"Has anyone tried piano wire for the springs?"
Yup. Used piano wire on my last camera and it worked MUCH better than flat springs but you have to run the GG frame in some kind of guide because the round wire springs will bend in any direction.
Yup. Used piano wire on my last camera and it worked MUCH better than flat springs but you have to run the GG frame in some kind of guide because the round wire springs will bend in any direction.