The brass nut on the rear lead screw that connects to the heat bed failed on my X1C printer with 3,890 hours on it (threads on the inside of the nut are worn, it’s almost totally smooth and the nut slides freely up and down the lead screw) . Also, one of the front brass nuts was found to be very worn, the other front brass nut was okay. (Bambu lab support referred to the part as a bearing) I have kept the lead screws on my X1C well lubricated at all times.
The part is not available from the Bambu Lab web site, I have contacted support to see if I. can purchase replacements, but it looks like that is going to take weeks. Support stated “Please allow me some time to review this further and see if we can source the part directly. “.
I was able to find a part on Amazon that is close, it’s the same diameter, thread specs and takes the same 4 screws to attach to the heat bed slider bracket but is different in height from the original. Original is 11.43mm tall and the replacement is 15mm tall “uxcell 4 Pcs Tr8x8 Lead Screw Brass Nut, Trapezoidal Nut Linear Screw Acme Thread Screw Replacing Brass Nut (2mm Pitch, 4 Start, 8mm Lead) for 3D Printer Accessories” Also the original is symmetrical where the center part extends 3.6mm above and bellow the disk with the screw holes and the nuts purchased from amazon extend 1.5mm above and 9.6mm below the disk. I was able to install the parts from Amazon in my X1C and get the printer working. I think I lost about 6mm of printable Z height due the difference in the nut height, but I am able to print with the X1C.
I suspect that other Bambu lab printers are likely going to be encountering issues with these brass nuts as they wear out. Hopefully Bambu Lab will add them for purchase from their web site, if not then maybe a company like BIQU will start selling them. Until then if you have tis issue and want to get your printer working these nuts might be available from Amazon.
Disappointing to see they dont have the OEM replacement on offer yet, but this is good info and makes sense from a wear perspective. Brass vs steel, 4k hours, yeah.
Out of curiosity, during the course of those 4k hours, what was your cleaning regimen on the Z rods? No blame, just interested in the real world example you’ve shown vs manufacturer “projected lifespans”
I tried several different methods to clean the Z rods, I have used various printed tools with a rag to clean the rods, most recently I have found that gear floss has got them the cleanest. I have been using super lube Synthetic Multi-Purpose Grease on the rods. I cleaned and re-lubed them when the grease looked dark, typically every few weeks and any time I got a message to lube them. Every 500 hours I remove and clean the extruder and do a cleaning of the whole printer and AMS.
Out of curiosity, what do you’re Z axis bushings look like? Mine are made of soft silicone, and have been squished in half due to shaft misalignment with only 20 hours on the machine. I imagine this misalignment would increase the wear on the Z nut, early machines had a solid bushing with less compliance.
<img src = https://etischer.com/dropfolder/fusion360/bushing.png>
The old bushings are slightly different than the replacements, they don’t have a top. When I replaced the z-axis hardware I could not get one of the new bushings to stay in place until I loosened up the screws attaching the bed to the slider bracket, moved the bed to the top, installed the bushing and re-tightened the screws.
could this be actually the one ? its the most i could find out there, it has 4mm from flange to end of nut on both sides, 2026 asked support for replacement they dont even know what nut im talking about when i ask for a replacement brass nut for my z-axis…
Tell Bambu Support you need ( Z-Axis Leadscrew Kit model: FAC067 ) I purchased in July 2025 for My X1-C cost was $35 + $7 Shipping Plus NY Sales Tax.
The kit is very nice and includes the 3 lead screws, 3 lead screw nuts, lead screw nut screws (4 per nut), 6 bearings and 3 bushings. From what I recall the kit had everything needed except the screws to temporarily hold down the heatbed, those screws were shipped with the printer.
The following wiki shows the install procedure:
Just wanted to let you know that I tested the dimensions in the link to an official replacement I have and they look exactly the same. Thanks for finding this. When I had the problem a year ago, I absolutely could not find a 3rd party solution and had to get bambu’s.
Now we just need to find a good 3rd party Z axis lead screw!
actually, somehow my machine with 6400 hours was still in warranty and i just jumped them by demanding to buy them but they asked me for my UID and they just went yeah still warranty, 4 days you have new set and they shipped me but yeah for reference “Z-Axis Leadscrew Kit model: FAC067”
is exactly the needed part
Did you have to replace all 3 in order to get this to work? Or just the one that was worn out?
Thanks
Common practice on wear items like that would be to replace all the same time unless you have an issue where on just keep going bad.