This is a lego butterfly knife that does tricks. And it's surprisingly fun.
Step 1: Bricks
3 1x16s (with holes)
4 1x14s (with holes)
2 4x6 plates
2 smooth round axles
Step 2: "Blade" and Axles
Get the three 1x16s and put them together so the middle one sticks up 1 stud then put the axles in the bottom two holes.
Step 3: Handle
Get the 1x14s and put them on the axles.
Step 4: Weights
Get the 1x4s then cover the plates with them then put the plates on the handles.
Step 5: Your Done!
Have some fun and try new tricks!