This cardboard and string robotic hand flexes like a real hand and is controlled by your own movements.
Thank you to Ms. Moneca Conway of School District 60 - Peace River North for sharing this fantastic project with Skills Ready!
Watch a "Step by Step Tutorial" created by Ms. Conway using the video link under the project photos.
Thank you to Ms. Moneca Conway of School District 60 - Peace River North for sharing this fantastic project with Skills Ready!
Watch a "Step by Step Tutorial" created by Ms. Conway using the video link under the project photos.
Tools & Materials
Material List
- 4 x project stencils, numbered 1 through 4 (see images in procedure, or links to downloads in Youtube video description)
- 1 x Corrugated cardboard 12" x 24"
- 3 x Pipe Cleaners
- 5 x Straws (with bendy accordion necks)
- 8 x rubber bands
- 85" string
Tool list
- glue gun mat
- glue gun
- 3 x glue gun sticks
- cardboard cutting tools (utility knife or strong scissors)
- felt marker
- drill bit, roughly same size as straw
- masking tape
- strong ruler
Procedure
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Attach side A1 and side A2 of the arm stencil together using masking tape, and then tape side B1 and B2 of the arm support pieces together.
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Using the marker, trace around your stencils onto a piece of cardboard. You should have 4 pieces in total: the hand, the arm brace, the hand brace and the wrist brace.
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Cut out your cardboard pieces using strong scissors or a utility knife.
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Using your paper stencils for reference, use the marker to mark the black thumb string guide holes onto your cardboard arm.
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Drill out the marked black thumb string guide holes using the drill bit (just with your fingers, no need to put it in a drill).
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Using a strong ruler, crimp your cardboard fingers along the joint lines indicated on the paper stencil. This allows the fingers to become pliable.
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Cut 5 lengths of 17” string and tie knots on one end of each string. Use the overhand knot three times in the same spot for each string.
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Cut your straws into pieces: 17 x ½" pieces, 5 x 1-¼" pieces, and 2 x 3” pieces with the bendy accordion part in the middle.
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Using the glue gun, attach straw pieces to the cardboard as shown on stencil. ½" pieces go between finger joints, 1-¼" pieces go on the palm.
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Insert the 3” pieces with the bends through the thumb holes you drilled, and glue flat to the cardboard on the palm and back side.
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Thread the string through the thumb’s guidance straws, using the end of the string with NO knot. Glue the knot to the tip of the thumb (see the dot on the stencil as a reference point).
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Thread one string through the guidance straws for each finger, then glue the knots to the fingertips and snip off any excess string.
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Attach the last 1-¼" straw to the back of the wrist (in line with the thumb straw), and thread the thumb string through it.
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Thread the last 3” straw (with the bend) onto the thumb string, and insert it into the second thumb hole you drilled. Glue this straw down in line with the back of the wrist.
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Glue the rounded-edge robotic arm brace to the back of the wrist to stiffen the arm.
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Take the two remaining “I”-shaped cardboard pieces (hand and wrist braces) and bend them to make them pliable and easier to work with.
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Cut ½" slits in the cardboard arm tabs as shown on the stencil (these will hold the rubber bands that attach the braces to the arm).
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Use rubber bands to attach the hand and wrist braces to the robotic arm, sliding them through the slits from the last step.
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Make thumb and finger rings using pipe cleaners.
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Put your hand into the robotic cardboard arm. Using a marker, make dots on the cardboard where the first knuckles of each of your fingers sit.
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Next, tie your finger rings to the strings at the length marked by the dots made in the previous step. This will ensure that the rings sit comfortably in your first knuckles. Tie your thumb ring onto the thumb string at a length where it is easy to pull using the pad of your thumb.
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Test the finger rings and make sure they are all in a comfortable position where you have control over the fingers. Trim off any excess string from your knots.
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You may find that the knots glued to the fingertips begin to separate the layers of cardboard at the ends of each finger. To avoid this, use the glue gun to reinforce the corrugation and layers at the fingertips.
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Put your hand through the wrist and hand supports, fit the finger rings onto your fingers and thumb, and have fun!
Extension Challenges
- Decorate the back of your hand to make it look realistic, or glue aluminum paper to it to make it look metallic.
- Design a dexterity challenge where you and other people with their robotic arms have to complete a task using only the arms you've made.
- Make a robotic arm for your other hand.