On the stock HICTOP Prusa I3 printer, the Z-axis threaded rod is supported by sticking it through a hole in an acrylic part. This is a bad idea because 1) HICTOP's tolerances on these parts are not very good and 2) the rod will wobble and wear against the acrylic.
If yours shatters (like mine did) and you just want to replace it, you can print this replacement part.
HOWEVER, since you are doing this anyway, why not do it right? You can replace this part with one that uses an inexpensive 8mm bearing (available for cheap on Ebay) and never have to think about it again. The preferred bearings are type 608ZZ.
z_rod_bearing_support.stl | 183.0KB | |
z_rod_support.stl | 184.5KB |