The snake cube puzzle is a chain of 27 cubes (3x3x3). The cubes are interconnected by an elastic string running through the middle of each cube. Each section contains two or three cubes. The goal of the puzzle is to arrange the chain in such a way that there will be a 3x3x3 cube. It's not as easy as it looks.
This is just the solution. My version was purchased from Amazon: http://amzn.to/2zYfU7K
I've included pictures for each step. You could also watch the video.
Step 1: Lay Out Flat - Look for This Section
Look for the sections that have 3 cubes next to each other. This is the starting point for the successful completion of the puzzle.
Step 2: First Move - Align the Two 3 Cube Sections
Flip the interior triple section as shown. They will now be alongside each other.
Step 3: Stand Up the Two 3 Cube Sections
Stand them upright where each end of the strands adjacent to the upright portion are on the table side (and not dangling in the air.)
Step 4: Rotate L Section on End As Shown
Step 5: Rotate L Section Again
Step 6: Rotate L Section Again
Step 7: Rotate L Section Again
Step 8: Base Is Complete - Start on Back
Pretty easy from here. Its basically wrapping the strand around the core and filling in as you go.
Step 9: Rotate As Shown
Step 10: Rotate As Shown
Step 11: Keep Wrapping Around
Step 12: Keep Wrapping Around
FYI There is a lot of twisting at this step.
Step 13: Keep Wrapping Around
The final moves for the top of the cube are going to make the shape of a "U".
Step 14: Rotate As Shown
The last leg just rotates in place and you are done.
Step 15: Finished Puzzle
So, now you know!
Step 16: CAD File
I included a STP file if anyone wants to print a non-functional cube.
For a real cube, check here: http://amzn.to/2zYfU7K