Introduction: Chopsticks, the Robot

About: I'm Mario Caicedo Langer (M.C. for short), a Colombian STEAM educator living in Azerbaijan, BSc in Naval Sciences and former Navy officer. I am a CAD and 3D Printing enthusiast and an artist specialized in jun…

Found footage discovered in a smartphone shows the existence of a strange creature, half-robot, half-Chinese-take-out, wandering in an exhibitions center in Baku. The date of the video is October 18 of 2019. However, new evidence found in an old hard drive demonstrates that this monstrosity exists since August 14 of the same year. Government and Asian restaurants deny any knowledge about this situation, but it wouldn't be crazy to assume that aliens are involved.

My responsibility and loyalty is with the human race. So in order to give us weapons against our future Kung-Pao-scented Cyber Overlords, I am finally sharing my knowledge about these hell-spawns. Beware, because from this moment, you won't see your chopsticks the same way again...


This is a simple project. However, and as strange as it sounds, it took me one year to complete and publish it. I had that idea on my mind like for three months, but I used to forget to get the chopsticks (we only order Asian delivery once per month). When I finally got the materials, I had to use the gearbox for another project at office. I finished it in August of the previous year, but it didn't work in a proper way, so more months passed until I improved it. And just know, I decided to publish it. Enjoy!


  • 1 yellow gearbox (hobbyist motor), like this.
  • 1 battery holder for 9V battery, with switch, like this.
  • 1 9V battery (Note: the photo shows 2 AA batteries and a AA battery holder, but believe me, it works better with 9V)
  • 4 chopsticks
  • 1 big red LED
  • 1 330 Ohm resistor
  • 1 discarded charger for cellphone (big enough to fit the gearbox. Actually, I used an old charger for Lego Mindstorms EV3 robot)
  • wires
  • 4 M3 nuts (if you get nylon-locked, much better)
  • 2 M3X10 bolts
  • 2 M3X20 bolts
  • 8 small metal washers
  • 2 pieces of hard metal wire, modeled as little cranks. Check that they can fit inside the axle holes of the gearbox.
  • Optional: 1 microscope lens or any cylindrical piece that looks like a mini-camera, to house the LED
  • 1 pen
  • 1 zip tie
  • Mounting (double side) tape
  • Super glue
  • TOOLS: Dremel rotary tool, screwdrivers, pliers, cutter, soldering iron and tin.

Step 1: The Case

Open the charger using a screwdriver. In case you are dealing with those infamous bolt-less chargers, open it using the Dremel. Be careful! You don't want to destroy the case (or your fingers).

When you finish, remove the inner components and the metal plugs, using the pliers.

Now, open a hole on each side, with enough space for the gearbox axles to go through. Check that the gearbox is fitting and that the axles are not in contact with the case, to avoid friction.

Remove the gearbox, and drill a small hole on each side of the rear part of the case.

Step 2: The Eye

I was lucky enough to have this discarded microscope lens around my workshop. If you have one, great! If not, try a little bottle cap.

In the front of the case, drill a new hole to fit the microscope lens; if you don't have one, make it big enough to fit the LED.

Step 3: The Light

Solder a red wire to the LED's anode (long pin). Then, solder the resistor to the cathode (short pin). After that, solder a black wire to the available pin of the resistor. Insert the LED inside the lens. Probably you will need some plastic piece (or hot glue) to keep it in place.

Step 4: Connecting Components

Probably at this moment you know which part of the case will be the top, and which one, the bottom.

Stick the battery holder to the bottom, using mounting tape. Don't stick it to the switch area, but to the opposite side (cover). The battery must be in the bottom to keep a low center of gravity and better balance.

Connect the red wires of the battery holder and the LED to one pin of the motor in the gearbox, and connect the black wires to the other pin. Test that the motor and the LED are working. If you grab the case and have the robot's eye facing to your right, the axle must rotate clockwise. If not, change the polarity (connect the red wires to the second pin, and the black wires to the first one.)

Step 5: Closing the Case

Make two small holes on top of the case, big enough to pass a zip tie.

Attach the gearbox to the case using the zip tie, and cut the remaining part.

When everything is working and firmly attached, close the case.

Step 6: The Cranks

Insert a crank on each hole of the gearbox's axle. To permanently attach them to the axle, use super glue. Be careful! Too much super glue will jam the mechanism. The best way to apply the glue is putting a drop in the tip of an old blade, and then placing that drop in the space between the crank and the axle's hole.

The cranks must be placed in an alternate way: one facing forward, the other one facing back.

Step 7: The Chopsticks

Take four chopsticks. Using the Dremel, drill one hole on the top part, and one hole on the middle of each one. Be careful, or you can damage the chopsticks.

Step 8: Back Legs

Take the M4X10 bolts and two metal washers, and attach two chopsticks to the rear holes of the case, through the middle hole.

The chopsticks must be close to the case, but able to rotate freely.

Step 9: Front Legs and Improvements

Insert the remaining two chopsticks in the cranks, through the middle hole.

On each side, join the top ends of the front and back chopsticks passing an M3X20 bolt, two washers and fasten that union with an M3 nut; not too loose, not to tight.

To keep the front chopsticks from falling off the cranks, take a pen and cut two little segments from the ink tube, and make a cut along them. Put a segment at the end of each crank.

Test your robot's movement. If it keeps falling, try cutting the ends of the chopsticks. Also, you can try adding a drop of hot glue on the tips of the front legs, to give more traction.


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