Robotic Hand Instructable

For the past little bit of thee school year, our groups have been working on a making a robotic hand, with the goal of making it do a pinching motion with its finger when a button is pushed. Each member of the group was given different jobs to focus on, but for the most part everyone helped each other do everything.

Tools used:

• styrofoam - Used to build the palm, wrist, and fingers.
• rubber bands - Put on the back of the fingers to create resistance.
• hot glue - To attach the rubber bands.
• pliers - To cut rubber bands, paper clips, and fishing wire.
• fishing wire - Threaded trough the fingers.
• sanding blocks - Used to smooth out the styrofoam.
• paper clips - To hold down the fishing wire.
• sharpie - To mark where to cut the styrofoam.
• exactoknife - To cut the styrofoam.

To start off the project, you have to create the hand.

Firstly, you have to choose someone's hand to use for a model/reference to go off of. Once you've done that, you can start measuring the fingers and palm and marking it down on the styrofoam so that you know where to cut.

After you've marked everything you need to cut on the syrofoam using the sharpie, then you have to carefully cut out each piece using the exactoknife.

Once each piece is cut out, you have to sand them down. Sand the fingers into a circular shape so that it's more like the shape of a real finger, and then start getting ready to cut each finger into three pieces so that they can bend.

To make the fingers able to bend, you have to use the sharpie to draw the lines where you should cut each piece of the fingers into 45 degree angles. once you've done that, just cut the fingers and this step is done.

Second, you have to attach all of the fingers to the palm.

To do that, you have to take the fishing wire and a needle and thread the wire through each piece of the finger. Make sure that each piece is in the right place, and then put the wire through the palm as well.

Once the finger is attached to the palm, cut up paper clips into three pieces each, and use them as staples to hold down the fishing wire onto the hand.

If you've done this step correctly, the finger should go into the bent position when you pull on the wire.

Repeat this for all fingers.

The next thing you need to do is glue the rubber bands onto the back of each finger.

To start this off, you need to cut a few rubber bands into small pieces that would fit onto the joints of each finger.

Next, you need to use the hot glue to actually stick the rubber bands on. This can be difficult because hot glue and rubber don't really stick to each other very well, but if you put the glue all the way across to each side of the rubber bands and onto the styrofoam, it should work.

Once you've done that for every finger, pull on each string to make sure that nothing comes off.

After that, you need to do the coding.

For this, you need the measurements and sizes for each piece of the finger, and then use that for the code.

(I didn't do the coding and I have no idea how its done so I'm sorry)

Finally, you attach the servos.

For this, you have to take the fishing wire and thread it through each hole in the servo and then tie a knot at the end.

Attach all servos onto the wrist of the hand in whatever places they fit into best, and make sure that the fingers still move when you've done that.

Make sure that when you move the servos the fingers actually bend into the pinching motion, and when you put the servos back in their normal place, the fingers go back to their normal positions.