I came across this link http://www.igus.com/wpck/3665/drylin_r_rjm_01 Then i came across this link http://www.thingiverse.com/thing:24990 Makes me wonder, why do we need to buy bearings again ? All one would have to figure out is what to lubricate it with. As for printing in PLA, i dont see a problem. There is simply not enough friction to create any temperatures that would ruin the bearing. Even if melt point is reached (say printing cylinder 10x10x200) at very high speed(who does that anyway) you can still print another one. PLUS people say its quieter too. Now am not sure what the noise complain all about, but i think its because LM8UU's ware out or ride on none precision rods. What ever the case may be, i think these little slippy sliders are great. You can print 1 two times long so you wont have to have 2 inserted into each end like we all do when we change them. Any thoughts on that ? Has anyone tried these ? I will 100% try these on Z since i run brand new X rods and bearings and my bed printable upgrade is only couple of months old.