Mechanical Hand

Project Snapshot

The mechanical hand allows the user to single-handedly extend their reach!

Build the grabbing mechanism, and then customize the grabber's grip so it can pick up a variety of everyday things.

Click to expand

Tools and Materials

The Engineering Creation Kit has everything you need for this project and many more from STEM Inventions, or get the supplies in bulk:

• Hot glue gun

• Glue sticks

• Masking tape

• Craft sticks

• 1/2" craft cubes

• Cubes with holes

• 4" cable ties

• Straws

• 1/8" dowels

• ​Rubber bands

Tips and Troubleshooting

If the hand doesn't close when the trigger is pulled, then...

• Move the trigger farther from the handle.

• Redesign the angle of the "fingertips" so they're steeper. A hand with shallowly-angled fingers is harder to completely close.

If the hand doesn't open up automatically, then...

• Make sure the rubber bands are pulling the hand into an open position when the trigger isn't being pulled.

• Make sure there is nothing interfering with the mechanism, such as: loose bits of hot glue, the cable tie tied too tight, or excessive friction at the hinge.

If the trigger is hard to use with one hand, then...

• Review the video. Notice how the thumb is gripping the top of the thumb rest.

• Move the trigger closer to the handle to make it easier to grasp and pull, especially for small hands.