Lock-Block [Neo HB]

This is the lock-block of my hidden blade. Check the other four in my shop: https://www.shapeways.com/shops/sicarius-lair

CAUTION: watch the size of the hidden blade. It's for a 23cm (9,055in) or bigger arm. It measures about 44,4cm (17,48in) when fully extended. Which means you get a 21,4cm (8,42in) blade.

Please note that this is a BETA product, due to money issues, I didn't got one for myself yet. However, I did some simulations in SolidWorks, it everything looks good.

My hidden blade has two working methods. You can keep it inside until you pull a string attached to your finger, so the blade will go out, until you manually put it back in. You can also keep it in with the force of a spring, until you wave your forearm, and the blade will be locked by a metal plate, until you pull it (manually or with a ring attached to it).

Materials needed:

-Paper clip

-Strong line (multifilament line, superline, any strong line that you can make knots with)

-Extension spring or elastic band (nothing to strong, or it could damage the plastic structure)

-Bendable metal plate (to build the lock for the second method, you can use a saw, and get a small piece of it) 

-Small "pen-spring" (that little spring inside those "click-pens")

-Velcro straps/belts, to place it in your arm.

-Some glue