LM8LUU Bearing Blocks - Wanhao Duplicator i3

WANHAO i3 Fan duct
http://www.thingiverse.com/thing:1246425

Di3 v2.1 Spacer for Thorped's Fan Duct
http://www.thingiverse.com/thing:1650495

Use M3 12mm
THK LM 8L ( LM8LUU )
https://tech.thk.com/en/products/thkdlinks.php?id=322

Blog
https://junkhack.wordpress.com/2016/12/11/wanhao-i3-mod/