I've seen many designs for Assassin's Creed hidden blade design, and I think they are all great, but my one peeve was that none of them were truly retractable. They only extended by a coil spring or force, and were pushed back in. I've come up with a design I wanted to test out but have no idea where to find or how to make, a spiral spring, AKA clockwork spring.
The spring is the key to the design and only needs winding once in a while to operate.
It's not the best looking picture I know and it's definitely not to scale but I hope you can make sense of it. The string pulls the bell crank, which allows the snail cam to spin out half a turn to extend, and then again to retract. For safety reasons I didn't make it definitively locking on the opposite side of the cam but another bell crank like mechanism could make it so.
The spiral spring will be attached to the underside of the cam and will keep the force on the cam, which can be wound with the key.
I know it's rough but I wanted to know any improvements on my design that anyone may have and if anyone knows how to make a spiral spring. What thickness of metal and type of metal do I use? Do I just wind it around something or do I have to heat it so when it cools it will keep it's shape? Can I just take apart a tape measure?
I don't honestly think It will only need two scissor mechanisms to extend properly but this is just a representation.
Any questions, comments, concerns, and feedback is greatly welcome.
Thank you all very much.