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DEVELOPMENT OF TOYS FOR TEACHING AND LEARNING OF MECHANICAL ENGINEERING Pranjol Paul   Scientific Officer (Gr II), Department of Mechanical Engineering, Indian Institute of Technology Guwahati , Guwahati-781039,  [email protected] 

Uday Shanker Dixit   Professor, Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati-781039,   [email protected] 

Abstract In this work, design and fabrication of some educational toys is discussed. The developed toys are useful in the teaching and learning of some concepts of mechanical engineering courses. The toys have been classified into three groups: (i) toys for teaching the basic principle, (ii) toys for describing a machine or mechanism and (iii) toys as experimental setup. In each group, a number of toys were developed. The response of the students indicated the potential of toys in enhancing the teaching performance. Some suggestions have been provided for incorporating the toys in mechanical engineering education.

Keywords: Educational Toys, Education Technology 1. Introduction The importance of laboratory classes in mechanical engineering education is well-recognized. Laboratory experiments help in the understanding of theoretical concepts and also teach the ways of applying theoretical knowledge to practice. However, imparting laboratory education is in no way less challenging than classroom teaching. First of all, placing laboratory courses at appropriate location in a course structure needs careful consideration. There is a difference of opinion regarding whether the theory course should precede the corresponding laboratory course or succeed it. Many educators prefer to teach theory and laboratory classes concurrently, but this system is difficult to implement in a large sized class. Often the students are divided into a number of groups in a big class and not all the groups can carry out their experiments in coherence with the theory class. The second major difficulty with regard to a laboratory course is the resource constraint. Colleges can have only a limited number of high-value experimental setups. With the increased batch size of engineering students, this problem has increased. Toys can act as a bridge between the theory and practical word without requiring much of resources. There are a number of advantages associated with the educational toys. With toys, learning becomes more enjoyable. They are inexpensive and can explain complicated phenomenon. A number of educators have used toys in engineering education. A brief review is presented here. Mikic and Grasso (2002) described a TOYtech project assigned to first year engineering students at Smith College which happens to be the largest women’s college in USA. A project TOYtech (Teaching Our Youth Technology) was initiated at Smith College as a part of first year course entitled “Designing the Future”. In this project, students were assigned to design and fabricate the toys that could be

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appreciated equally by all genres of pupils and could help them to grasp the elementary knowledge of science and technology through observation and introspection. A secondary aim of the project was to inculcate the public perception of engineering as a profession in service of humanity. Eventually, the students undertaking the project enjoyed the work and provided good feedback. The proper media coverage and interaction with a number of persons from the society helped in creating a positive awareness about the engineering profession. Innovators observed that educational toys have a tremendous impact on the development of spatial reasoning, critical thinking and problem solving skills, as well as increasing the child’s comfort levels with science and technology in general. Billard (2003) described an educational toy called Robota. Robota is a minihumanoid doll-shaped robot that is used in an introductory robotics class at the undergraduate level. The class offers an introduction to different tools necessary for building human-robot social interaction. Robota is 45 cm high with motors to drive legs, arms and head. The author has emphasized the use of Robota to cure children with autism. Sirinterlikci and Mativo (2005) mention that animatronics and other toy and entertainment technologies are part of very large industries, but have been generally neglected by engineering programs. The authors described one course launched by them in animation toy and entertainment design. Valente (2004) designed a course that is based on computational cards. Playing cards are used as computational elements. Computing machines can be defined, built and animated in a concrete way by disposing cards and moving objectified symbols, on top of them, following formal rules. Welch et al. (2000) explored the importance of sketching for novice designers. As a part of study, designs of various toys were undertaken. Some of the toys were a self assembly marble maze, a tower marble maze and a variant of base and cup game. In India, Department of Science and Technology (DST) has taken initiatives for the development of toy industry from time to time. A series of six regional workshop for teachers, craftsmen and designers for developing basic ideas and guidelines for creating hands on activities and toys to understand scientific principles was organized by Manthon Education Society, Ahmedabad. The programme was aimed at compiling, collecting and documenting information about existing traditional toys through which scientific principles can be explained. DST had also established gift and toy industry among priority sectors in Small Enterprise Technology Upgrading Programme (SETUP). Professor Amitabha Mukherjee of Computer Science and Engineering Department at IIT Kanpur is making use of robotics in education. He has launched a program called BRICS (Build Robots, Create Science) for schools. The missing “I” in the acronym stands for innovation. It is clear from this review that there have been sparse attempts to use toys in education. However, no work is visible where a significant number of educational toys have been used in a traditional course of mechanical engineering in teach and demonstrate mode. Many a times, complicated toys were used requiring much time for their fabrication. Moreover, no study is available in the literature that shows the clear cut mapping between theory portion and corresponding educational toy. The present paper describes a project for the development of educational toys for teaching different topics of mechanical engineering. The toys were fabricated by summer trainees, B. Tech. and M. Tech. students with the support of the technical staff of the department. The paper shares the experiences gained during the project and suggests some guidelines for introducing the design and fabrication of toys in undergraduate engineering course structure.

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2. Description of some educational toys At Indian Institute of Technology Guwahati, a number of summer trainees, B. Tech. students and M. Tech. students fabricated the educational toys. These students were assisted by the technical staff of the department in the supervision of the second author. The fabricated toys are of simple design. According to their purpose, the fabricated toys can be classified into three groups: (i) toys for teaching the basic principle, (ii) toys for describing a machine or mechanism and (iii) toys as experimental setup. This classification is not crisp as many toys may belong to more than one group with varying degrees of conformity. In this section, some sample toys of each group are described.

2.1 Toys for teaching basic principles Toys can effectively teach the basic principles of the science and technology. While learning the concepts using toys, the emphasis should be on a qualitative understanding rather than a quantitative one. In this subsection, two such toys are described. The design of these toys evolved with the effort of a number of students. The final form was provided by B.Tech. students Naresh Nallamala and Suman Kumar (2009).

2.1.1 Cantilever beam for learning the basics of vibration Figure 1 shows simple gadget in which the length of the cantilever beam can be adjusted. The beam can be freely vibrated and its frequency can be observed. The frequency increases with the reduction of the length of the cantilever beam. This can be seen with naked eyes; however, a digital clock (or clock in the mobile phone of the teenager) can measure the frequency. Thus, the correlation between stiffness and frequency can be demonstrated. The audible range of frequency is 20–20000 Hz. Hence, in a particular range of the beam length, vibrations will produce sounds of different pitches. This fact can also be demonstrated. The toy can also be used for studying the deflection of a cantilever beam.

Fig.1: Cantilever beam of adjustable length

2.1.2 Siphon toy Figure 2 (a) shows a toy model of a siphon which has widespread applications. The working principle of siphon can be explained with the help of Bernoulli’s principle. The toy has been named “Thirsty Doll”. Outwardly, there is a doll in the container. When the water is poured in the container, the level of the water increases till it reaches the lips of the doll. As soon as the water touches the lips of the doll, it starts coming out from the bottom of the container and empties the container.

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The actual siphon is hidden by the doll, which covers it. Figure 2 (b) shows siphon with doll removed. It consists of a U-tube, whose one end is pierced through the bottom of the container. An adhesive is applied for proper sealing so that the water cannot leak from the interface of outer side of U-tube and hole at the bottom of the container. The other end of the U-tube is left freely in the container with a very small gap. When the water is poured in, its level in the container as well as the U-tube increases. Once the water level reaches the crest of the U-tube, it starts coming out of the U-tube and siphon action starts. The water continues to flow till the water level in the container falls down to the very small gap between the open end of the U-tube and the container bottom.

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Fig.2 : Siphon toy (a) complete toy showing a doll (b) siphon with doll removed

2.2 Toys for describing a machine or mechanism This section provides the examples of some toys describing a machine or a mechanism. The toys can be static or working models. These toys mainly aim at reproducing the existing design of the machines that are in use and no innovation is carried out. In fact, utmost care and attention are put to fabricate these toys as per the features of the actual machine.

2.2.1: Models for machine tools A number of models of machine tools such as lathe, milling and drilling machine tools have been fabricated. All the models have moving parts and depict almost all salient features of the machine tools. For example, in the model of drilling machines table can be rotated as well as vertically moved. The model of the lathe shows the movement of carriage, cross-slide and tool post. Dovetail type guide ways are clearly shown.

2.2.2: Quick-return mechanism As a hobby project, an M. Tech. student Jyoti Kumar Doley fabricated a model of quick return mechanism used in shaper. The model is made of wood and it is possible to adjust the length of the crank and rocker arm. The project helped the student to become familiar with the workshop facilities available in the institute.

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2.2.3: Mechanism-kit Figure 3 shows a mechanism kit. It comes with a number of links. The learner can prepare various mechanisms and trusses with the help of these links. Links were made of Perspex material.

Fig. 3: Mechanism kit

2.3 Toys as experimental setups Toys can act as a replacement for many expensive experimental setups. Even if an expensive setup is available, it may be advisable to provide each student a toy experiment setup, in which the student can carry out his experiment individually rather than in the group. Two such experiments are described here.

2.3.1 Measuring the coefficient of friction When an object is just about to slide on an inclined surface, the coefficient of friction between the surface and object is equal to the tangent of the slope of the inclined surface. Figure 4 shows a gadget in which the slope of the inclined surface can be adjusted. There is a rectangular slot in the inclined surface, in which a rectangular piece of a sample surface can be fitted. The object is put on the sample surface and the inclination of the surface is adjusted to find out the slope of impending motion.

Fig. 4: Device for measuring the coefficient of friction

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2.3.2 Orthog gonal and oblique cu utting Figure e 5 shows a set up for studying ortho ogonal and o oblique cutting. The he eight of the cutting c tool an nd its inclination can be ad djusted. It is possible p to machine so oft materials like wax in this toy. One e can observve the cutting g phenomeno on and m measure the chip c flow angle in oblique cutting. Thiss toy helps in n understandiing the diifference betw ween orthogo onal and oblique cutting.

Fig. 5: Experime ental setup fo or orthogona al and obliqu ue cutting

3. Feedback k and obse ervations The developed toyys were dem monstrated in short term courses c and in the ga athering of scchool level sttudents. The participants were w enthuse ed by the toyys. The to oys made teac ching more in nteresting. Design n and develo opment of to oys has also been a thrillling and edu ucative exxperience. Students S lea arnt the use e of solid modeling m pa ackages, workshop te echnology and material se election. The task of toy-d development was entruste ed to a co ouple of B. Tech. T projectss. The advanttage with thiss type of B. T Tech. project is that th he student ca an learn with their own pa aces. The pro oject is almosst open-ended d. One ca an design an nd fabricate a number of toys t and can incorporate electronics or other te echnologies in n mechanical toys. The fa abrication of toys can also o be carried out as asssignments in n a regular co ourse. There is a scope to o offer an ele ective course on toy de esigning, which can have 6 laboratory h hours per wee ek. By con nducting som me informal su urveys, the au uthors have assessed a thatt about 0% engineering students get poor or no exposure e to practical classes of science s 70 du uring pre-eng gineering stag ge. This is du ue to the lack of facilities in the schoo ols and te endency to give g more em mphasis to theory course es. In no en ngineering en ntrance exxamination, a practical test t is condu ucted. Thus, many stude ents get han nds on exxperience on nly after joinin ng an engine eering college e. Toys can be b the first le earning sttep towards practical p engin neering and sscience.

4 Conclusions 4. This paper describe es the develo opment of som me educational toys. Educcational to oys help in learning durin ng their development as well as afte er they have e been de eveloped. The toys describ bed here are not expensivve. The cost of o each toy wa as less th han Rs. 500/-. In mass pro oduction, the price p may be in double dig gits of rupees. Thus, it is possible to o increase the e use of such h toys in teacching and learrning of mech hanical ngineering. en

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References 1. Billard, A. (2003), Robota: clever toy and educational tool, Robotics and Autonomous System, Vol. 42, pp. 259–269. 2. Mikic, B. And Grasso, D. (2002), Socially relevant design: the TOYtech project at Smith College, Journal of Engineering Education, Vol. 91, pp. 319–326. 3. Nallamala, N. and Kumar, S. (2009), Design and Fabrication of Educational Toys and Models, B. Tech. Project Report, Department of Mechanical Engineering, IIT Guwahati. 4. Sirinterlikci, A. And Mativo, J.M. (2005), A novel approach in integrating product design into curriculum: toys and entertainment animation design, Journal of Manufacturing Systems, Vol. 24, pp. 196–202. 5. Valente, A. (2004), Exploring theoretical computer science using paper toys (for kids), proceedings of IEEE International Conference on Advanced Learning Technologies (ICALT’04), 30 August-1 September 2004, Joensou, Finland. 6. Welch M., Barlex, D. and Lim, H.S. (2000), Sketching: friend or foe to the novice designer, International Journal of Technology and Design Education, Vol. 10, pp.125-148.

Acknowledgements This work is the part of All India Council for Technical Education (AICTE) sponsored project AICTE: 8023/RID/BOIII/NCP (21) 2007-2008 entitled “To Establish an Institute of Excellence (IOE) for Advanced Studies, Training and Research in Mechanical Engineering”. The financial assistance provided by AICTE is gratefully acknowledged.

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