The cardboard safe is intended to keep the things you want safe and secure inside of it. You need a lot of cardboard. For the cardboard you need 2 50x80 cm of cardboard, 1 meter of PVC with a diameter of 12mm, 2 popsicle sticks, hot glue sticks, a metric ruler, a pencil compass, a pencil, cutter knife, hot glue gun, and a brush.

Step 1: Step 1: Making the Gears

In this step you need to make two gears. For one gear you need 3 circles with a diameter of 80mm, one circle with a diameter of 30 mm, and one rectangle of 12x 260mm. From there glue the circles on top of each other with hot glue and have the smallest circle on top.

After, in order to mount the gear teeth, remove an upper layer of the cardboard strip you cut out. Get a wet brush and brush the top of one side of the strip, and peel off. From there, glue the side of it around the circles that are already glued together.

With your box cutter, cut 2 20 mm of pvc. Poke a hole with a pencil through one of the gears. from there stick one of the PVC through the middle and hot glue it together. The second PVC is used in another step.

Step 2: Step 2: Shaping the Safe Door

Using a cutter, we start by cutting the outer frame size 34x42cm and then cut the cardboard to form the door size 25x31cm.

From here, we cut a hole at the stop right corner that is 8.5 centimeters in and 8 centimeters down.

After Stick the gear with the PVC tube in it already down through the hole.

Right next to the gear that was put through the hold, glue the PVC tube from the previous step right next to the other gear in order of them to be able to spin.

Step 3: Step 3: Building Tongues Lock

Using a cutter, cut the pvc tubes of 12mm diameter into pieces of the following length: 2x28cm, 18cm and 35mm.

To build a rack mechanism, cut 2 rectangles of cardboard 12x6mm, remove the upper layer to find the teeth. They are glued on end of the internal faces of the two tubes.

Step 4: Step 4: Shaping Locking Wheel

Start by cutting the cardboard in 4 circles of diameter 30 mm. then, we will cut each of the 3 circles into 3 pieces: two half circles and a central rectangular piece of width 14mm. The semicircle pieces are glued superimposed.

Step 5: Step 5: Mounting

We start by making two holes for rotation axes of the two locking wheels, always we can use a pencil for the perforation. After the installation of the two locking wheels, the tongues lock is placed in its position as shown in the attached picture. We can if we want to build a box that covers all the locking mechanism.

Step 6: Step 6: Front of the Door

For this step I cut 3 circles out of cardboard. 2 of them at which of 25mm of diameter, one of 50mm in diameter. From here I numbered them both 1-12. I glued the circles onto the PVC that went through from the holes we have on the inside. In the front of the door you can really decorate how you would like it. For me, I made it look like it had more security measures.

Step 7: Step 7: Making the Hinge

For the hinge of the door we used duct tape half on the door frame and the other half of the door. We also used some hot glue to reinforce it.

Step 8: Step 8: Making the Rest of the Walls

In this step we have to make five other walls because we already have the door. We have to make the back side of the safe which will be 42x34cm. We have to make the top and bottom which is 42x30cm. Finally, we have to make the two sides which is 30x34cm. To make them come together, I hot glued the edges in order of them to form the safe.

Step 9: Step 9: Enjoy!

This is all you have to do now, it should be fully functionable. I did not come up with this idea, I used another page and made it to my own version of it. Now go enjoy!