It's one of the 507 Mechanical Movements. This is a 2:1 roller gear reducer. Also derived from the plans in the book "Making Mechanical Marvels in Wood".
I printed everything at .2mm layer height.
You might have to put a dab of superglue on the square Drive Shaft ends that fit in the Spider and the Crank, and the square end of the Disk Shaft.
The three rollers should spin freely on the three shafts of the Spider.