Yep I'm still working on this. I have a new design which fixes the issue you mention. I have put a couple of slots on the underside of the effector body into which you slide the nuts, then you can use shorter screws on each side (one per rod) to firmly attach the rods. I will upload the newer design in a few hours when I have access to the files. There are a few other changes, too; specifically the slots for the tails of the FSRs are a bit too narrow to allow them to push through, and I've made the width of the distance between the rods on the effector exactly the same as the width between rods at the carriage end. The design here doesn't allow correct attachment of the rods; that is fixed in the new design with some conical mounting points that give sufficient clearance. Please watch for a new upload in a few hours.