Hey , ive started hearing this pulsating rubbing /grinding noise on my x1c . Sometimes its more of a grinding than this pulsating rubbing noise . Ive been printing with this printer for over 2 months night and day. I followed the wiki on maintenance for the carbon rods and stuff . Tightened the belts and ran the calibration. Still same issue 
any idea where its coming from ? I cant pinpoint it at all . Waiting on bambu support response
June 8, 2023 - YouTube here is the link to the sound
Besides the carbon rods, did you carry the z-axis lead screw maintenance?
By chance, I discovered tiny filament debris glued there and easily missable due to its size.
I currently check after each print.
1 Like
Any resolution on this @Papaa_smirff ?
I think I’ve go the same issue. My printer is about a week old. Printing a LOT in that week but the noise is very significant.