About this 3D model

I wanted to give a test drive to the different printable lm8uu designs available on thingiverse, so I compiled 14 of them in a single plate. Note that some of those might be a bit fragile when printed with a 0.5mm nozzle, for lack of infill between shells. I only included stl files which were ready to print in a lm8uu format. Some other designs exists that need repair or customization to be used as a lm8u, I didn't select them here, you can find some in my bearings collection http://www.thingiverse.com/DeuxVis/collections/bearings/ I haven't done the testing / selection part yet, I'll also include some bearings milled from wood in the process. I plan to try different materials too. PLA is the usual recommendation for printable bearings, but polystyrene, PET, polycarbonate could be good too as they are very rigid. I think I read somewhere about using nylon - as it is auto-lubricating - but I have my doubts as it may be very sticky on the rod (being soft).