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.
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Dimensions for big flip board (Acrylic).
◦ Volume of 1 big flip board
Length = 30cm Breadth = 15cm Height = 0.2cm
Volume = Length x Breadth x Height = 30cm15cm0.2cm = 90cm^3.
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Mass.
Density of acrylic sheet= 1.18 g/cm^3. Mass= DensityVolume = 1.18 g/cm^390cm^3 = 106.2g = 0.1062kg.
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Force Involved.
Force= Massgravity = 0.1062kg9.8 = 1.04076N.
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Torque involved.
Torque= ForceRadius = 1.04076N0.075m = 0.078057Nm.
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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.