Piston Cage Puzzle

A deceptively simple desk puzzle: a piston is trapped inside a 5-rod cage. Your goal is to free the piston from the cage and then put it back inside. Prints fast with no supports or special configurations, glues up cleanly, and is great for makers of all ages.

⚠️ Spoiler note: The assembly steps reveal the trick to the puzzle!

What to print (quantities)

• 2× Base parts
• 5× Pole parts
• 1× Piston Loop
• 1× Piston Base
• 1× Piston Axis

Assembly:

Assemble cage and piston separately.

1. Identify the hole marked with a small circle on each base. 

   Align the marked hole on both bases so that a single pole is glued to both marked holes.

    

2. Glue the 5 pole parts into the bottom base. Maintain the layout so that the same pole has the marked hole on both ends. 
   Put a tiny drop of glue on the top of each pole and close with the other base.

    

3. Prepare the piston: insert the small axis through the Piston Base and capture the Piston Loop. Glue the axis only to the Piston Base so that the loop can swing freely.

Solving the puzzle you should not apply any force when getting the piston out of the cage. 
If you see that some force is needed then you are doing something wrong.