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International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),

ISSN 0976 – 6359(Online), Volume 6, Issue 4, April (2015), pp. 126-133© IAEME

126

DUSTER DETACHING MECHANISM FOR

AUTOMATED MOTORIZED WHITEBOARD

Puneet Mathur1, Bhushan Tukaram Chougule

2, Ravina Raghunath Nangare

3,

Dr. M. S. Rohokale4

1,2,3,4Department of Mechanical Engineering,

Sinhgad Institute of Technology, Lonavala, Maharashtra-410401, INDIA

ABSTRACT

Erasable slates, a cheap but durable substitute for costly paper and ink, had been in use for

centuries. Students could practice reading and writing on their slates anywhere but for larger maps

and writing, blackboards were invented. Like many of the best tools blackboard is a simple machine

but with the innovations in the technology whiteboards are invented for eliminating the diseases

caused by chalk powder used in blackboards. This paper focuses on the design and construction of

automated whiteboard with the mechanism of attaching and detaching the dusters. The system

consists of many small parts and mechanisms which are used efficiently for the working of the

board. Some of them are: - Flexible whiteboard surface material, dusters, plastic rollers, cam and

follower, four bar mechanism and motors. The working of this system is based on rotation of flexible

whiteboard sheet material around the rollers. Rollers are operated by means of motors. When power

is supplied motors start rotating. The whiteboard surface material is rotated through motors and

gets cleaned automatically by the dusters fixed on the backside of the board. In this commutation an

attempt has been made to modify the features of automated motorized whiteboard by introducing a

duster detaching mechanism. Due to this mechanism teacher can use the writings on the board as a

future reference.

Keywords: Automated, Motorized, Detaching, Flexible

1. INTRODUCTION

In early 1800 teachers wanted to offer geography lessons to their students that required larger

maps so they connected number of small slates into a single grand field. This thought of the teachers

INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND

TECHNOLOGY (IJMET)

ISSN 0976 – 6340 (Print)

ISSN 0976 – 6359 (Online)

Volume 6, Issue 4, April (2015), pp. 126-133

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127

gave the idea of inventing blackboard. Teachers now had a flexible and versatile visual aid. Students

no longer simply listened to the teacher; they had a reason to look up from their desk. With the

growing technology it was observed that allergies and other health risks are occurred due to chalk

boards which demanded the replacement of blackboards with whiteboards [1]. Whiteboards are

analogous to chalkboards allowing rapid marking and erasing of markings on their surface. As time

became an important factor for people innovations in the technology started growing up rapidly. A

lot of time was wasted for rubbing large size blackboards and whiteboards due to which many

innovations were done on whiteboard for proper utilization of time.

2. RELATED WORK

Due to growing need of technology for human comfort continuous researches are carried out

all across the globe. Along with the innovations in the type of whiteboards like rotating whiteboard,

sliding whiteboard etc. cleaning methods used for the board are also modified. Remote control

motorized cleaners are made in which the dusters are operated with the help of remote control [2].

This type of cleaner moves horizontally by means of motor mechanism and erase the board with

the help of dusters attached to it but there are some limitations in above design. The pressure is

to be applied on the moving dusters for proper rubbing of the board and user have to wait till the

cleaner comes to its initial position. These limitations have been overcome by the design of

automated motorized whiteboard in which instead of moving the dusters the whiteboard surface is

moved around the rollers [3]. So there is no need of providing the external pressure on the dusters as

they are already fixed at the rear side of the board with certain amount of pressure. To make the

system more easy to use remote controlled sensors are inbuilt into the system [4]. This mechanism is

used to increase the efficiency of the system as it cleans itself by rotation of whiteboard

surface and the dusters fixed at the rear side of the board by just placing the hand or any

object in front of the infrared sensors placed on the top of the board.

As per the survey for further modifications teachers suggested to introduce a system for using

the written surface as a future reference. This was only possible by detaching the dusters from the

whiteboard surface. To implement this technique criss cross or cam and follower mechanism can be

used. But in large size whiteboards more magnitude of force was required for operating criss cross

mechanism which was practically not possible. Therefore cam and follower mechanism is used to

detach the dusters from the whiteboard surface.

3. SYSTEM DESCRIPTION

The major parts used for construction of system are as follows.

3.1 Wooden block

The wooden block is used as a supporting base for flexible whiteboard sheet material at the

time of writing on it. It is made up of wood but hollow from inside so as to reduce the weight of the

system. It is of length 80cm, breadth 5cm and height of 50cm. The front and back side of the wooden

block is laminated with sun mica so that flexible whiteboard sheet can easily move on it. It acts as

strong base for the system because plastic rollers carrying DC gear motors are mounted on it.Sliding

wheels are also mounted on top and bottom side of the board as shown in figure.



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Figure 1: Sliding wheels installed on base

Figure 2: Wooden block

3.2 Cam and Followers

A cam is a rotating machine element which gives reciprocating or oscillating motion to

another element known as follower. The cam and follower have a point contact and constitute a

lower pair. The cam is usually rotated at a uniform speed by a shaft, but the follower motion is

predetermined and will be according to the shape of the cam. In this system tangential cam is used

with flat faced follower.Cam is mounted on shaft which is manually operated. The material used for

cam is mild steel.

Figure 3: Cam and follower assembly

3.3 Four Bar Mechanism

A four-bar linkage is the simplest movable closed chain linkage. It consists of four bodies,

called bars or links, connected in a loop by four joints. Generally, the joints are configured so the

links move in parallel planes, and the assembly is called a planar four-bar linkage.

Degree of freedom is the number of independent coordinates required to define the position of each

link in the mechanism.

According to Grublers criterion:

F = 3*(n-1) - 2*p1 – p2 where, n- No. of links

F = 3* (4-1) – 2*4 – 0 p1- No. of lower pairs

F = 9-8 = 1p2- No. of higher pair

Degree of freedom for the mechanism is 1.



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This concludes that, the mechanism will move in only one direction i.e. in the direction of

force applied. This force is applied manually on handle which is connected to center rod and

common link between two four bar mechanisms.

Figure 4: Four bar mechanism with handle

3.4 Duster holders

Duster holders are of “C” shape having height 65cm, width 10cm and thickness of 1.2cm.

They are made up of plywood because it is cheap and durable for use. Three duster holders are

joined through aluminum strip and angle bars by keeping equal distances between them. The sliding

tracks are mounted at top and bottom of each duster holder. Dusters are fixed on the inner side of the

duster holders. The assembly of duster holders is placed in such a position so that pressure can be

applied by the dusters on the sheet. It is a fixed unit and in this system wooden block along with

motors and wheels are moving inside the sliders.

Figure 5: Duster holders and sliders

3.5 Slider and wheels

The function of sliders and wheels is to provide smooth longitudinal forward and reverse

movement of wooden block with respect to duster holders for attaching and detaching operation.

Aluminum sliders and high density plastic wheels are used in this system so that they will easily

carry weight of the main base and provide very less amount of friction due to its semicircular mating

interfaces.



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Figure 6: Slider and wheel

3.6 Springs

The main function of spring in this system is to retain original attached position of board with

dusters. Helical compression springs made up of stainless steel are used and placed at equal distance

from four corners. When cam is operated by 900

with the help of handle, the board gets detached

from dusters and due to this stretching of springs occurs as shown in figure. When applied force on

handle is removed, the stretched spring compresses back to its original position and dusters get

attached to the board.

Springs of stainless steel having modulus of rigidity 11200 MPa are used.

Mean diameter of spring = D = 20 mm

Coil diameter of spring = d =1 mm

Spring index = D/d = 20 /1= 20

No. of turns in each spring = N=14

Deflection of spring = ɗ = 10 mm

Deflection of spring is given by,

ɗ = (8*F*C^3*N) / (G*d)

10 = (8*F*20^3*14) / (11200*1)

F = 0.125 N

For 4 springs, total force = 0.125 * 4 = 0.5 N

Figure 7: Spring

3.7 DC gear motors and AC to DC converter

The DC Gear Motor has a speed of 100 RPM and is operated within the range of 4V-12 V. It

requires stall current of 6.9A and gives stall torque of 42.51 kg cm. The shaft length of motor is 25-

30 mm and shaft diameter is 8 mm. The gear assembly used in the motor is of spur gear. For

functioning of DC gear motors 12 V, 3 ampere AC to DC converter is used.

3.8 Whiteboard surface and plastic rollers

The flexible whiteboard sheet material is used in this system which can be rotated easily

around the rollers and is easy to clean. Renrenxin material is used instead of plastic material because

it has longer life and more durability.



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The rotation of flexible whiteboard sheet requires two rollers so as to rotate the sheet easily

from front to the backside of the board. Rollers made up of PVC plastic having diameter of 5cm and

height 50cm are placed vertically on right and left side of the wooden block. Two motors are

attached to each roller and placed on corners of main base.

4. ANALYSIS OF DESIGN

4.1 Analysis of cam and center rod

The analysis of cam rod is done by using ANSYS 14.0 software. Different forces are applied

on a cam rod on which cam is welded including self-weight of cam. Force of 2.5 N is applied at each

cam position and rotational velocity of 1.5 rad/s is applied to handle and cam rods. Also moments are

applied at same positions according to rotational speed of handle. The maximum total deformation

occurred due to this forces is 1.8133e-4 m and value of equivalent stress is 1.0213e7 Pa which is

negligible.

Figure 8: Static structural analysis of cam

4.2 Analysis of system The different parts of the system are analyzed by using ANSYS 14.0 software. Various forces

are applied on the base and holder assembly including the moment which is applied on the shaft of

the motor and rollers. The results obtained are shown in figures and maximum total deformation

occurred due to forces is 5.697e-6mm which is very negligible. Hence design & Analysis is

successful and can be implemented practically.

Figure 9: Static structural analysis of system



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5. CONSTRUCTION AND WORKING

The system is constructed by assembling two units i.e. stationary and movable units. The

stationary unit consists of dusters and sliders which are fixed in the duster holders. Four bar

mechanism along with cams and handle are fixed at the backside of the duster holders.The movable

unit consists of wooden block which acts as main base for this unit. Two motors are fixed on the

upper and lower side of the rollers. Two rollers are placed on the left and right side of the wooden

block and are connected to the shaft of the motors by welding. Two flat face followers are fixed on

wooden block. The flexible whiteboard material is rolled around the wooden block and rollers.Four

helical compression springs are attached between stationary and movable unit.

Now, considering the system is in use and the teacher wants to rub the board. When the

teacher switch on the supply, current is passed to the motors and they start rotating. Due to the

rotation of the shaft the rollers connected to it also rotates which in turn rotates the sheet around it.

The sheet moves from the front to the back side of the board and get rubbed due to the friction

between the sheet and the dusters. Meanwhile the sheet which is initially at the back side of the

board comes in the front for use.

When written text is required as a reference then by moving the handle, cam gets rotated by

900 and pushes the followers in forward direction along with movable unit. Due to this dusters get

detached from the board. When handle is rotated in reverse direction, the movable unit regains its

original attached position due to spring forces.

Figure 10: Front and Rear view of system

6. CONCLUSION

An automated motorized whiteboard with duster detaching mechanism has been successfully

designed and constructed. The system is tested and results obtained from the test carried out shows

that the system cleans the board as the supply is switched on. Moreover it can also be operated when

teacher wants to use the written text on the board as a reference purpose.



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REFERENCES

1. C.Betcher and M.Lee, The Interactive Whiteboard Revolution, (Camberwell Victoria, 3124,

Australia, by ACER Press, 2009).

2. T. Jacob, A Remote controlled motorized whiteboard cleaner, AU J.T. 15(4), Apr.2012,pp

273-280.

3. P. Mathur, B. Chougule and R. Nangare, Automated Motorized Whiteboard, IJEBEA, 2013,

vol. 1, issue 6, pp. 01-04.

4. B. Chougule, P. Mathur, Automated Motorized Sensing Whiteboard, IJARET, 2014, vol. 5,

issue 3, pp. 155-163.

5. Corp P and Hildebrandt P, Remote control for electronic whiteboard, U.S.Patent

US20040246236, Dec 16, 2004.

6. Bhushan Tukaram Chougule and Puneet Mathur, “Automated Motorized Sensing

Whiteboard” International Journal of Advanced Research in Engineering & Technology

(IJARET), Volume 5, Issue 3, 2014, pp. 155 - 163, ISSN Print: 0976-6480, ISSN Online:

0976-6499.

7. G Diwakar, M.V.H.Sathish Kumar and Dr..M R S Satyanarayana, “Detection of Gear Ratio

and Current Consumption using Motor Current Signature Analysis”, International Journal of

Mechanical Engineering & Technology (IJMET), Volume 3, Issue 2, 2012, pp. 643 - 652,

ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359.

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