I'm asking for my Dad who is trying to embrace the HA life that I've tried to drag him into . He wants to open/close his blinds using HA and I had originally told him about my Add-A-Motor controllers that I really like but they really are mean for looped drawstring type operations and he has the single string blind (the kind where you pull straight to raise it than yank it 45 degrees to unlock the catch).
Is there a device that can "spool" the drawstring for an aftermarket solution so you don't have to buy a somfy or something?