A spinning version of the cross/boomerang sub-weapon in the Netflix Castlevania show. The blades rotate, emulating the impossible movement seen in the show (no really the secondary set of blades appears out of thin air when all 4 blades are extended). Submitted for the Elegoo x Snapmaker MOVEIT 3DP Contest.

To print this rollers.stl, inner.stl, and outer.stl MUST be printed together (all centered) without supports if you want the rings to rotate.

Print:

inner x 1 (centered)
outer x 1 (centered)
rollers x 1 (centered)
spikes x 4
blade1 x 4
blade2 x 4
rollercap x 1

Assembly is as follows. The inner,outer,rollers are centered together and printed without supports in any build space. There is enough tolerance in the models for the rings to  rotate, but not slip past each other. If this is not the case, dial in the printer tolerances before attempting to print again. 

After removing the print from the build plate, individually move the rollers (there are 46 of them and I found that gently pushing on them with a screwdriver frees them) and add a lubricant (white lithium grease) so that the outer ring spins freely from the inner ring and handle. 

Carefully glue the roller cap ring to the outer ring edge. Do not get adhesive into the rollers or onto the inner ring edge. 

Glue the backs of the spikes and blades together. Glue the spikes to the outer place on the ring. They should fit snugly into the gaps. DO NOT get adhesive into the rollers or inner part of the ring. The piece should only be adhered at contact points on the rollercap and outer part of the ring. 

Glue the assembled blade2 pieces onto the spikes and outer ring. 

Glue the assembled blade1 pieces at a 90 degree space from the other blades. Once again, ONLY get adhesive on the rollercap and outer parts of the build.