Future Work

Following are commendations for the future work which will improve the performance of the fixture even further.

·         A custom designed motorized cross rail mechanism will reduce the weight of the fixture even further and will allow a more precise control over setting the depth of cut.

·         The comparative studies between conventional machining and ultrasonically assisted machining can be further extended to their effects on the tool wear.

Conclusion

The team has designed a fixture that is able to hold the force dynamometer and the ultrasonic transducer on the lathe machine replacing the conventional tool post. The team started their designing by selecting among various alternatives for thickness, material type and design. After performing computational analysis, the team decided to select the thickness of 20 mm, steel 1045 as material and a modified design for the fixture. The team also performed experiment using the designed fixtures for both conventional and ultrasonically assisted machining. The results of experimentation showed that ultrasonically assisted machining resulted in 30-40% drop in cutting forces for various cases.

Manufacturing

The following section presents the information relating the various phases of manufacturing of the fixture.

Purchase of raw material:

The team select steel 1045 as material, the brand name of steel 1045 is (C 45). The team bought steel 1045 as plate (100cm*100cm) from Ateyah Company.

Metal Cutting:

The team did cutting as Ox fuel Cutting (OFC).  The Ox fuel Cutting (OFC) is more and common and available in workshops.

Welding:

Joining process in which two (or more) parts are coalesced at their contacting surfaces by application of heat and/or pressure. The team did the arc welding as type of welding.

Grinding:

The team did the grinding to remove the sharp edge and to be more safety to use, and get good surface finish.

Cleaning and painting:

The team did the painting to get better texture. The team try to select same colour of lathe machine in the lap to be good looking when the fixture fixed on machine.

Project Goals

The aim of the project was to design a fixture for mounting the force dynamometer and the ultrasonic transducer on the lathe machine in place of the standard tool post. The new design of the fixture will be able to eliminate the vibration occurring from machining process. The team will use the new fixture to conduct a set of experiments on different types of steel. In addition, the team will measure the forces during the machining process.

Abstract

Force dynamometers are used to measure the force during various industrial applications. The use of ultrasonic transducer during machining can reduce the cutting forces, improve surface finish and also increase tool life. A strategic project in Taibah University has a standard lathe machine, a force dynamometer and an ultrasonic transducer. The strategic project is looking into the benefits of using ultrasonically assisted turning in reducing the cutting forces and improving the surfaces finish. To do so, the project required mounting the ultrasonic transducer on a standard lathe in place of the standard tool post of a lathe machine. The aim of this project is to design a fixture for mounting the force dynamometer and the ultrasonic transducer on the lathe machine. The team used the designed setup to conduct a set of experiments on steel and measured the cutting forces during the machining process.

The Ultrasonic transducer

An ultrasonic transducer is a device that is capable of generating and receiving ultrasonic vibrations. An ultrasonic transducer is made up of an active element, a backing, and wearplate.

 The active element is a piezoelectric or single crystal material which converts electrical energy to ultrasonic energy. It can also receive ultrasonic energy and converts it to electrical energy. The electrical energy pulse is generated from an instrument such as a flaw detector.

The backing is most commonly a highly attentive and very dense material and is used to control the vibration of the transducer crystal by absorbing the energy that radiates from the back face of the piezoelectric element. When the acoustic impedance of the backing material matches that of the piezoelectric crystal, the result is a highly damped transducer with excellent resolution. By varying the backing material in order to vary the difference in impedance between the backing and the piezoelectric crystal, a transducer will suffer somewhat and resolution may be much higher in signal amplitude or sensitivity.

The main purpose of the wearplate is to protect the piezoelectric transducer element from the environment. Wearplates are selected to generally protect against wear and corrosion.

Ultrasonically assisted turning:

Ultrasonically assisted turning is a metal removal technique, in which the cutting edge of a tool vibrates at a regular frequency within an ultrasonic range. There are three independent principle directions, in which ultrasonic vibration can be imposed in a turning operation. These include the feed direction, cutting direction and the radial direction.

The application of ultrasonic vibration along the feed direction enables the cutting parameters used in manufacturing industry for most materials to be reached independently of the workpiece diameter.

The Fixture

A fixture is a work holding or support device used in the manufacturing industry. Fixtures are used to securely locate (position in a specific location or orientation) and support the work, ensuring that all parts produced using the fixture will maintain conformity and interchangeability.

What is the lathe machine

A lathe is a machine tool, which there a cylindrical material mounted to it and cutting tool. The lathe machine turns cylindrical material to be cut by cutting tool. The lathe machine is one of the most important operating machines because, it is used in the production of cylindrical parts, also used in the production of rotary surfaces such as Nails and columns, couplings, cylindrical and conical tools .

The machining process on a lathe machine is performed by removing the chip from work piece.  The work piece is rotated about an axis of cutting tool, then the cutting tool is moved in the vertical direction and the right-and-left direction by operating various handles, so by rotating the work piece and moving the cutting tool, the work piece will take the desired shape. The cutting tool tends to be perpendicular to the axis of rotation of work piece.

Introduction

Standard lathe machine uses tool post for holding cutting tools but in case of the project allocated to the team, the tool post is going to be replaced with an ultrasonic transducer and a force dynamometer. A standard tool post cannot hold the ultrasonic transducer and a force dynamometer. The team designed a special fixture for holding ultrasonic transducer and a force dynamometer.

Tool post: is device which holds the cutting tool on a lathe and some other machine tools.