Impossible Cube

I can't remember where I saw a version of this puzzle, but the concept fascinated me. I was drawn to it because this object so misleads the thinking process when trying to figure out how to separate the two parts. But then the model formed in our minds is based on what we see. The brain completes the rest including hidden features. So using fusion360 I set off to design the object and test it. I made several versions of the lock inside the object, This version works best. This particular lock configuration disguises the orientation in which you need to hold and manipulate the object when unlocking it. It also makes it less likely that someone accidentally succeeds, this happened in the first configuration I designed. I also found that it is not easy for people to work out what the precise movement is even after a demonstration (performed theatrically).
Now for what you need. This thing is made up of 7 pieces, 4 printed, and 3 you have to source (unless you happen to have them).
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