Motor sizing

1)Volume of Shaft(Long) =27227.136 mm3

2)Volume of Gear(3.5 cm)=7969.484 mm3

3)Volume of Gear(6 cm)=21021.274 mm3

*Total Volume=89256.234 mm3 =89.256234 cm3

*Mass=Density * Volume =Density of metal * Volume = 7.854 * 89,256234 = 701.01182g/cm3

*Torque= Mass * pi * 0.6 * 1.5 = 701.01182 * 3.142 * 0.5 * 1.5 = 2126.323 g/cm3 = 2.126 kg/cm3

= The Torque is 2.12 kg/cm3, so we use 100 RPM DC Motor.

Battery sizing

Sl.no	Components	Quantities	Operating Volatage	Operating current of each component	Total current
1	DC geared motor	2	12V	300mA	300*2=600mA
2	Arduino mega 2560	1	5v	100mA	100*1=100mA
3	IR sensor	1	5V	30mA	30*1=30mA

We can know that factor of safety is 1.3