I wanted to get into 3d printing and so I bought a solidoodle, and i'm having some issues with it.
The rods in it were actually 8.02mm in diameter and quickly (30 hours of run time) wore out one of the 8.00mm bearings on the x-axis. So I am endeavoring to replace the carriage assembly. I ordered 4 Chrome Plated VBX Rods on Amazon.com and two sets of (8) LM8UU bearings (8 needed for my repair (off McMaster) and 8 for a future printer build (off Amazon)). Most of these bearings are VERY tight on most of these rods and they vary somewhat from 7.97mm in dia to 7.99mm. I have found a combination of smaller rods to bigger bearings to that fitup nicely to finish about 3/4 of my machine.
The rods I bought are chrome plated and I think that was my failure.
My question to the RepRap community. Where do you buy your shaft material and is it ground? Also, could I be getting better bearings?