i know that the handles are not very stable, the smoothness of opening is not very good, and its very large. aside from that, this butterfly knife actually has a recognizable blade and handles that cover the blade (somewhat) when closed. plus, it even locks open.
and sorry for any blurriness.

Step 1: Blade

the broken 90* connector is not a design requirement, it was simply the piece i had available when i built this. a 45* could also be used in its place.

Step 2: Handle 1

once again sorry for the blurriness
the two pin clips are used to prevent overturning when opening
the piece between the two 90*'s is the female connector for a ball joint