The doors fixed on compartment will move to open and close the compartment using linkage mechanism. It will take the input from MIT app. i.e. after entering the correct password compartment will open.
MATERIAL LIST
1. Acrylic sheets
2. Links
3. Hinges
4. DC motors
5.Bluetooth module
6. Wheels
7. L-clamps
8. Nuts & bolts
9. Adapter
10. Breadboard
11. Wires
12. Arduino uno
13. Power jack
14. Relay
6.1 MOTOR SIZING
MOTORS FOR MOVING UNIT
Assume motor mass=300 gm
Mass of links=150 gm
Selected material is acrylic sheet
There is no load placed on sheet
Density of acrylic sheet=1.15 gm/cm^3
Density of foam sheet=0.35 gm/cm^3
Given dimensions are,
Length of sheet A=30 cm
Width of sheet A=30 cm
Thickness of the sheet A=0.4 cm
Length of sheet F=30 cm
Width of sheet F=15 cm
Thickness of the sheet F=0.4 cm
Volume of sheet A=30 * 30 * 0.5
v(A)=360cm^3
Mass of sheet A=Density*Volume
M(A)=0.414 kg
Volume of sheet F=30 * 15 *0.4
v(F)=180cm^3
Mass of sheet F=Density*Volume
M(F)=0.063 kg
There are 5 acrylic sheets of same dimensions
There are 2 foam sheets of same dimensions
Total load=2 * Motor mass+4 * M(A)+2 * M(F)+Mass of links
L=0.600+2.07+0.126+0.150
L=2.946 kg
Force=mg*u
F=2.946*0.25
F=0.7365 kg
Torque=Force*Radius
T=0.7356*4
T=2.964 kg-cm
Torque * FOS=2.964*1.5=4.419 kg-cm
We are using two motors
Torque on one motor=2.2095
We can choose 2 motor of 60 rpm each can sustain torque up to 3.6 kg-cm
MOTOR FOR LINKAGE MECHANISM
Assume motor mass=300 gm
Mass of links=150 gm
Selected material is acrylic sheet
Given dimensions are,
Length of sheet F=30 cm
Width of sheet F=15 cm
Thickness of the sheet F=0.4 cm
Volume of sheet F=30150.4
v(F)=180cm^3
Mass of sheet F=Density*Volume
M(F)=0.063 kg
There are 2 foam sheets of same dimensions
Total load=Motor mass+2 * M(F)+Mass of links
L=0.300+0.126+0.150
L=0.576 kg
Force=mg*u
F=0.576*0.25
F=0.144 kg
Torque=Force*Radius
T=0.144 * 12.5
T=1.8 kg-cm
Torque * FOS=1.8 * 1.5=2.57 kg-cm
We can choose 1 motor of 60 rpm WHICH can sustain torque up to 3.6 kg-cm
Motor(DC)
Torque(kg-cm)
Speed(rpm)
Motor 1
2.2095
60
Motor 2
2.2095
60
Motor 3
2.57
60
6.2 ADAPTER SELECTION
For DC motor
Operating voltage=12V
Current required=300 mA
Multiplying with factor of safety
Total current is
0.300 * 1.2=0.36 A
For 3 DC motors
Total current=3*0.36=1.08A
12V and 1.5 A adapter can be choose to operate a DC motor
For Arduino
Operating voltage=9V
current required=20mA
No. of pins to be used=8
Total current is
0.20 * 8 * 1.2=1.92 mA
9V and 2A adapter can be choose to operate an Arduino