Building a Robotic Hand
This project is how to make a simple robotic hand out of easy assessable items that are usually cheep. most of these item can be found around the house or at a local dollar store and you can work with a group or just by yourself.
Supplies
Materials:
Dollarama
· Rubber bands
· Marker (sharpie)
· knife (or something else to cut in)
· Pliers
· Paper clips
· Fishing wire
· Sanding blocks
· Sewing needle
Michael’s
· Foam
Electronic
· Motors (servos)
· Arduino nano
· wire(really small ones)
Optional
· Something to cover your work space
Tracing & Cutting
first find someone to be you model, it can be anyone including yourself. next measure the length and width of your palm half of your forearm and each finger. draw out each on foam as rectangles and squares, keeping the palm and forearm connected. label each piece. After following the guidelines (don't forget to keep the forearm and palm together. you've drawn take out your Exacto knife and cut out each shape (It doesn't have to be perfect). Next take the rectangle fingers and trace out the area you model takes up. Finally cut off pieces slowly until you have a cylinder like shape
Sanding
*For this step you may want some sort of cover as not to make too much of a mess*
once the shapes are ready, start sanding them down into a more round shape. For the arm you want to lightly go over both flat sides so they wont crack in the future. on the fingers you want to sand down one end to a more round tip, making it look more like a finger. be careful not to sand down any part to much.
Cutting 2#
now take each finger an mark the joints according to your models hand. each finger will have two joints while the thumb will have one joint. once each joint is cut, cut a piece off at a 45* angle so the joint will be able to bend. each piece of the finger will have one 45* angle cut except the middle one, that one will have two one the top and bottom. don't forget to mark each one so you know which one is which.
Threading
take your sewing needle and thread your fishing wire through it (don't cut the wire), pull the thread a finger length to hold. push the needle through the top to bottom of each piece in the center, then at an angle thread the fingers so they go into the arm (upper palm). *do not thread it all the way through the arm, you want the needle out at the upper palm* Now pull the wire through until there is some extra wire from the end of the arm. cut the wire with an extra cm or three and double not at the finger. repeat for each finger.
Connecting
take the pliers and paper clips cutting of 4 pieces, then bend each piece until they're a "U" shape. choose four points (that line up down the arm) an take the wire lining it up. push the paper clip pieces in until there is a little wiggle space for the wire. repeat for each finger's wire.
cut rubber bands unto 6 small pieces (4 for the thumb) and line up each finger piece. hot glue the rubber bands to the back of each joint and from the finger to the back of the palm. be careful not to glue the wire.
Servos & Code
finally adding the motor, you can either leave it hanging or cut a hole in the arm and attach put it in there. my group decided to just leave it hanging.
take a motor and thread the extra wire through it. double not the wire and check to make sure it can still move. next wire the motor to the Arduino following the diagram above. use the codes above as a base reference for your code and make sure the code know each finger is separate. to make the robotic hand pinch set the motor to 90* for the pointer and thumb.
and there you have it, an robot hand