False Imprisonment Puzzle

While wandering through medieval cities and inspecting the architecture, the metagrobologist David Singmaster noticed an interesting pattern on some of the metal bars that fortified the windows. They were woven together in a seemingly impossibly way. How were these constructed?

After making a model, he soon uncovered its secret and thought it would make a fine puzzle.

More information from Singmaster can be found in his article here (he sadly passed away a few years ago). He even uncovered that M.C. Escher featured them in some of his artwork, although modified to be actually impossible to disassemble. So unfortunately the poor guy behind the bars will not be able to escape.

But fortunately for you, escape is possible! Can you figure out how it goes together (and comes apart)? I also added another little challenge - can you put the bars into the square frame so that it remains securely attached? 

Goal 1: Figure out how to assemble the bars into a lattice.

Goal 2: Now assemble the bars - but also attach it to the square frame.

Printing Instructions

Print the 8 sticks (wire bars) and the square frame. No supports needed, although you need some bridging for the frame.

Solution

Since the objectives of the puzzle may not be entirely clear, I put together a solution video in case you get stuck. But give it a go before taking a look!