9. Motor sizing and battery sizing - B-Division-2022-2023-Odd/Repo-04 GitHub Wiki
Materials used and their specifications:
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our model contains 12 clamps. weight of 12 clamps=120g
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our model contains 2 linges. weight of 2 linges=32g
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our model contains 36 screws with nuts and washers. Weight=15g Total mass mass=32+120+15=167g=0.167kg/cm
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our model contain foam board and acrylic sheet.
density of foam board:1g/cm^3
density of acrylic sheet:1.185g/cm^3
Motor sizing:
volume of arm: 15.242.540.6*2=46.45cm^3
volume of cuboid: =1651.6cm*3
volume of sphere: 2/3*pir^3 =16.74cm^3
We need two servo motors for the model, therefore motor sizing required for lifting the arms is :
volume of arm + volume of sphere = 46.45cm^3 + 16.74cm^3 = 63.19g/cm^3 = 0.063kg/cm^3
mass=rho*v
=63.19*1.185
=74.88g/cm
=0.074kg/cm
mass of a coin=6g=0.006kg
mass of 6 screws with nuts and washers=2.4g=0.0024kg
total mass=0.074+0.006+0.0024 =0.08kg/cm
F=m*r
F=0.08*15.24
F=1.21*1.5(safety factor)
F=1.81kg/cm
Therefore, we need SERVO MOTOR-TOWER PRO MG90S at 4.8V stall torque with operating voltage of 4.8-6.6V and stall current of 700mA.
Motor sizing required to eat the coin :
volume of cuboid/2=1651.6/2
=825.8g/cm^3
=0.825kg/cm^3
density of foam board:1g/cm^3=0.001kg/cm^3
mass=rho*v
=0.001*0.825
=0.00083kg/cm
Mass of 14 screws=5.83g=0.00583kg
Total mass=mass of cuboid+mass of 14 screws
=0.00083+0.00583
=0.0066kg/cm
Radius=20.32cm
F=m*r
=0.0066*20.32
=o.13*1.5(safety factor)
=0.19kg/cm
=1.8kg/cm
Therefore, we need SERVO MOTOR-TOWER PRO MG90S at 4.8V stall torque with operating voltage of 4.8-6.6V and stall current of 700mA.
Battery sizing:
COMPONENTS USED AND THEIR SPECIFICATIONS:
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Ultrasonic sensor:
Current requirement: 15mA
Voltage requirement: 5V
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16*2 character LCD display:
Current requirement: 1mA
Voltage requirement: 4.7-5.3V
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Arduino mega 2560:
Current requirement: 40mA
Voltage requirement: 7-12V
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2no's Servo motor-Tower pro MG90S:
Current requirement: 700mA*2=1400mA
Voltage requirement: 4.8-6.6V
Total current requirement: 15mA+1mA+40mA+1400mA=1456mA=1.456A
Therefore, we need one 5v adapter for the servo motors and the LCD display and the power for ultrasonic sensor and LED bulb is supplied by the ultrasonic sensor.