DEVELOPMENT OF A MOTORISED HACKSAW

International Research Journal of Engineering and Technology (IRJET)

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DEVELOPMENT OF A MOTORISED HACKSAW David Atadious1, Onyekachi Tochukwu Dennar 2, Ibrahim Adebayo Alamutu3, Ikechukwu Patrick Onwuamaeze4 1,2,3,4Mechanical Engineering Department, Petroleum Training Institute, Effurun, Delta State, Nigeria.

---------------------------------------------------------------------***--------------------------------------------------------------------a type of Automatic Machine Tool whereas; the whole Abstract

purpose is cutting the materials (metal or non-metal) that consists less and even high thickness or diameter [4]. Power hacksaw have an arm section which is the reciprocating portion of the machine that cuts the material on a forward or backward stroke [6]. The tool is equipped with a clamping vice that has handles one can turn to tighten or loosen the grip on the work piece; it is a powerful part of the hacksaw that lock the object in position for cutting [3]. A Flywheel transmits the energy to the horizontal guide and also stores the energy according to the requirement [6].

This project introduces the development and assembly of an automated power hacksaw, engineered to cut metal materials into a range of sizes and lengths with precision. The central purpose is to streamline the metal cutting process, reducing the need for manual labour and saving valuable time, which ultimately leads to greater productivity. Through this series of connections, the rotary motion generated by the motor is converted into the reciprocating movement of the hacksaw blade which drives the cutting stroke of the hacksaw blade in the cutting operation. The Machine fabrication was executed according to the designed parameters developed and presented in the CAD model, yielding the following dimensions: 1167mm overall height, 1240mm overall length and 536mm overall width. The machine test was conducted at 502.32 rpm which produces an average cutting speed of 54(m/min) and Cutting force of 88.47N. In comparison to an already existing machine in the school workshop, the designed machine is proven to be approximately 23.8% more efficient on bases of energy consumption. All machine components were thoughtfully designed and constructed. The finished device was tested on various metals to assess its performance and reliability.

The manual used of hacksaw in a workshop is very stressful and time consuming, especially if the work piece to be cut is hard and with a large diameter. As a result, special tools with special precaution are needed to carry out this task; hence the idea behind this work.

2. DESIGN ANALYSES Several parts of the machine were designed which includes the electric motor, saw blade, power switch, saw frame, bottom plate and pulley connected with flat belt, brass bushes with shaft passing through it. The design details are shown in the diagrams of Fig. 1 – 5

1. INTRODUCTION

DESIGN CALCULATION

A hacksaw is a common tool for fitters, which can cut smaller round steel, angle steel, flat steel, plastic, wood and work piece [1]. A Hacksaw consists of basically two main elements: A frame with a handle and a blade [2]. Mainly there are two types of hacksaw frames; the fixed hacksaw frame and the adjustable hacksaw frame; the handles on the frames can be straight handle, pistol-type handle and tubular type handle [2][3]. A standard hacksaw blade length is 10 to 12 inches (250 to 300 mm) or can be as small as 6 inches (150 mm) [4].

Length of Belt Calculation

= Length of belt in mm, C = center distance between two pulleys, D1 = pitch diameter of the driving pulley, D2 = pitch diameter of the driven pulley =

Powered hacksaws generally use large blades in a variety of sizes, or small machines use the same hand blades for small operations [5]. The pitch of the teeth can be from 6 to 14 TPI (teeth per inch) for a hand blade and with nearly 6 TPI for a large power hacksaw blade [5].

Speed Reduction via Pulley

This project is tailored toward the design and construction of an auto electric power reciprocating hacksaw, to ease the manual labor (stress) and to save time toward the cutting operation in a workshop [6]. The Power Hacksaw Machine is

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where D1 = diameter of driving pulley (215mm), D2 = diameter of driven pulley 80mm), N1 = rpm of driving pulley (motor rpm = 1350rpm), N2 = rpm of driven pulley

where R = support forces at the fixed ends (N) Therefore Torque Calculation Power = 500W (specific by producer) Power= Torque T=

=

T (Driven) = 9.51 𝑁𝑚 Cutting Force

Bending Moment Analysis The bending moment which is the reaction induced in the structural frame when an external force (in this case, the weight of the auto-reciprocating machine) is applied to it is considered and treated as a beam fixed at both ends with uniformly distributed load.

Where F is the cutting force generated, r is the radius of the pulley

To determine bending moment, the bending moment diagram is established below: Cutting Speed Calculation Cutting speed refers to the speed at which the cutting tool or blade moves across the work piece during a machining or cutting operation (Ronan, 2024). It is typically measured in surface feet per minute (SFM) or meters per minute (m/min) and is a critical factor in determining the efficiency and quality of a cutting process (Ronan, 2024).

For one rotation of the driven pulley, the hacksaw moves two times linearly with only one effective cutting stroke.

Therefore, the cutting speed is calculated using the following formula:

Fig. 1: Bending Moment

𝐶𝑆 = Where M = moment at the fixed ends (Nm)

where 𝐶𝑆 is the Cutting speed in m/min

q = uniform load (N/m)

Strokes per Minute: The number of strokes made by the hacksaw machine per minute and is given as

L = length of beam There

(taking

measured weight of auto-reciprocating hack saw machine to be 500N)

𝑆𝑡𝑟𝑜𝑘𝑒 𝑙𝑒𝑛𝑔𝑡ℎ = 2 × 𝑑𝑟𝑖𝑣𝑒𝑛 𝑟𝑎𝑑i𝑢𝑠 = 𝐷𝑟𝑖𝑣𝑒𝑛 𝑝𝑢𝑙𝑙𝑒𝑦 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟 = 215𝑚𝑚

Support Reactions

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Therefore

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Plate 1: Pictorial View

Fig. 2: Pulley and Belt Details

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Fig. 3: Key Features

Fig. 4: Exploded View

Fig. 5: Main Base Details

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3. CONSTRUCTION DETAILS

xi.

The construction details that were followed in other to fabrication the electric power reciprocating hacksaw were as follow:

Components Construction Procedure

i. ii.

iii.

iv. v.

vi.

vii. viii.

ix.

x.

The operation of a manual hacksaw was first put into consideration, which produce a reciprocating (to and from) movement.

The hacksaw frame was then constructed from a mild steel plate with the shape of the English Alphabet C. The frame is 567mm, 250mm and 12mm thick.

A smooth straight shaft of 1100mm long was constructed with a spider (hollow) welded at one end of the rod, and two sleeve of 1½ inch by 100mm was welded on top of the frame.

An electric motor was then mounted on the base of the mild steel plate of 912mm, 355mm and 8mm thick.

A post was constructed, which was attach to a pulley that has been machine with a brass bush at it centered through a shaft that passes through the center of the hole of the pulley, thereby creating room for the pulley to be driven by the electric motor through an attachment of flat belt.

A hack link was constructed of 345mm, 40mm and 10mm thick, in which a brass bushes were fabricated at both ends. The hack link is attached to the pulley at one end and the hacksaw frame at the other end through the connection of a shaft, these connection help to create the reciprocating movement.

A clamping (vice) device was constructed from an angle bar of 10mm thick. This device helps to hold the work piece firmly during cutting operation.

The sitting position for the contraction was constructed, which serve as a circuit breaker and supplied current to the electric motor for operation to begin.

A sitting for an emergency switch was also constructed. This device helps to start the system and also put off the system after operation is terminated or completed.

An electric wire of 2.5 by 4mm was used to tap current from the power supply source. The electric motor is a three-phase electric motor that why the wire is 2.5 by 4mm. the working drawing.

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i. ii.

iii.

iv.

v.

vi.

|

A long bolt was attached to the long 110m shaft that helps to stop the emergency switch after the work piece has been cut off completely.

The hacksaw frame was constructed from a rectangular plate of 12mm of thickness.

The tensioned knob and blade pin were constructed with the used of 11 bolts and nuts. And a filing machine was used to smooth the rough surfaces that occur during cutting operation.

The clamping vice was constructed from an angle bar of 10mm thickness. Two isosceles triangle shapes was produced from it, which are 142mm by 80.3mm. One of the two pieces is connected to the base plate with the help of 14 bolts and nuts to hold it firmly to the base of the project work. The second piece passes through a slotted center line that allow movement from one end with the aid of a screw bolt when been tightening or loosing. A U shape pivot was drill on the center and welded with a 14bolt passing through the center hole and welded to the screw bolt. This enables the movement of the jaw.

The hack link was constructed from mild steel plate, producing 345mm by 40mm from 10mm thickness.

Two holes were drilled at both ends in which two brass bushes of 25mm of diameter were machine on the holes in other to create space for shaft to go through it.

The post bar was constructed from a mild steel plate of 358mm by 85mm.A hole was drill at the center from a distance of 170mm, and a shaft of 15mm of diameter is passed through the hole and welded firmly through the opposite surface The main base was constructed from a mild steel plate of 8mm thick. A rectangular line of 1098mm by 596mm was mark out and cutting operation was carryout. A distance of 119mm was mark out from both ends of the 1098mm plate. 2/3 of the mark out line was cut with filing machine in other to enable bending of the mild steel plate to make provision for the height of 119mm at both sides. A plate of 202mm by 197mm was also mark out from the front of the plate in other to have the shape in

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International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 12 Issue: 07 | Jul 2025

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3.1 RESULTS Table 1: Results Hacksaw Type

Test Specimen

Revolution per minute (rpm)

Cutting force

Cutting duration (secs)(min)

Cutting Speed (m/min)

Material

Dimensions (mm)

Designed Machine (500 W)

Mild steel

26mm Hollow Square Pipe (3mm Thick)

502.32

88.47N

32

54

Industrial Machine (3000 W)

Mild steel

26mm Hollow Square Pipe (3mm Thick)

215

192.1N

7

37.63

Manual Mild steel Handsawing

26mm Hollow Square Pipe (3mm Thick)

83

approximately 23.8% more efficient than the industrial machine.

From Table 1, we obtain the energy dissipated by both machines to establish a comparison in efficiency between the designed machine and the industrial machine at the school workshop. This can be deduce using the formula

4. CONCLUSION It is known that manually operated hacksaw can be replaced with an electric powered reciprocating hacksaw machine.

Electric power hacksaw machine gives high productivity in short time period, reduced labor force, and minimize stress which are very important in these days production process.

For Designed machine, Energy = 500 X 32 = 16,000 J For the industrial machine,

The electric power hacksaw machine can be made use of in small scale industries. The range of size of work-pieces that can be cut using electric hacksaw machine can be varied by changing the blade size.

Energy = 3000 X 7 = 21,000 J The energy efficiency of the designed machine compared to the already existing industrial machine is calculated as follows:

The machine is efficient and production cost is relatively low if they will be mass produced.

REFERENCES

𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 = 23.8%

[1]

Ronan, Ye. “Feed Rate and Cutting Manufacturing: Differences, Connection and Calculations.” 26 October, 2024.

3ERP. 21 June 2025 <https/www.3ERP.com>.

[2]

Siddhartha, N. S., Vishakaraj, S., Alphin, M. S., Vigneshwar, M., Vijayakumar, L. “Design of a Crank Operated Reciprocating Hacksaw.” Journal of Applied Mechanics and Materials 852 (2016): 564567.

[3]

Kumar, A.S., Manikanta, P., Lokeshwar, B., Kumar, S.S., Reddy, S.V.K., Rahul. M. “Design and Fabrication of Four Way Hacksaw.” International Research Journal of Modernization in Engineering Technology and Science 4.5 (2022): 4246 - 4253.

Therefore, the designed machine is approximately 23.8% more efficient than the existing industrial machine, based on energy consumption.

Table 1, emphasizes the important of cutting force in power hacksaw cutting operation. Even when the cutting speed of the designed machine was more than that of the industrial machine, the cutting duration of the industrial machine was less than the designed machine. This is due to the enormous cutting force of the industrial machine. However, from the deductions of the energy dissipated, the designed machine is

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[4]

Kohale, U., Adhao, S., Thakare, D., Panchawate, A., Dalvi, S. and Akarte, P. “Design and Fabrication of Motorized Hacksaw Machine.” International Journal for Research in Applied Science and Engineering Technology 10.5 (2022): 3697–3703.

[5]

Anon. “Types of Hacksaw Blades and Hacksaw Frames.” 26 June 2025. Engineering Learn. <https://engineeringlearn.com/types-of-hacksawblade-hacksaw-frame/>.

[6]

Nazar, M., Singh, K. K., Mahato, P. K., Kumar, R. Automatic Power Hacksaw Machine using Slider Crank Mechanism. Unpublished B. Tech. Project Repor. Phagwara - India: Department of Mechanical Engineering, Lovely Professional University, 2015.

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