Hidden Blade With Extension Concept

my idea of the hidden blade concept.........soon im going to post a vid or steps in the actual creation..

Materials:

*2 ball-bearing sliders(4 if you like duals)
*1 long wide piece of thin flat metal(can be easily bent or formed)
*2 key rings or copper hoops with nylon strings(one short, one very long)
*3 copper beltpiece(the pic will guide you)
*1 elastic piece of flat metal or door hinge
*1 piece of compact, small, heavy metal cube(optional)
*1 short screw with bolt
*2 very long screws with bolts
*2 rubber bands
*1 piece of lightweight knife or a letter opener
*1 pack of epoxy(or any kind of very strong adhesive suitable for metal)

NOTE: remember, after you assemble the parts according to the picture, use the other slider and take of all of its parts except the slider case,its used as a cover for protection of all mechanisms...