I have my LR3 up and running (mostly).
I initially had issues with the LR Core rubbing against the braces, and this was fixed by loosening off the bearing nuts as suggested in the doco, however, the rub is back.
At the top of the LR core, there is a nice amount of clearance, not so much on the lower.
I’ve read some posts already and have checked the various related items with calipers i.e. the tubes are 25.4mm (well, about 25.49mm-ish), the braces I printed are the 25.4mm ones, and the bearings are dead on 22mm.
All printed on a Prusa MK3S+ 0.6mm nozzle. Last time I printed a calibration cube, it was all pretty spot on for accuracy.
I’ve also tried a variety of combinations of loosening and tightening the bearing bolts at both the top and bottom or the LR core.
Any other suggestions/tips/help?