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10.1

Major VersionM

by Pete Prodoehl

Introduction

Make a paper octopus that retracts its tentacles.

Video Overview

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  1. Cut out a tentacle Fold it in half with the template markings on the outside Tip: You can save some time by folding the tentacle in half, then cutting the rounded top part
    • Cut out a tentacle

    • Fold it in half with the template markings on the outside

    • Tip: You can save some time by folding the tentacle in half, then cutting the rounded top part

  2. Use a sewing needle to make the holes in the marked locations Make sure to go through both layers of paper Make sure to go through both layers of paper
    • Use a sewing needle to make the holes in the marked locations

    • Make sure to go through both layers of paper

  3. Fold the tentacle in a zig-zag Unfold the tentacle, then refold it inside out so the template markings are on the inside You can also leave the template markings on the outside if that's your style!
    • Fold the tentacle in a zig-zag

    • Unfold the tentacle, then refold it inside out so the template markings are on the inside

    • You can also leave the template markings on the outside if that's your style!

    • Optional: add glue when you fold it in half to hold the two layers together (it's not necessary since it holds its shape pretty well without glue)

  4. Cut a piece of thread around 12" long Double or triple knot the end of the thread
    • Cut a piece of thread around 12" long

    • Double or triple knot the end of the thread

    • Thread the needle

  5. Use the holes you made in step 2 to sew the thread through the tentacle Make sure to start from the rounded end of the tentacle, and on the outside of the zig-zag fold Add a drop of glue (or tape) on the knot to make sure it doesn't pull through the paper
    • Use the holes you made in step 2 to sew the thread through the tentacle

    • Make sure to start from the rounded end of the tentacle, and on the outside of the zig-zag fold

    • Add a drop of glue (or tape) on the knot to make sure it doesn't pull through the paper

    • Double check that the knotted end is on the rounded side of the tentacle, and the extra thread is on the opposite side

  6. Repeat 7 more times until all 8 tentacles are finished
    • Repeat 7 more times until all 8 tentacles are finished

    • Set the legs aside for now to let the glue dry

    • Are you regretting making a robot with 8 legs? Just be glad it's not a centipede!

  7. Cut out the template for the body and top Fold the body following the markings on the template Fold the body following the markings on the template
    • Cut out the template for the body and top

    • Fold the body following the markings on the template

  8. Glue the body into an octagon shape (the two sections on either end should overlap on top of each other to form 8 sides) Glue the top on to the tabs Tip: I found it easiest to flip the body upside down while I was gluing the tabs in place
    • Glue the body into an octagon shape (the two sections on either end should overlap on top of each other to form 8 sides)

    • Glue the top on to the tabs

    • Tip: I found it easiest to flip the body upside down while I was gluing the tabs in place

  9. If you're feeling up to a challenge, you can also make the body using the origami method, which results in the twisty-top on this Octobot
    • If you're feeling up to a challenge, you can also make the body using the origami method, which results in the twisty-top on this Octobot

    • I used the instructions here to create an Origami Octagonal Box: Origami Octagonal Box

  10. Use the base stencil octagon to trace an octagon onto a piece of cardboard Cut the base octagon out of cardboard The base should be just small enough to fit inside the body (but not so small that there's loads of empty space around it)
    • Use the base stencil octagon to trace an octagon onto a piece of cardboard

    • Cut the base octagon out of cardboard

    • The base should be just small enough to fit inside the body (but not so small that there's loads of empty space around it)

  11. Glue a tentacle to the bottom of the cardboard base Only glue the last folded section of the tentacle (the one without a hole)
    • Glue a tentacle to the bottom of the cardboard base

    • Only glue the last folded section of the tentacle (the one without a hole)

    • Make sure the thread doesn't accidentally get glued to the cardboard

  12. Repeat for the other 7 tentacles Try to keep the threads from getting tangled Try to keep the threads from getting tangled
    • Repeat for the other 7 tentacles

    • Try to keep the threads from getting tangled

  13. Cut the servo holder template Fold the servo holder
    • Cut the servo holder template

    • Fold the servo holder

    • Glue it around the servo

    • You don't need to glue the paper to the servo—just wrap the servo holder around the servo, and glue it where the two parts overlap

  14. Glue the servo holder to the cardboard base of the Octobot Note that the servo itself isn't centered on the body—the servo's shaft is what should be approximately centered
    • Glue the servo holder to the cardboard base of the Octobot

    • Note that the servo itself isn't centered on the body—the servo's shaft is what should be approximately centered

  15. Cut a piece of straw about 3/4" long Use the needle to poke a hole through the straw at about halfway between the top and bottom Poke another hole (this one only needs to go through one wall) close to the top of the piece of straw
    • Cut a piece of straw about 3/4" long

    • Use the needle to poke a hole through the straw at about halfway between the top and bottom

    • Poke another hole (this one only needs to go through one wall) close to the top of the piece of straw

  16. Put the straw onto the servo shaft Since straws come in all different sizes, it may be too big. If that's the case, put a very small piece of tape around the servo shaft to increase its diameter
    • Put the straw onto the servo shaft

    • Since straws come in all different sizes, it may be too big. If that's the case, put a very small piece of tape around the servo shaft to increase its diameter

    • The straw should fit snugly on the shaft

  17. Sew one of the pieces of thread onto the straw First go through the middle holes, then up out the top
    • Sew one of the pieces of thread onto the straw

    • First go through the middle holes, then up out the top

  18. Repeat this 7 more times until all 8 pieces of thread are sewn into the straw It's best to do this one piece of thread at a time to avoid them getting tangled or twisted
    • Repeat this 7 more times until all 8 pieces of thread are sewn into the straw

    • It's best to do this one piece of thread at a time to avoid them getting tangled or twisted

    • Check that the length of the thread between the straw and the tentacles is roughly the same

    • You can check this by pulling the piece of straw up to check that the threads are all roughly the same tensions

  19. Push the straw to the servo shaft, making  sure it's snug (if it's loose, the shaft will just spin inside the straw without turning the straw itself) Make sure the tentacle are all fully extended, then tie a big knot where the threads exit from the straw Trim the extra thread
    • Push the straw to the servo shaft, making sure it's snug (if it's loose, the shaft will just spin inside the straw without turning the straw itself)

    • Make sure the tentacle are all fully extended, then tie a big knot where the threads exit from the straw

    • Trim the extra thread

  20. Connect the servo to the Bit Board at Servo Pin 1 Connect the servo to the Bit Board at Servo Pin 1
    • Connect the servo to the Bit Board at Servo Pin 1

  21. Upload the code from here: Octobot Code
    • Upload the code from here: Octobot Code

    • You'll note that the sound activation requires touching the logo at the same time. That's to avoid accidentally triggering it if you're in a noisy environment. You can change that by getting rid of the "logo is pressed" block

    • The sound trigger requires using the micro:bit v2. If you don't have the v2, there's loads of other ways you can trigger the Octobot, such as using the accelerometer to shake the micro:bit, or making it light-sensitive

    • It's easiest to test the mechanism while the servo is still exposed

    • Use the A and B buttons to try retracting and extending the tentacles

    • Tip: For the TentacleAction function, try playing around with the timing and speed to get different effects

    • Depending on how loose the threads are, you may need to pre-wind the threads around the axle by using the A button before triggering the TentacleAction function

  22. Put the body on The thread should slide into the thin cutouts in the body
    • Put the body on

    • The thread should slide into the thin cutouts in the body

    • The servo wire should go through the larger cutout

    • Optional: You can add a bit of glue to secure the body to the cardboard base (I didn't in case I wanted to access the inside)

  23. Give your Octobot a face!
    • Give your Octobot a face!

    • Touch the logo and shout "BOO!" to make Octobot retract its tentacles!

Finish Line

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Jasmine Florentine

Member since: 03/06/2021

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