet.
3. Measure and cut as specified the 5 pieces for each upright support.
4. Carefully assemble the upright support pieces for welding, being sure to leave a 1/8"
(3.2mm) gap in the base of each support. This gap will mate with the center frame member of the
base frame, allowing the upright supports to slide to accommodate different rear axle widths. Note
that the two upright supports are not identical. They are mirror reflections of one another. Weld
each upright support assembly together into a secure structure.
5. Place the upright supports onto the base frame, and position the center frame member so that
it mates with the gap in the side supports. Mark its position, and weld it in place.
WORKING PRINCIPLE
It consists of the pedal arrangement which rotates the crank and through it slider consists of
oscillating mechanism. The power is transmitted to the crank and slider mechanism. This
mechanism is used to rotate the crank disc; the disc which is having an extended rod is connected
to the sliding portion of the hacksaw directly by means of a linkage. The hacksaw is passed
through the guide ways by means of maintaining the cutting axis. As the user operated the pedal,
the hack saw cuts the various materials automatically with less power. The dead weight is for
compressive force while the user operated the foot pedal.
DESIGN CONSIDERATIONS
When designing our attachment, the following considerations were taken into account
1. The device should be suitable for local manufacturing capabilities.
2. The attachment should employ low-cost materials and manufacturing methods.
3. It should be accessible and affordable by low-income groups, and should fulfill their basic need
for mechanical power
4. It should be simple to manufacture, operate, maintain and repair.
5. It should be as multi-purpose as possible, providing power for various agricultural implements
and for small machines used in rural industry.
6. It should employ locally available materials and skills. Standard steel pieces such as steel
plates, iron rods, angle iron, and flat stock that are locally available should be used. Standard
tools used in machine shop such as hack saw, files, punches, taps & dies; medium duty welder;
drill press; small lathe and milling machine should be adequate to fabricate the parts needed for
the dual-purpose bicycle.
7. It should make use of standard bicycle parts wherever possible.
The device should adapt easily to as many different bicycles as possible. No permanent
structural modification should be made to the bicycle.
9. Though the device should be easy to take off the bicycle, it is assumed that it would usually
remain attached to facilitate readiness and ease of transport from site to site. The device,
therefore, should not interfere with the bicycle's transportation mode.
10. The broad stand, which provides stability during power production mode, can be flipped
upward during the transport mode. This stand/carrier would be a permanent fixture of the dualpurpose
bicycle.
11. The power take-off mechanism should be as efficient as possible, and should develop
relatively high r.p.m. (close to 200) for versatility of application. We had seen designs for
devices that take power from the rear tire by means of a friction roller pressed against it, but we
had doubts about the efficiency of this arrangement. In order to improve efficiency we used
hard bearing surfaces such as roller chains, sprockets and ball bearings. We decided that the
most appropriate location for this power take-off mechanism would be at the front of the bike
near the fork tube (see photographs).
12. Care must be exercised to insure that the power take-off assembly is far enough forward so as
not to interfere with pedaling. Most standard adult bicycle frames have plenty of room for the
power take-off mechanism and pulley. Power is supplied to the shaft by means of a chain from
the bike's chain wheel (crank) to a ratcheted sprocket on the shaft. During the prime-mover
mode, the bike's regular chain is slipped off of the chain-wheel, and the specially sized chain to
the power take-off mechanism is slipped on.
13. The device should be able to transmit power to a variety of machines, and changing drive
ratios should be as simple as possible. We decided that a V-belt and pulley arrangement would
be most appropriate for this. Belts do not require the precise alignment that chains do. Belts can
even accommodate pulleys that are slightly skewed with respect to each other. Changing drive
ratios is as easy as changing pulleys. Also, belts are reasonably efficient.
14. The device should contain a ratcheting mechanism that would let the operator "coast "
periodically to rest and conserve energy. A free wheel from any bicycle can be easily adapted
for this purpose.
15. Excessive weight should be avoided, as durability is a prime consideration.
ADVANTAGES
I. Time saving as compared to simple hacksaw
II. Power saving as it is manually operated
III. Easy machinery used
IV. As it is pedal operated so good for health
V. Comfortable then ordinary hacksaw
VI. It is portable
VII. It could be used wherever metal cutting is done in small scales, including at construction
sites and furniture units, or to cut metal for window panes.
DISADVANTAGES
I. Its totally manually operated
II. Time consuming as compared to electrical power hacksaw
III. Without human effort its not operated
IV. Not fit for heavy production
CONCLUSION
Thus a low cost and simple design pedal operated hacksaw machine is fabricated. This machine
reduces the human effort and hence we don’t need two persons to cut the wooden logs. This
simple design of conventional design which can enhance day today household needs and daily
day to day purposes and it can be also used in for industrial applications during power shut down
scenarios. By using this method we can do any operation as per our requirement without the use
of electricity. so we can save the electrical power.