Impossi-Puzzle

Impossible, or is it?

Not really a puzzle as such, more of a fiddly-thingy-majig that is almost impossible to make the conventional way. Drawn up on OnShape then printed from one STL file. A 4 hour print. Not an original idea, but I have seen it done previously, so I thought I would have a go myself (rather than downloading somebody else's STL file). All fun a da workhouse.