Introduction: Cardboard Steampunk Puzzle Box

About: Hi! I'm a young DIYer, and I like to dabble in a lot of subjects, from cardboard to baking. While the main focus of this account will be cardboard, I'll try to post the occasional baking and art tutorial. Just…

If you're like me, stuck in lockdown, you're probably still scrounging for all the available puzzles in your house. Hard to come these days, I've found an easier way to get puzzles: make some. Since I especially like puzzle boxes, I decided to attempt my own DIY puzzle box. However, a quick search of the internet revealed no puzzle box tutorials that used my available materials. All ideas were either made of wood or were uninteresting to me. I decided to just wing it, and this instructable is a documentation of my work process. In this instructable, I'll guide you step-by-step through my cardboard puzzle box build. It doubles as a safe guarded by double security. Can you solve it? Are YOU up to the challenge?

Note: Diagrams with specific measurements will be posted in each step.


  • cardboard
  • cutting board
  • utility knife/precision knife
  • hot glue gun
  • wooden skewers
  • Popsicle sticks
  • ruler
  • compass
  • pen/pencil
  • hedge clippers (or something else to cut Popsicle sticks)
  • scissor
  • screwdriver (or something else to make holes with)


  • rotary cutter (for cleaner edges)
  • liquid glue
  • jumbo Popsicle sticks/tongue depressors
  • sandpaper

Step 1: Making the Gears

  1. Cut out three circles that have a 14 cm diameter and glue them together.
  2. Cut out three circles with an 11 cm diameter. On one of the circles, draw two semicircular windows. Copy the design onto the other two circles, and cut the windows out. Glue the three circles together, matching up the window positions.
  3. Cut out three 4 cm diameter circles. Glue them together.
  4. Cut cardboard strips that are a centimeter wide. Peel off the top layer. Glue the corrugated strip, flat side down, onto the outside of the all the layered circles.
  5. Insert 1 cm long skewers into the corrugation of the strips to make them stronger, and less likely to slip when you piece the gears together.

Step 2: Arranging the Gears

  1. Cut out a cardboard rectangle measuring 34.5 cm long by 23.5 cm wide. Draw a design on it, most preferably one with a scale, or straight border.
  2. Arrange the gears next to each other, the smallest gear nearest to the left edge. Look at the diagram pictured for more specific measurements.
  3. Attach the gears to the cardboard using skewers. Glue small cardboard rectangles onto the skewers that hold the largest and second largest gear in place. This will keep the gears from falling off.
  4. Redraw the design on the gears. This will help you realign the gears later on.
  5. Cut a circle measuring 3.5 cm in diameter. Using a precision knife, cut a small notch measuring 0.7 cm deep and 1.1 cm wide. Attach this circle the same way we attached the rectangles.
  6. Cut a Popsicle stick into two 1.3-cm long pieces. Glue the two pieces together, and cut a 0.5-cm long piece from a skewer. Glue the skewer piece to the Popsicle sticks, placing it 0.5 cm away from the top edge and 0.5 cm away from the side edges. We'll call this the slide piece.

Step 3: Building the Lock

  1. Cut a hole measuring 1 cm by 1 cm near the smallest gear.
  2. Insert the skewer part of the slide piece into the 1 cm by 1 cm hole (the skewer part will be nearest to the edge and be seen from the outside).
  3. Cut three 1 cm by 1.5 cm and one 1.3 cm by 2 cm cardboard pieces. Glue the three 1 cm by 1.5 cm pieces around the 1.3 cm by 2 cm piece to create a mini box.
  4. Encase the slide piece in the mini box.
  5. Test it to make sure that the slide piece can slide freely and will stop the gears from turning when inserted into the circle's notch.

Step 4: Assembling the Scale & Key

  1. Cut a Popsicle stick into two pieces measuring 1.6 cm long.
  2. Cut out a piece of cardboard measuring 2.3 cm by 1.4 cm. Make sure the corrugation of the cardboard is vertical.
  3. (Optional) Use paper to cover the top corrugation of the cardboard.
  4. Cut the cardboard piece into three pieces, with the middle piece measuring 0.7 cm wide. This middle piece will be your key. Make sure at least one "hole" of corrugation shows on the bottom of your key.
  5. Check to make sure that the hole can fit over the skewer of the slide piece. You may have to widen the hole using a pencil.
  6. Glue the other two pieces of cardboard onto the Popsicle sticks, one for each.
  7. Make slits where the scale will be on the big cardboard rectangle, and push the scale you have made in between the slits. Leave 1.1 cm of the scale poking out.
  8. Glue the Popsicle sticks to the cardboard, but leave the middle piece unsecured. It should be able to be pried out of the hole by your fingers.

Step 5: Constructing the Second Lock Box

  1. Cut out a cardboard piece measuring 3.5 cm by 3.5 cm.
  2. Find the middle of the piece by drawing an X from corner to corner. Glue a 1 cm long skewer in the center of the X.
  3. Make the piece's sides, which are three pieces measuring 3.5 cm by 2 cm and one piece that measures 2.5 cm by 2 cm.

Step 6: The Second Key Mechanism

  1. Cut two rectangles measuring 3.5 cm long and 0.3 cm wide from a jumbo Popsicle stick. You can use a normal size Popsicle stick, but jumbo ones are usually easier to cut.
  2. Cut out two more rectangles measuring 3.5 cm long and 0.6 cm wide from the Popsicle stick.
  3. Glue one 0.3 cm wide rectangle onto a 0.6 cm wide rectangle piece. Do the same with the other two Popsicle sticks. Make sure the edges line up on both "tracks." The stair-shape of these tracks will keep the lock from slipping in the future.
  4. Glue the two tracks on one of the cardboard pieces measuring 3.5 cm by 2 cm. The 0.3 cm wide rectangle should be on the bottom, glued to the cardboard.
  5. Take one normal sized Popsicle stick, and check if it can slide easily between the two tracks.
  6. (Optional) If there's some difficulty, sand the edges of the tracks and the edges of the Popsicle stick.
  7. Cut the Popsicle stick into a piece measuring 5 cm long. Slide this piece in between the tracks. It should be sticking out from the tracks, since it's longer.
  8. Cut out a Popsicle piece that is 0.7 cm tall and 0.5 cm wide. Glue it to the Popsicle stick located in between the tracks. Make sure it is glued 1 cm away from the bottom edge.
  9. Glue the side with the tracks onto the cardboard square. Do the same with another side piece. Glue the two other side pieces around the square, making sure that the 2.5 cm by 2 cm piece is lined up to allow the 5 cm long Popsicle stick to pass smoothly.

Step 7: Forging the Second Key

  1. Draw a key shape onto two pieces of cardboard and cut it out. I have included a PDF template below for anyone who's interested (for this step, use the template without a hole).
  2. Glue the two keys together. Peel off both top layers of both pieces, so that you're only left with two pieces of paper glued together. You can throw out the corrugated pieces of cardboard out. Keep the flat ones, you'll need them later.
  3. Roll a piece of paper into a 0.8 cm tall cylinder, and use liquid glue to seal it. Let dry.
  4. Using pieces cut from Popsicle sticks, layer both sides of the glued paper with Popsicle sticks. Look at the example above for a better idea. Make sure to leave space where the paper cylinder will be glued. (For the size of the hole, just trace the template with a hole in it).
  5. Glue the paper cylinder to the hole you have designated for it.
  6. Glue the two flat layers that you peeled off before to the Popsicle sticks. This is your finished key.
  7. (Optional) Sand the key down for a smooth finish.

Step 8: Positioning the Second Key Mechanism

  1. Turn the 11 cm diameter circle 90 degrees clockwise.
  2. Draw a keyhole in the space that appears in the upper window. Use your key as a guide to help you get the right keyhole size.
  3. Cut the keyhole out.
  4. Position the box with the lock mechanism directly under the keyhole. This means that the skewer in the middle of the box will be directly under the keyhole. You should be able to insert the key and work the lock easily if your placing is just right.
  5. Glue the box with the lock mechanism to the cardboard rectangle.

Step 9: Creation of the Outer Box

  1. Cut out two 34.7 cm long by 15 cm tall cardboard pieces.
  2. Cut out another cardboard piece, this time measuring 23 cm long by 15 cm tall.
  3. Glue the three cardboard pieces around the cardboard piece with the design on it, the one measuring 34.5 cm long by 23.5 cm wide.

Step 10: Making the Safe Drawer

  1. Cut out a piece of cardboard that is 33.5 cm long and 22 cm wide.
  2. Cut two cardboard walls measuring 33.5 cm by 14 cm (the left and right sides), one measuring 23 cm long and 14 cm tall (the back), and one that measures 23 cm by 15 cm (the front).
  3. Take one 33.5 cm by 14 cm piece and cut a 2.5 cm deep by 1.8 cm wide notch 13.5 cm away from the left edge.
  4. Assemble the box together, gluing all the sides around the 33.5 cm by 22 cm piece we made in the first step. Make sure that the notch is closer to the front than the back so that it will line up perfectly with the second lock.

Step 11: Putting It All Together

  1. Take the outer box and place it directly over the safe drawer.
  2. Cut out a piece of cardboard measuring 23.8 cm wide and 34.6 cm long. Glue it to the bottom of the outer box.
  3. Lock the puzzle box, and return the gears to their original positions.

Ta-da! You've made your very own puzzle box!

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