Calculating the weight of the bot:

Volume of base = base * height * width = 150 * 150 * 12 = 270,000 mm^3 = 270 cm^3

Volume of stand = base * height * width = 50 * 20 * 150 = 150,000 mm^3 = 150 cm^3

Volume of fibre holder = 3.142 * r * r * h= 3.142 * 15 * 150 * 15 = 106.042 cm^3

Volume of holder = base * height * width = 50 * 150 * 12 = 90,000 mm^3 = 90 cm^3

Volume of nylon of rod = pi * radius * radius * height = 3.142 * 10 * 10 * 50 = 15,710 mm^3 = 15.710 cm^3

Volume of squeeze = base * height * width = 50 * 100 * 10 = 50,000 mm^3= 50 cm^3

Total weight of base, holder, stand = (density of foam board) * (volume of base + volume of stand + volume of holder) = 0.1 * ( 270 + 150 + 90) = 51gm

weight of nylon rod = (density of nylon) * (volume of nylon rod) = 1.16 * 15.710 = 18.22 gm

weight of squeeze = ( density of rubber) * ( volume of squeeze) = 1.522 * 50 = 76.1gm

Weight of fibre holder = (density of fibre) * ( volume of fibre holder) = 3.9 * 106.042 = 413.5638 gm

weight of nuts= 10 * 1.23 = 12.3 gm

weight of bolts = 10 * 1.23 = 12.3 gm

weight of screw = 20 * 2 = 20gm

weight L clamp = 40 * 4 = 160gm

Total weight of bot = Total weight of base, holder, stand + Total weight of nylon rod + Total weight of squeeze+ weight of nuts+ weight of bolts +weight of screw+ weight of fibre holder.

Total weight of bot = 51+18.22+76.1+413.5638+12.3+12.3+20+160 = 763.4838 gm = 0.763 Kg

Motor Sizing

Our bot is around 0.763kg (W).

Wiper is of rubber and glass' co-efficient of friction (mu) is around 0.5 to 0.6.

Therefore F=(mu)*W.

F=0.6*0.763=> 0.4578 N

Torque=F*D/2

T=0.4578*1.4

T= 0.64092 Kg-cm.

therefore total torque = 0.64092 Kg-cm.

we are using 1 motors for wiping so divide the torque by 1.

so 0.64092/1=0.64092 Kg-cm.

Therefore we need 0.64092 Kg cm motor which is equivalent to 150 rpm motor of 12 v.

Battery sizing

component	Maximum current	operating voltage
1 DC motor	330mA	12v
1 led	20mA	3v
1 Arduino UNO	100mA	5v
2 Flex sensor	200mA	5v

FOS= 1.2

After multiplying FOS we get,

5V- 0.36A

12V - 0.78A

3V- 0.024A

so we need it for 2 hours

Therefore the battery capacities which we require will be,

12V - 1.56Ah

5V- 0.72Ah

3V- 0.048 Ah