# 7. MOTOR SIZING AND BATTERY SIZING - B-Division-2022-2023-Odd/Repo-12 GitHub Wiki

## MOTOR SIZING:

Our model contains 2 flip boards for folding the cloth, one with larger dimensions and another with smaller dimensions.

1. Dimensions for big flip board (Acrylic).

◦ Volume of 1 big flip board

``````Length = 30cm

Height = 0.2cm
``````

Volume = Length x Breadth x Height = 30cm15cm0.2cm = 90cm^3.

2. Mass.

Density of acrylic sheet= 1.18 g/cm^3. Mass= DensityVolume = 1.18 g/cm^390cm^3 = 106.2g = 0.1062kg.

3. Force Involved.

Force= Massgravity = 0.1062kg9.8 = 1.04076N.

4. Torque involved.

Torque= ForceRadius = 1.04076N0.075m = 0.078057Nm.

5. Maximum Torque.

Factor of safety= 1.5 Maximum Torque= Factor of safetyTorque = 1.50.078057Nm = 0.1170855Nm = (0.1170855Nm*100)/9.81 kg-cm = 1.1935 kg-cm. Here we require Towerpro SG90 servo motor.

## Battery sizing:

3 servo motor stall current= (650mA*3). 1 IR sensor= 20mA. 1 Buzzor= 20mA. 1 Arduino mega 2560= 40mA.

# Total current required= (650mA*3)+20mA+20mA+40mA

``````                  = 2030mA
= 2.03A.
``````

# Factor of safety= 1.2

Maximum current= f.o.sTotal current required = 1.22030mA = 2436mA. Therefore for our course project we are using 5V 2A Adaptors. Better to use separate adaptors for servo motors 5v, 2A.