Three Dial Geared Puzzle Box [gearbox]

Being a little addicted to my Trotec lasercutter, I had to design a puzzle box.

This box has three dials, connected with each others with gears. The middle gear is missing two teeth to make it possible to scramble the code.

To open it, you first need to know the code and than you need to manage to enter the code. When you turn one dial, the next one will turn in the opposite direction at an other speed. When the two missing teeth are at the next gear, you can turn it freely to scramble the puzzle.

Materials:

• 4 mm wood (30 x 30 cm)

Tools:

• Lasercutter
• Wood glue
• Clamps

The design is to fit on a small piece of material.

The red lines are cut lines and the black is etching.

• Glue the the part with the big rounded hole on the bottom of the marked top piece with the tree holes.
• Glue the round pieces on the marked circles on the gears.
• Glue the half circles that are marked with the small gears on the small gears accordingly.
• The two other half circles can be glued to the markings on the back of the big gear.
• Put the discs on the gears in the holes on the top plate.
• Glue the two pieces with tree half holes on top of the gears. (don't glue the big gear stuck)
• Glue the three dials on top of the round disc. Be sure that the slots on the back are all lined up and put the disc in het position that you want the puzzle to be solved. (in my case that is 10 - 10 - 10)

• Glue the inner drawer together. (be sure to put the indentations on the outside)
• Glue the four small studs in the in the indentations.
• Glue the three sides (bottom and sides) of the outside together, using the drawer as a template.
• Glue the finished top on top. (take care not to glue the drawer stuck)

• Put some talcum powder inside if the gears are hard to turn.

Turn the two outer dials in the same direction, and the middle dial will turn in the other direction slower.

At one moment you will feel that one of the outer dials can turn freely. This is to scramble the puzzle.

After the scrambling of the puzzle it is hard to open it again, even if you know the code.

What would I do different next time:

• A little more teeth would make the puzzle even harder.
• The design should have a little more room for the gears, drawer and studs to move smoothly.