how to make a moving piece that will move both ways with one crank? Answered
im going to make this knex thing, basically an automatic knex gun, where there is a cross bow like thing at the front, and a slide has a catch that will get the bow, and when it gos backward far enough, an arrow will automatically load, and the catch ill go down, so te rubber band will snap back, and shoot the arrow. i can put a pic in the comments. anyways, what i need, is a way to make the slide go back and forth, but only spinning the crank one way.