Anyone had grease puddling on top of a z axis lead screw bearing? My left front just starting this about a week ago. The right front looks nice and clean. I did clean the grease off and noticed the end of the screw isn’t centered and is pushing the white seal or spacer to one side. This is on a P1S that’s about two months old.
My apologies for the lack of focus in the first photo.
While I haven’t observed grease pooling on the top of the bearing, the silicon bushing in the second photo is standard. Its purpose is to ensure that the lead screw avoids direct metal-on-metal contact with the bearing. Occasionally, I’ve observed the bushing descending, and in such instances, I use a very thin needle-nose pliers to delicately push it back into place from underneath. It’s worth mentioning that due to the narrower head of the lead screw and the wider section where the threads begin, the bushing is unlikely to fully dislodge unless it is worn or torn.
Thanks! I’ll start with taking another look to see if the bushing is trying to work its way out of place.
Nylon collar starting to oval and fall out. Anyone experience this? : BambuLab (reddit.com)
Here was my post about the bushing 3 months ago before I found out that its normal, but I have a good photo from underneath showing how the bushing looked like it was falling out. But that’s as far as it would move until I pushed it back in place, you’ll see what I mean the first time you do it. 
Good info, thank you. I guess the question now is whether these bushings will be any sort of problem long term. Did Bambu provide any additional advice beyond it’s there for shipping and not a worry?
I don’t think it will be an issue. The lead screw is only moving the bed vertically and does nothing to align it horizontally in the X and Y plane so there is little force in those directions that the white piece needs to deal with. That function is left to the guide rods that are further back and outward. Even the bearing that the soft bushing is inside of really isn’t necessary and would likely work fine if it was a bronze bushing instead, especially the top one.
If something did ever happen to the white rubber sleeve, I imagine Bambu would replace it. But you could probably print a TPU one that works just as good or better. I’ve had good luck printing gaskets/o-rings in TPU and would probably do that instead of waiting on BL to respond.
Thanks! I think you’re right. Following the advice of ExtremeElementz, I just pushed the silicone bit back into place from the bottom side. The piece is so soft I doubt it has any effect and is likely just there to prevent screw’s end from rattling about.
