also a this is a derivative work of thingiverse.com/thing:5995 i stretched them and shrunk them to fit 1/4" bushings
you could combine the parts but i already had the bushings printed for something else.
i didn't want to dissemble my bot to put in the really big z rider assembly just yet, i will wait till it actually breaks before i break it trying to fix it. i looked at just printing the wobble arrestor but it was about a 5 hour print for all the parts, i wanted to have it fixed in an hour or so.
so i looked around to what i had printed, came up with this and hot glued it all together. i went from a pretty extreme z wobble that matched the threads of my acme rods to nearly nothing.
its not pretty but it works and prints really fast and is easy to install and easy to remove.
the 2x2 lego is with both installed
the black 2x4 is with one rod installed
and the mendel part is the excessive z wobble before i put these in.
this is not a permanant solution, just to temp straighten it out as fast as i could