I made these in order to straighten the threaded rods on my printrbot LC V1. Since I assembled the bot I have noticed that the threaded rod and the smooth rod were not even, (front to back) yet the printrbot stepper mount and smooth rod mounts clearly suggested they should. I finally decided that I could make a part to offset the nut from the center of the x-axis, and this would make them line up more evenly. It did. These work great, in-fact I see less wobble because the threaded rods are no longer pushing the x axis foreword and back. while I know this is far from a perfect fix for z-wobble, this GREATLY decreases it. This should work for those with acme rods with the same sized nuts, I don't see why it wouldn't.
The little ribs that fit where the nut edges used to sit is a very tight fit, and is so tight you will likely have to cut some of it off in order to press them onto the x axis