Bearings for Z-Axis

My DLP printer has a standard 8mm threaded rod for Z-Axis movement. Initialy I used a Ikea cupboard front assembly bit with a plug glued in as a bearing (pic 1). No good, but it worked. Since I want to increase the precision of the printer, I had my printer print new bearings (pic 2). It shows that everyone can build a DLP printer from scrap materials and then improve it further!