Introducing the BlueFlux, a butterfly knife trainer for the safety-conscious and the style-savvy. It's a 3D-printed nod to the classic balisong, minus any sharp edges, because the only thing we're cutting here is the tension with a little humor.

Design Digest:

The handle's got cutouts that aren't just for show – they keep things light enough to make you forget you're holding anything at all.
The blade? It's as blunt as a toddler's honesty and features a nifty transparent inlay for those who appreciate a bit of flair in their flip.

Assembly:

Filament: I recommend using PLA for the handle for its vibrant color options and a metallic filament for the blade to get that shiny contrast.
Bill of Materials:
2 x 3mm screws (12mm length)
2 x 3mm nuts (for a snug fit)
Screw it all together, and voilà, you've got a trainer that's ready to flip, minus the trip to the emergency room.

Printing Advice:

If your printer is MMU-capable, grab the provided 3mf file for a seamless print with the blade insert.
For single-extruder printers, use the 'blade-singlecolor.stl' file. You can still achieve the visual effect with a filament swap at the right layer.
Recommended layer height is 0.2mm, and you won't need supports.
If the first layer is playing hard to get with the bed, a brim might help.

Happy printing and flipping, and remember – in the world of balisongs, style is just as important as skill!

PS: Also provided the Blade in a alternate orientation. To be honest I'm not sure what is the most cool looking, so I provided both. They are marked with -alt in the filename. Enjoy.