I printed the original version by DXBLouie but found I couldn't get my LM8UUs into the channel on the idler. I downloaded the SCAD files and think the problem was that the original configuration.SCAD file was set to the wrong bushing type.
In any case, I changed the bushing type in configuration.SCAD and regenerated the STL for the idler and it appears to work now as I was able to snap in the LM8UUs.
It's worth noting though that the LM8UUs I have (from Mixshop.ca) are shorter than the normal ones which may or may not make a difference.
Anyways, I've included the updated SCAD files just in case anyone else runs into a similar issue.
I printed mine in ABS on a MakerBot Thing-O-Matic (HBP, Mk6) with 50% infill, 0 shells.