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Mechatronics Learning Studio

 

 

Hand to Mechanical Hand

 

Justin Leclair, Guillaume Archambault, and Daniel Cormier

Dept of Mechanical Engineering, University of Ottawa

 

 

 

 

 

Materials

-   Arduino Demilnuevo

-   Cotton strings

-   3 HS 785 Sail Winch Servos*

-   Breadboard

-   3 resistors

-   Connection wires

-   3 Fingers

o   All Round Galvazined trapping (3/4 in)

o   Rivets

o   Hexagonal nuts and bolts

o   3 long door springs

o   Pulley

o   Corner braces (6)

o   Screws

o   Wooden plank (base)

o   Tie wraps

o   Metal guides

 

 

1.      Attach a cotton string to the tip of one of the fingers and pass the string through the metal loops towards the motor’s pulley in line with it and repeat for every finger.

 

 

 2.      Put grease in every joints on the fingers

3.      Connect a 5V power source (Battery or USB-B plug from a computer) in the proper port on the Arduino board.

 

 

4.      There are 2 wires coming out of every sensor on the glove (green for thumb, black for index and white for middle finger).

 

 

a.       Attach one of these wires to the corresponding color lines on the breadboard.

b.      Attach the other wire in series with the resistor on the breadboard as shown. 

 

 

5.      Connect the motors (steps for every motor)

 

 

a.       Connect the red line of the motor to the power line on the breadboard

b.      Connect the black line to the ground line on the breadboard

c.       Connect the yellow line in digital 1 for the thumb, digital 2 for index and digital 3 for middle finger on the Arduino’s ports.

 

 

6.      Put the glove on.

7.      Calibrating the motors

a.       Put your hand flat (with palm toward the table). The motors should move a bit. They are going to their initial positions (position 0)

b.      With the help of someone else, attach the strings coming from the 3 fingers to the pulley of the motor (white section) with a sturdy knot.

c.       Adjust the length of the string in order to get a small tension in the initial position of the motors. Cut the excess string.

8.      Personal preferences

a.       Adjust the strength of the springs by changing the length of the tie wraps

 

The 3 fingers can now be used as a hand to grasp small objects.

 

 

Appendix - Motor’s specification