Ultimaker printed bushing blocks
thingiverse
Bushing blocks fits to standard 11mm outer diameter and 12mm long bronze bearings. I used the belt tensioner idea from user MoonCactus (with minor changes):http://www.thingiverse.com/thing:45236 For tensioning your belts you can use his bananas. Second picture (mounted block) was taken after about 8 months - still works without any problems. Instructions For use in heated chamber ABS is recommended.
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