Picture of Mechanical Hand
Students will make a simple mechanical hand with one articulating part. Once complete, students can test the ability of their hand by trying to pick up as many straws as possible. Extra class time (and there should be plenty!) can be devoted to further testing and redesigning to make the best mechanical hand possible!

Lesson Plan:

Grade range: 3-5
Prep: 2/5
Setup: 2/5
Cleanup: 1/5

Prep: Cut many 1/2 sticks
Setup: Set up glue guns

This project will require two 1-hour classes.

Start-of-class lecture (day 1)
  • Demonstrate your mechanical hand and the design challenge
  • Explain how it is operated and how it grasps
  • Show step-by-step how to make only the hand (steps 2-3)
Start-of-class lecture (day 2)
  • Show step-by-step how to finish the mechanical hand
  • Remind students of the design challenge and encourage them to try new ideas
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Step 1: Materials

For this design, you will need:
(and extra for redesigning)

15 Craft sticks
Craft cubes
Round cube beads
Part of 1 Straw
2 Skewers
2 Rubberbands
Hot glue

And a box of straws for the challenge!

Step 2: Build the hinge

Picture of Build the hinge
Cut two 1/2-inch pieces of straw. Wrap tape around the end of a skewer and thread the round cube beads and the straw pieces onto it as shown. Wrap tape around the other side and cut off the excess. 

The straw pieces act as spacers to prevent the fingers from colliding.

Step 3: Make the fingers

Picture of Make the fingers
Create the center finger as shown in the picture. The half-sticks are glued onto the side of the cube at a 45-degree angle.

The two other fingers are built similarly on either side of the center finger. Make sure that the half-sticks on the outside fingers are glued on at an angle that is inverse to the center finger.

On the 'back' of the hand, glue a half-stick to the two outside fingers. These two fingers will be actuated at the same time.
mohesh1 month ago

extremely awesome

TTSS1 month ago

Simply Wonderful.

That's awesome

Awesome! This would work great for a puppet hand :D thanks for sharing!

rimar20003 months ago

Good work! Maybe you could add a video.

audreyobscura3 months ago

So great!! Thanks for posting.


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