Robotic Paper Octopus (with Micro:bit)

Intro: Robotic Paper Octopus (with Micro:bit)

Make a grumpy paper octopus that retracts its tentacles in reaction to loud noises!

STEP 1: Making the Tentacles

• 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

STEP 2: Poke the Holes

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

STEP 3: Invert the Tentacle

• 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)

STEP 4: Cut and Knot the Thread

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

STEP 5: Sew the Tentacle

• 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

STEP 6: Make More Tentacles!

• 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!

STEP 7: Making the Body

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

STEP 8: Assemble the Top and Body

• 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

STEP 9: Alternative Body

• 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

STEP 10: Cut the Base

• 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)

STEP 11: Attach the Tentacles

• 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

STEP 12: Add the Other Tentacles

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

STEP 13: Make 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

STEP 14: Attach the Servo

• 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

STEP 15: Making the Axle

• 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

STEP 16: Check the Straw Size

• 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

STEP 17: Attach the Thread

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

STEP 18: Do It Again

• 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

STEP 19: Attach the Axle

• 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

STEP 20: Connect the Circuit

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

STEP 21: Upload the 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

STEP 22: Test It

• 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

STEP 23: Put the Body On

• 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)

STEP 24: Give It a Face

• Give your Octobot a face!
• Touch the logo and shout "BOO!" to make Octobot retract its tentacles!

Comments

[Ama_2460]

Hi, a quest how you stop the program?

[jrflorentine]

I'm not sure what you mean? If the problem is the tentacles are spending too long extending or retracting when there's a loud noise, you can adjust the durations by changing the number in the pause blocks to be shorter. Or if the issue is that it keeps getting accidentally triggered by a sound, you might need to adjust the threshold for the sound level to be higher. Let me know if that helps answer the question!

[mahmoud8373]

WOWOOWOWOW

[AnandM54]

Wow, awesome instructable... Brilliant idea and making!!!

[Techhlp]

That’s an ingenuous method to have all tentacles move at the same time. This will take some viewers back to their days building with metal Meccano no doubt. The use of string is not to be overlooked as a learning tool for articulating, it can be used with pulleys in various configurations or fastened to a shaft as you have here.

[jrflorentine]

Wow, Meccano looks awesome! It's my first time seeing it!
I 100% agree with you on string--recently on Twitter I've seen people use it to make flapping wings and articulated tentacles!

[not.sure.dojo]

Such a fun project. I have got to make one of these. Except, I dont have a 360° servo on hand. Hmm, I do have a stepper motor so that should work. I suppose I could use a traditional servo and some gears to get the 360° rotation. Time to get creative.

I may add some LEDs to the eyes. I need to see if I have any RGB LEDs; green for happy, red for angry and blue for calm, I suppose. If I do that, then I suppose I should add another servo to move the eyebrows up/down. Or, I could just build it like it is and not overdo it, lol.

[jrflorentine]

Servo-controlled angry eyebrows sound HILARIOUS!!!
I think a stepper motor should work? The only reason I used a continuous servo was because I only had servos on hand, and I used a continuous one so that the strings had something to wind around.

[MuthukumaranK]

This is cool!! Your project gives me some more ideas
- Will try to use some polypropylene sheets (regular plastic folders which we can get at stationery shops) for tentacles! They are stiffer and can take multiple cycles of folding / unfolding

- will make the axle attached to servo eccentric so that some tentacles shrink and some tentacles expand for each revolution of servo

[jrflorentine]

Those are fantastic ideas! I'd love to see if you make it with those modifications!

[sigritom]

Awesome!

[Penolopy Bulnick]

This is so fun!

[seamster]

I love this project - excellent, educational, AND just plain fun! : )