“Log Splitter”

“LOG SPLITTER”

PROJECT REFERENCE NO. : 37S0913

COLLEGE : SRINIVAS INSTITUTE OF TECHNOLOGY, MANGALORE BRANCH : MECHANICAL ENGINEERING GUIDE : SADASHIV LALASANGI STUDENTS : SANKESH RAFATH ABDUL RAZAK B E VACHAN RAO SACHIN KUMAR KEYWORDS: Firewood, Conical Screw, Manual Splitting, Hydraulic Splitting.

INTRODUCTION:

These last few years the forest resource is increasingly prized especially due to important needs in wood energy. Traditional crops are widely used, however an important resource such as stumps or difficult trunks (knotty, large diameter) are few or not valued. Splitting the wood is the way to value this unused resource. Especially as splitting wood, allows fast and natural wood drying. It also gives to firewood better quality and guarantees superior combustion.

Axe has been the one and only tool used to cut firewood since earlier times. It is a work which requires skill and strength. There are many firewood depots in the country where the wood is cut using axe. Even in this era of LPG cooking the demand for firewood has not come down. Firewood is not only used for cooking but also for boiling water. Gas/Electric Geysers are used in the urban areas but firewood is still extensively used in villages for boiling water. Splitting of firewood using axe is tedious job. After the advent of hand held chain saw, the process of cutting wood into smaller lengths has become easier and faster. But for lengthwise splitting of wood, chain saw cannot be used when the wood is for firewood. Cutting wood using chain saw makes the surface of wood smooth. Firewood surface should have sharp edges or splinters in order to catch fire easily. Hence if a machine has to be designed for log splitting, it should split log such that the effect is similar to that of splitting using axe.

In the present design, the aim is to speed up the process of splitting logs and reduce the effort and cost. A mild steel cone having v-thread on its surface (Taper thread) is used as a tool for splitting firewood. The tool is fit to a shaft driven by an electric motor. Log is fed such that longitudinal axis of wooden log is perpendicular to the axis of rotation of the tool. The speed of the motor is reduced by using the v-belt drive and torque is increased to suit the requirement. A three phase AC induction motor is used so that the direction of rotation can be reversed if the tool gets jammed in the wood. OBJECTIVES:

1. To split wooden logs for firewood purpose. 2. To split logs in such a way that it catches fire easily. 3. To reduce the effort required to split wooden logs 4. To replace the use of axe 5. To split logs faster 6. To split logs continuously 7. To avoid the use of skilled labour. 8. To split logs of varying sizes 9. To make the process simple 10. To split all kinds of logs- dry, wet, with knots etc.

METHODOLOGY:

BRIEF DESCRIPTION: In the present design, a cone shaped tool having a taper thread is driven by an electric motor. The motor speed is reduced by using a v belt drive and torque is increased. A three phase AC induction motor is used so that the direction can be reversed in case the tool gets jammed in the wood. The motor is fit on an adjustable platform to adjust the belt tension. A smaller pulley is fit to the motor shaft at the bottom. A parallel shaft supported by two pillow block bearings is driven by the motor below. For this, the parallel shaft has a larger pulley keyed to it at one end and the other end has the tool. Tool is fit to the shaft using two bolts diametrically across the tool shank. The table which extends in front of the tool supports the wooden log and also prevents the log from rotating along with the tool.

DIMENSIONS OF COMPONENTS

CONICAL TOOL

Fig 4.1-Dimensions of Conical Tool

MAIN FRAME STRUCTURE

Fig4.2- Dimensions of Main frame structure

FEED TABLE

Fig 4.3- Dimensions of Feed table

SHAFT

Fig 4.4- Dimensions of Shaft

PULLEYS

Fig 4.5- Dimensions of large pulley

Fig 4.6- Dimensions of small Pulley

MOTOR BASE

Fig 4.7- Dimensions of Motor Base

Tool Specification:

Tool no. 1

Taper thread

Metric –V

Pitch = 2.5mm

Cone angle = 300

Cone length = 120mm

Length of the shank = 20mm

Total length of the tool =140mm

Fig 6.1- Specification of tool no.1

Tool no. 2

Taper thread

Metric –V

Pitch = 5mm

Cone angle = 19.850

Cone length = 200mm

Length of the shank = 90mm

Total length of the tool = 290mm

The maximum diameter of the wooden log is limited to 1 foot in the current project. Based on this, the length of the cone was fixed to 200mm (about two third the diameter of the wooden log).

Fig 6.2- Specifications of tool no.2

Material Used

The tool is made of mild steel since it is economical and easily machinable.

Chemical composition and properties of Mild steel:

Carbon percentage = 0.05-0.25%

Young’s modulus = 210 GPa

Yield strength = 250 MPa Results and conclusion

The first tool of 2.5 mm pitch, full cone angle of 30 degree and 120 mm cone length was tested. It was directly fit to the motor shaft. The wooden log was fed against the tool in the transverse direction. But the tool got jammed in the wood. This was due to two possible reasons-

1. The cone angle is high. (30 degree)

2. The pitch was too small and as a consequence the friction increased.

To overcome these two problems, the following steps were taken.

1. Another tool of lower cone angle 19.85 degrees (based on length of the cone) was manufactured with a pitch of 5 mm.

2. The motor speed was reduced and the torque was increased. The calculation is shown in the calculation section of the report.

The log splitter is simple in design and is affordable. It is easy to use and effortless even for large scale log splitting. Mainly the log splitter is expected to cater the needs in the rural areas where firewood is extensively used. Log splitter will be a boon for firewood depots. Further, any place where there is regular usage of firewood, this machine is very useful.

Scope for Future Improvements

 The following improvements can be brought about in the log splitter.  The setup can be used for other purposes like coconut grating by changing the tool.  The setup can be made more compact by using a slow speed high torque motor by directly fitting the tool to the motor shaft.

 For continuous and heavy usage against hard wood, mild steel may wear out or the tool tip may get cut. In such a case, the tool can be made from steels such as EN8 (0.35% to 0.45% carbon) or EN9 (0.5% to 0.6% carbon)  This tool can also be fit to a wheel hub of an automobile and run using the engine drive.  Using a proper holding device, even coconut De- husking is a potential possibility.