Hello I am experiencing loud knocking during rapid z movements on my H2D running fimrware 01.04.00.00. See this video for the sounds: https://youtu.be/E-H29B51sws When trying to locate the origin of the sound it is noticeably louder when placing my ear near the bottom of the H2D, especially around …

Welcome to the forum. Have you looked under the printer to see if anything is caught in the Z axis belt/pulleys? [0011]

It sounds a pulley isn’t tight on it’s shaft, allowing the shaft to rotate a bit before it finally “hits” the set screw. The other possibility that comes to mind is one of the leadscrew bearings isn’t being retained and is actually being pulled back and forth when the screw tries to turn. I agree …

welcome to the club : pretty sure this it that. [image] Loud knocking during printing. Suspected Z axis but dunno anymore Bambu Lab H2 Series Hello, I am having a super wierd loud knocking during printing When I started noticing it it seems like it was happ…

Bambu has promissed me that the next firmware will fix this. Great progress so far eh ? P.S. to rule out any mechanical faults, roll back the firmware to something from early 2026 (I have H2C so different schedule). In my case. rolling back to one before the last (which came out in June and introdu…

I am now experiencing the same knocking sounds with the new firmware during Z-axis hops, will this cause extra wear on the lead screw nuts?

Hi, First and foremost, “welcome to the club.” Sorry, couldn’t help myself. I am so disgruntled with Bambu about this that I get bitter whenever I think or talk about it. Please read through my forum thread that I linked earlier. It starts off a bit clueless, as the investigation and back-and-fort…

I’ll finish my current print and then revert to the previous firmware version. I’ll let you know if the noise is gone then. Update: It will take a while to get the results of the downgrade; coincidentally, the right hotend heater stopped working after the downgrade, so I have to wait for spare part…

My H2C does make the same noise. Well, sometimes not for every print. Seems to be more often when chamber temperature is high (60deg).

Mine as well, I was printing some PET-CF last night and noticed it. Likely the accel/decel curves are just a bit too steep.

thank you !!! i was starting to get worried about this new strange noise also :thinking: you save me hours trying to find if i have an unscrewed bolt :sweat_smile::sweat_smile::sweat_smile:

H2D rapid Z movement Knocking on 01.04.00.00

Bambu Lab H2 Series

Suchy_101 August 28, 2026, 2:56pm 4

welcome to the club :

pretty sure this it that.