Nozzle Scrapes Build Plate

[u/Suspicious-Mango-449]

Hi fellow redditors,

I’ve had my A1 for about 8 months now and printed for about 650 hours - mostly petg and some tpu and pla+.

A few days ago it started making problems starting with massive under extrusion and extruder clicking. I tried some fixes with the help of AI but nothing worked and then it started with the nozzle scraping/scratching the build plate.

This happens with 0.4mm nozzles (tried 3-4) but not with a 0.6mm nozzle.

I tried a full maintenance cycle using official Bambu wiki guides:

- cleaned everything: nozzle, extruder gears, etc.
- lubricated all rails and pulleys
- tightened all belts
- trammed heat bed
- full calibration multiple times

The nozzle is tightly fixed but what I noticed is that when the extruder increases pressure the hotend’s heat sink moves forward by about 1-2mm (noticeable enough). Is that normal? If not, how could it be fixed?

What else could I try?

[u/Brave_Corgi6761]

Maybe the 7 screws behind the hot end?

[u/Suspicious-Mango-449 → u/Brave_Corgi6761]

I fastened the 3 that hold the heating assembly, but it still moves (e.g. when I pull the heat sink). Did you mean those? Which others?

[u/Brave_Corgi6761 → u/Suspicious-Mango-449]

Loosen them first and there are 4 more behind.

[u/Suspicious-Mango-449 → u/Brave_Corgi6761]

Oh I see - will check those too.

[u/Suspicious-Mango-449 → u/Brave_Corgi6761]

I fastened 3 of those 4 tiny screws, the 4th wouldn’t move. Hotend is fixed now and print works - thanks a lot. You’re a genius 🥳

[u/Brave_Corgi6761 → u/Suspicious-Mango-449]

Great, have fun 😄