There are now several types of printable bushings. Thingiverse has several self-centering designs, and bushings that fit in place of LM8UU bearings. This development stub deals only with snap on bushings. (please help by expanding it!)
Great alternative of bearings, if you dont have huge load. VikOlliver inspired me with his set of parts, using PLA "sleds". This is radically improved, tho.
I'm testing them on my mendel remix and they looks pretty good.
Also, it makes whole x-carriage snap on to axis rods :-) Its great if you are experimenting with extruders a lot!!
They sits really nicely on rods. With regular Igus bushings I had a problem, because I dont have bearing rods, it was all little wobbly.
You can see them in action on all my axes of my mendel remix. <videoflash>tyVM3-v84I0</videoflash>
Set your Skeinforge to generate the "holders" only single walled, it ads the springiness. You can see my toolpath n image. If you have problems with it, my settings are 0.4layers, and Widht over thickness at 1.6.
Try them on rod, if they slide too hard, you should use bigger rodsize in .scad file, or you can sand the horns a bit, but sanding isn't the most precise way I guess. If there is still too much friction, try running them back and forth on a piece of scrap threaded rod.
Glue them on :-) Best way it to snap them on rods of final assembly, position them, add glue on tops and then push the main part from top on them.