Elastic-Powered Cardboard Mechanical Hand

This project is designed to showcase a simple yet effective design of a mechanical hand made from cardboard. Powered with elastic bands, this version of the project allows crafters to learn the basics of joint movements. Using simple materials found at home, this project encourages crafters to also recycle and make the most of what they already have! Feel free to tweak some parts of the template and start building yourself a mechanical hand!

This project only requires materials found around your household. Recycling would be a better option as well to reduce waste.

Materials:

1. 2 Cardboard Sheet
2. 1 Card Paper
3. 5, 15-inch String
4. 1, 12-inch Wooden Stick
5. 5 Elastic Band
6. Mechanical Hand Template (See attached file)

Tools:

1. Hot Glue Gun
2. Scissors
3. Heavy Duty Knife
4. Xacto Knife
5. Blade Refills (Optional)
6. Pen
7. Pencil
8. Eraser

Using the provided template, print the template. A useful tip in this step, is to make sure to resize the template on Google Docs or any platform that allows you to edit. This way, the mechanical hand will be able to fit your hand. For those unable to edit, check your print settings and adjust until you have template that fits.

Refer to the template labels and build each joint for each finger of the mechanical hand. For an easier time, build one finger at a time instead of assembling all the fingers at once. To achieve this, I recommend using a container separating each set of finger pieces from one another. Make sure you also do not mix up the joints per finger as well.

If you get confused, here is a simple breakdown of each term in this project:

1. Joint: Piece held on by the wooden stick.
2. Finger: Each moveable piece made up of joints.

Assembling each joint in one finger may be tricky, but please do not forget to refer to the last page of the template as it contains a pattern to follow for a more precise build.

Used the wooden sticks to attach the joint pieces together, forming one finger. Repeat for all five (5) fingers including the thumb.

Lastly, attach a string (Length for each string: 15 inches) to the very top of the "tip" joint, where the wooden stick is placed.

Using 2 pieces of small thin cardboard, attach the two ends of the elastic band as shown in the photo. Before gluing the elastic bands, be sure to glue pieces of card paper at the back of each joint in a finger to ensure a smooth surface for the elastic band to stretch on.

Lastly, add pieces of cardboard to secure the elastic bands from falling off each joint. Repeat for all 5 fingers.

For this step, I intentionally created no template for the palm piece as I wanted my fellow crafters to create their own design instead of just blindly following a single template. Once you figured a simple but effective design, trace and cut it out of cardboard.

Make sure the top and bottom of the palm piece has holes for the strings of the fingers to pass through.

Test the perfect spot for each finger to be placed for smooth movements. Then, attach each finger to the spot with a hole for the string to pass using hot glue.

Trace out your hand (based on what hand you used, right or left) on a piece of cardboard or card paper. We'll call this the "human piece" Create a rectangular piece to be connected to the palm piece, for the human piece to be placed inside of it. This will be our small control room.

Once you attached the human piece inside of the rectangular piece, glue each string as shown in the photo. Glue small rings made from card paper, that will be fit enough (not too narrow or wide) to allow your finger to grip on the fingers.

Final Modifications:

1. Add pieces of card paper to act as hinges for you to check the control room in case a string is broken. This allows for easier use of the mechanical hand, especially if the strings also get tangled.
2. Create a lock for the door piece (if you added hinges) to be able to hide the control room.

If you made it all the way to this section and created yourself a mechanical hand, then congratulations! Although this build can be tedious, it helps fellow crafters like me really see what we can do to innovate new ideas for the best of our community.

With that, I admit my mechanical hand had some flaws. So to prevent that from happening to yours too, here are a few notes I would leave:

1. Be mindful of the size of joints to avoid the fingers getting jammed of stuck to one another.
2. Keep the glue job clean and allow for it to cure properly, so the piece wont fall apart.
3. Plan out the finger placements on the palm wisely, maximize space to also avoid jamming.
4. Give generous space for the control room to operate, especially if your hand grasps a bigger area.

If you also take these notes in mind, I'm sure you will turn out to have a perfect mechanical hand! Don't forget to explore other kinds of designs, for example a mechanical hand that shoots darts as well. This is just one of the many awesome designs you can come up with!