Note this has been modified Using this in 2 axis means the z-stage can become stuck and rise unevenly in the diagonal accross the platform due the the LM8UU not rising at the same time. i put this down to the flexibility of the acrylic axis and that the off centre weight of the printed stepper extruder means uneven forces act differntly on each axis. Therefore i recomend only fitting one axis to limit motion and using the z-wobble arrester on the opposing corner. Video - http://www.youtube.com/watch?v=KL301WaB8MII have suffered wobbly z axis for a while now, and wanted more accuracy than the wobble arresters could provide (http://www.thingiverse.com/thing:2151) I decieded i wanted some smooth rods to limit the z axis.Previous designs were combersome and had a few parts. I wanted something simple and easy, not to mention got rid of the z axis bars as they were slightly kinky (and not in a good way ;-P )Using designs: LM8UU holder by Gregfrost, 8mm rod mount by twotimes and Small makerbot z stage 'U' by langfordw. http://www.thingiverse.com/thing:9871 http://www.thingiverse.com/thing:4617 and http://www.thingiverse.com/thing:926 I combinded these into the parts below.This is a bit fiddley upgrade and requires a few hours modding, but results are astounding.The green ring (from follow focus) has visable ripples, as too has the 'the pink panther woman'the other pics are of the 8mm low rider im printing after this mod, and the results show for them selves.Video available from: http://www.youtube.com/watch?v=KL301WaB8MIThe video shos the fitting of this part.Get hold of 330mm smooth rod (8mm) Print 1 off LM8UU runner Print 2 off 8mm z axis runner Print 2 off x rod mountRemove 1 Axis rods, and remove the wooden square bearing holders (but save these)Put LM8UU bearings into lm8uu runner (you may need to clean the overhang in this part, or insert the bearing during the build)Bolt the lower x rod cap into the makerbot in replacement for the lower z axis bearing.Bolt the 2nd x rod mount on to the top underside of the makerbot lid.Bolt the LM8UU runner to the z stage.Print a z axis wobble arrester - http://www.thingiverse.com/thing:3057 and fit to the opposite diagonal threaded axis.Thread smooth rod into top x mount, through the LM8UU holder and into lower mount and tighten down these mounts.Remove the screw thread axis wooden 'u' and replace on underside with the 8mm z axis runner.You may need to add a second nut and screw to this axis for more accuracy (see picture) add a spring in between these nuts.Put the smooth rod belt pulleys onto the smooth rod, these are free to move.Print and admire your wonderfull problems have gone!