Print out the components

Blades x 6
Backing x 2
Inner Plate x 2

Clean up the all the small holes so that a piece of filament will snugly fit in. You will use tiny lengths of filament to hold the parts together, and also as guide pins to move the blades.

Clean up the two inner plates so that they fit together. Use acetone or super glue to fix the two plates together. Make sure the blades fit smoothly in the gap. And make sure all the grooves line up top to bottom as best as possible. Clamp the two halfs together with light pressure until dry.

Next insert filament through the tiny hole in each blade, and cut it off leaving only about 1.5 mm on each side. Only leave enough to cleanly side in the grooves of the center plates.

Next insert lengths of filement into the back plate. Then slide the center plate and blades down, inserting the filament through the larger blade holes.

Bring the other back plate down on top, pressing the filament up into the holes one at a time until you can press the top against the bottom.
Ensure everything moves properly, and snip of the excess filament sticking out as flush as you can. Sand down the filament ends to blend and secure them further.

Once assembled, hold the center grip while rotating the outer ring. The action gets pretty smooth after you play with it for a while. A little filing might be required on the inner edge of the blades, if you want the blades to close really snug.

Enjoy!