Making the Rube Goldberg box
Duration: ~1 hour
|Step 1| - Make the chute
Goal: We need a chute to drop a weight down to turn on the fan.
Materials: scrap cardboard, hot glue, scissors
- With your scrap cardboard, measure and cut 3 rectangles that are all 10 inches long by 1.5 inches wide.
- Hot glue the long edges together to form an open chute, so that your chute mimics a box without its fourth side.
- Cut one smaller square, about 1.5 inches by 1.5 inches, and glue it to the bottom of the chute.
Parts for making the chute
|Step 2| - Attach your servo
Goal: The servo needs to hold the weight up and release the weight down the chute.
Materials: servo, popsicle sticks, hot glue, cylindrical weight
First, start by opening your servo package. Inside you will probably find multiple extensions for the servo. Choose the one that has only one arm.
Glue the chute together
Cut 2 inches off a popsicle stick and hot glue it to the servo arm.
Cut the servo stick
Hot glue the servo to the right side of the chute. Cut a slit in the cardboard so the servo can rotate in and out.
Attach the servo to the chute
|Step 3| - Add the pushbutton
Goal: When the weight drops, it will land on the pushbutton that turns on the fan.
Materials: chute, hot glue gun, button
Cut a small triangle in the bottom of the center piece of the chute.
Pushbutton for the bottom of the chute
Slide the pushbutton (facing up) through the triangle hole and glue to the bottom of the chute. Try to keep it centered on the bottom piece.
Glue the pushbutton to the bottom of the chute
Later, the chute is mounted (with a tilt) to have your metal cylinder fall from the top of the servo and roll down the chute. It pushes the pushbutton down when it stops at the bottom.
|Step 4| - Attach your battery case and board
Goal: Attach the Adafruit Circuit Playground Express and battery case to the side of the chute.
Materials: chute, battery pack, Adafruit Circuit Playground Express, hot glue
Use scissors to pry off the clip on the back of your battery pack. Remove any remaining tape too.
Connect the battery pack
- Hot glue this side of the battery pack (opposite the on/off switch) to the upper left side of the chute.
- Hot glue your Adafruit Circuit Playground Express on the other side, right below the switch with the battery connector on top.
Attach the battery pack
|Step 5| - Set up the fan
Goal: Wire up the fan and connect its batteries.
Materials: jumper wires, alligator clips, fan, batteries for fan
Note: if the fan you’re using requires multiple batteries (if your fan needs more voltage to run than just one battery) you must connect them in series. To do so, use an alligator clip to connect the positive on one to the negative on the other (white alligator clip). Now one battery will be left with an open (+)(red) and the other with a (-)(green). These are the new power (positive) and ground (negative) terminals.
- Find the two wires coming out of your fan. Connect the red one directly to the positive terminal on your battery using an alligator clip.
- Connect the black wire to one of the two wires extending from your pushbutton (it doesn’t matter which one).
- Connect the other wire from the pushbutton to the negative terminal on the battery.
Connect the fan and batteries
|Step 6| - Connect the force sensor
Goal: Connect the force sensor so it will start the servo.
Materials: ribbons, force sensor, alligator clips, hot glue
- First decorate the force sensor to disguise it. Have fun- be creative! Here we used ribbon bows.
- Connect an alligator clip to each of the two connections
Force sensor parts
Connect alligator clips to the force sensor
|Step 7| - Connect the servo and force sensor
Goal: Connect the force sensor to operate the servo.
Materials: main chute, alligator clips, force sensor
- Connect the black wire from the servo to the GND pin on the board.
- Connect the red wire to the 3.3V (power) pin on the board.
- Connect the yellow wire to pin A3.
- Connect one side of the force sensor to ground.
- Connect the other side of the force sensor to pin A1.
All the connections
Pin connections on the board
Tape the wires an clips to the chute
|Step 8| - Assembly
Goal: Put the chute, force sensor, and box together.
Materials: hot glue, electrical tape, scissors, large cardboard box, chute and attachments, popsicle stick
The chute and box ready to go together
First, open up the four corners of one side of the box and glue them out so they extend the box. Open up the back side of the box to make assembly easier, but don’t do anything with it quite yet.
Box opening
Get the scissors, glue gun, and ruler ready.
Tools for the chute
Carefully take the chute and place it inside the box. Glue the bottom of the chute to the bottom of the box. Then, take a popsicle stick, glue one side to the top of the chute, and the other to the top of the box. To make sure the weight falls the way you want it to, adjust the angle of the chute if you need to.
Mount the chute in the box
Take the remaining part of the popsicle stick and glue it to the bottom of the chute. This will hold in the weight after it falls.
Remainder of the stick
Glue on the weight keeper stick
Cut a small hole in the side of the box, and pull the wires and force sensor through. Tape the wires in an appropriate place so the decorated force sensor can be centered.
Tape on the force sensor
Glue the fan near the back of the box to leave room for confetti.
Glue on the fan close to the back
|Step 9| - Decorate!
Goal: Cover the box in tissue paper and hide the wires.
Materials: tissue paper, electrical tape
Use tissue paper to cover the box. For a more discrete look, you can use electrical tape to tidy up the wires.
Decorate!
Complete!
Congratulations! You have completed the Rube Goldberg prank box make challenge. Now, cut up the leftover tissue paper to make some confetti.
Get some confetti
Load your prank box with the confetti to get it ready!
Load the confetti into the box
Ready to do some coding? OK, good…connect the Adafruit Circuit Playground Express to your computer to get started.
NEXT: Code