Review on Igus RJ4JP 01 08 Printer Bearing Replacement by Daniel Elgee

UPDATE (removed and updated original review) I installed them first to replace all 10 bearings in the original Prusa I3-MK2.5. Everything worked fine and was much quieter BUT I had an issue with my Y axis. After numerous attempts to get the Y axis to pass the self test I finally decided to take everything apart and go back to my linear bearings for the Y axis. Then everything was calibrated and worked for about a week. Finally, there was a creaking sound from the Y-shaped movement. After many confused attempts to figure out what was going on, I took it all apart and carefully examined the Y-bars. It looks like my original linear bearings have damaged the original Prusa stainless steel rods over time. So these new bearings were hanging from a scratch on the connecting rods (hard to find without close inspection). I thought these bearings might be too sensitive to the weight of the print bed, but apparently the issue was unrelated to these bearings. So with some new rods I reinstalled those bearings. No issues with calibration or operation. And everything is quieter. It seems the linear bearings tend to get in the way when something gets stuck there, over time they seem to wear down and scratch the cranks. If you are planning to build a new printer or need a major overhaul I would definitely recommend them. Quiet and smooth operation. UPDATE March 2019 I still like the bearings, but not under the Y-axis moving heating element, it's not the bearings themselves, they are smooth-running and maintenance-free. But with the original Prusa (3 bearings under the bed) I had issues with the bed not pushing the Y-stop. This particular design has steel hinges attached to the print bed structure. If they are "slightly" tightened too much, the ease of movement of the bearings will be severely impaired. If they are too loose, the bearings will wobble. The difference I'm talking about could be 1/4 turn, very subtle. Worse, Prus has 3 camps below. So if you sit too tight, it can affect the movement of the bed. In short, it's highly recommended to use the Z-axis and possibly the X-axis, but I'd stay away from the Y-axis.