2520 Pin Box

thingiverse

The puzzle box I created for my dad is called the 2520 Pin Box. It's a simple but challenging puzzle that my family enjoyed solving over Thanksgiving. To build this box, you'll need 5 springs with a diameter of 9mm (3/8") and a length of 16mm (5/8"). You'll also need a dowel rod with a diameter of 5mm (1/5") and a length of about 250mm (10"). Here are some tips to help you build the box: Print all the parts, including two identical "box-wall" pieces that need to be mirrored. Clean the dovetails carefully without removing too much material. Make sure the channels inside the Bible are smooth and free of debris. To assemble the locking mechanism, insert the driver pins into the slots at the bottom of the Bible and attach the caps. Then, slide the dowel rod through the thin hole in the Bible and into the driver pins. Cut the dowel to the same length as the top of the Bible. Repeat this process for all five driver pins. Glue the newly cut dowel rods into the driver pins, then remove the caps and insert the springs. Finally, glue the caps back in place. Before assembling the entire mechanism, dry build it first to make sure everything fits together properly. The 2520 Pin Box has seven pins, but only five of them are used to solve the puzzle. This means there are 21 ways to select the five pins and 120 ways to arrange them. In total, there are 21 x 120 = 2520 possible combinations, with only one correct solution.