Introduction: Wacky Wire Carnival Game

About: I am 17 years old. I moved to Mexico 16 years ago to help the indigenous Tarahumara group here in Chihuahua. The people here in Mexico are amazing. My dad owned a very successful business in Colorado Springs, …

Why did I make this game?

We have a ministry here in Mexico. We work with an indigenous people group called the Tarahumaras. We specifically focus on the children. A while ago we decided to host a carnival for all the kids and I was put in charge of making this game. It turned out great! The kids loved it even though they found it difficult. I wish I would have taken photos of it in use however the Tarahumara people are very uncomfortable around cameras so I wasn't able to take any good photos or videos.

The Design Process:

For the entire process of designing and building this game, I used Fusion360. If you want to see the full modeling process you can open the provided .f3d file and see the entire design process from start to finish.

Table of Contents:

  1. Step 1 Wiring
  2. Step 2 Bending the Wacky Wire
  3. Steps 3-5 Assembling 3D Printed Parts
  4. Step 6 Handle
  5. Step 7 Wooden Structure
  6. Step 8 Final Assembly

Print Files:

I have included the correct files on each step, however, the full assembly and .f3d files can be found on

The Print files can be found


You may wonder why all these parts seem very scuffed and torn apart. As I was in a time crunch I didn't have time to reprint all the parts to get the perfect fit, so I had to cut some pockets, drill some holes, etc... But the files I included are edited and the fitment is perfect. I just haven't had the time to reprint everything.



The tools needed are just basic wiring tools, basic woodworking tools, and a 3d printer. I have included all the specifics however chances are you already have many of these items.

Tools Needed:

  1. 3D Printer
  2. Drill
  3. Phillips Bit and a few Drill bits
  4. Circular Saw, Handsaw, Table Saw, or Jig Saw. Anyone works
  5. Soldering Iron
  6. Allen Keys
  7. Welder (Optional)
  8. Electrical Tape
  9. Sharp Knife or Scissors
  10. Wire Strippers and Cutters

Hardware Needed:

  1. 11 M4 Bolts Short (Medium)
  2. 10 M4 Threaded Inserts (Short)
  3. 1 M4 Nut (For Contact Terminal)
  4. 5 M3 Bolts (Medium)
  5. 5 M3 Threaded Inserts (Short)
  6. 2 M2 Bolts Long (For Mounting DC motor)
  7. 2 M5 Bolts (1 Long, 1 Short)
  8. 2 M5 Threaded Inserts (Short)
  9. Lots of Wire
  10. Solder
  11. Shrink Wrap
  12. 5mm Rod (Used as the Wacky Wire)
  13. 3 Bearings (10mm OD, 5mm ID, 4mm Width)
  14. Large 3/8in Bolt (Optional)
  15. Large 3/8in nut (Optional)
  16. 1 2x4" of Wood
  17. 1 4x8' sheet of plywood 1/2in thick
  18. 1 4 Hole Bracket, Can be found at many Hardware stores

Electronics Needed:

  1. 10 kΩ Potentiometer
  2. 2000 uF Capacitor
  3. Red LED
  4. nMOS Transistor (MOSFET)
  5. batteries, AA
  6. On-Off Switch
  7. GM9 Geared DC Motor
  8. 1 MΩ Resistor
  9. 470 Ω Resistor
  10. Piezo Buzzer


Step 1: Wiring

How to Wire this Project:

The wiring may seem daunting at first. But the circuit is straightforward. There are many different ways to wire this. Some may find it easier to use an Arduino, while others rather not have to deal with a microcontroller. This part is entirely up to you, and both have Pros and Cons. I opted to make my circuit without a microcontroller. I have included a link to the Tinkercad circuit design so you can play with it and understand how it works. I also provided a link for a tutorial on how to wire the motor controller as it can be a little difficult to understand.

Basic Circuit Connections:

The 2nd and 3rd images show the motor circuits. The 2nd image is just the basic circuit, whereas the 3rd image includes a switch and an LED to indicate power. I would highly recommend looking at the images provided, the main circuit, and the links I provided above to understand the pinouts. But here is a basic pinout for the main circuit:

MOSFET Connections:

  • Gate Pin (The Left Pin): Connected to the Wiper Pin (Middle Pin) Of the Potentiometer. Connected to the 1m Resistor(The 1m resistor is connected to the negative terminal on theBattery Box)
  • Drain Pin (The Middle Pin): Connected to Side B of the Switch. (The Switch is connected to the positive terminal on the Battery Box)
  • Source Pin (The Right Pin): Connected to the positive terminal on the Motor

Potentiometer Connections:

  • Terminal 1 (The Left Pin): Connected to the negative terminal on the Battery Box.
  • Wiper Pin (The Middle Pin): Connected to the gate pin on the MOSFET (Mentioned in the "MOSFET Connections)
  • Terminal 2 (The Right Pin): Connected to 470ohm Resistor. (The 470ohm resistor is connected to Side B of the Switch)

LED Connections:

  • Cathode (The Short Pin): Connected to the negative terminal on the Battery Box
  • Anode (The Long Pin): Connected to the Side B of the Switch

Switch Connections:

  • Side A: Connected the positive terminal on the Battery Box
  • Side B: This is where all of the connections to the Switch mentioned above actually connect to.

Motor Connections:

  • The Positive Terminal: Connected to the source pin of the MOSFET
  • The Negative Terminal: Connected to the negative terminal of the Battery Box

Buzzer Connections:

  • Negative Terminal: Connected to the Handle, Connected to the negative terminal of the Capacitor (The wire that connects to the Handle needs to be around 6ft long)
  • Positive Terminal: Connected to Side B of the Switch, connected to the positive terminal of the Capacitor (Remember this wire has to be 2.5-3 ft long)

Wacky Wire Connection:

  • The Wacky Wire is connected to the negative terminal of the Battery Box (This is done by utilizing one of the holes in the metal four-hole bracket, See more in step 8)


The wiring diagram includes two circuits. The buzzer and motor circuits. The motor circuit is fully housed inside the Electronics box. The buzzer circuit is housed inside the Buzzer Box. Two wires connect the circuits. The positive wire from the battery box goes directly to the positive terminal on the capacitor in the buzzer box. Then a ground wire directly from the battery connects to the "Wacky Wire". Then the handle is attached to the ground terminal on the capacitor via a wire. This way when the handle makes contact with the "Wacky Wire" the current passes through which triggers the alarm. Again this is all explained in the TinkerCad Circuit. (See step 8 to see how the ground wire attaches to the Wacky Wire)


Step 2: Bending the Wacky Wire

Please Watch the Video

I was not able to document this process very well, but the video explains everything you need to know before bending the wire.

The Bending Process:

If the 5mm rod you bought is for some reason hardened, then it is necessary to do hot bends. This means using a torch to heat the metal and bend it. Try your best to avoid this!

The 5mm rod should be easily bendable by hand. If necessary you can use hammers, vices, pliers, etc...

Try and make some coils, twists, turns, etc... Make it interesting. This step is totally up to you and your preferences. But here are some tips to keep in mind:

  • Keep the two ends of the wire in the same axis (So that one end isn't offset from the other, this will cause wonky movement, rather than the desired "wacky" movement)
  • Keep the center of mass in line with the main axis (This means you don't want a bunch of weight on the bottom and none on the top, because then the rolling motion will start slipping and causing problems. You can test this by holding the two ends of the wire and seeing if one side always rolls to the bottom, then bend accordingly. You want to look for a nice smoothing rolling motion with no biases)
  • Don't make the coils too tight (Me and my dad got too ambitious with the coils and made them way too tight, which made it nearly impossible to finish, so start easy. You can always go in and add more bends later)

Step 3: Assembling the Main Roller


  • 5 M3 Bolts (Short)
  • 5 M3 Thread Inserts (Short)
  • Electrical Tape
  • Main Roller Hub (3D Printed)
  • Main Roller (3D Printed)

Process: (Follow the Order of the Images)

  1. Install all of the threaded inserts into the 5 recessed holes in the Main Roller Hub
  2. Bolt the Main Roller into the Main Roller Hub with the 5 M3 Bolts
  3. Use the Electrical Tape to wrap around the channel on the Main Roller in order to improve its grip (Cut of the excess with a knife)
  4. Finally, insert the 5mm Wacky Wireinto the Main Roller Hub. It should be a very tight fit


Step 8: Final Assembly

Bracket Assembly: (Follow the Order of the Images)

  1. Drill out the top hole of the four-hole bracket so that the 5mm rod spins nicely inside while maintaining full contact.
  2. Drill out a large hole in the wood where the fourth hole of the bracket is. This way you can bolt on a wire using an m4 bolt with a nut. (See the bottom part of Image 1) This allows the "Wacky Wire" to be grounded. This way when the handle makes contact with any part of the wire, current is allowed to pass and the buzzer goes off. (See the 1st and 2nd images)
  3. Screw the Four Hole Bracket into the proper place, Use only the two middle holes (So that it is in line with the "Wacky Wire", see the 1st, 2nd, and 3rd images)

Attach the Electronics Box:

  1. Cut out a section of the 2x4 to allow the Electronics box to sit flush (See image 4, See "Step 7 Video")
  2. Screw the Electronics box into the 2x4 using the pre-printed holes. Note: My screws are in a different place which required me to remove one of the rollers. In the updated design this is not the case. (See images 5-6)

Attach the Buzzer Box:

  1. Screw the Buzzer Box into the main structure using the pre-printed holes. Note: You want the user to be able to see this box since it lights up (See image 7)

Place the Wacky Wire and Handle in Place:

  1. Set the Main Roller (with the wire attached) on top of the Motor Assembly (See image 6)
  2. Insert the other end of the Wacky Wire into the bracket. Note: Be sure to have the handle on the inside of the wire to use. (See images 8-9)

Step 9: Final Product!

I hope you enjoyed this project!

Make this project how you want to do it. There is no right or wrong way to do it. Add little customizations and uniquely bend the wire, paint the wooden structure however you want. Build the wooden structure however you want. I have provided the basic blueprints, but you have the power to make this project into so many different and unique things. Have fun building this project.

If you have any questions, concerns, or helpful information feel free to leave a comment!

Arcade Student Design Challenge

Runner Up in the
Arcade Student Design Challenge