![[Challenge] Weird assembly — I think this will be a hard one :)](https://i.imgur.com/68pVqrW.jpeg){kind=link}
Some light hints that may point you in the right direction:
Hint 1
The assembly is a part of a larger machine.
Hint 2
Several assemblies are meant to move side by side in unison.
Hint 3
The square-ish shaped piece is plastic that will wear down and be replaced.
Is it a machine for folding envelopes or cardboard boxes?
Related to envelopes, but not for folding.