I’m having a problem where, across all filaments and print settings tried, the nozzle is rubbing against the build plate when printing the first layer. It causes ridges in the first layer, and horrible grinding noises when printing the next few layers. It also causes excessive elephant’s foot, and excessively strong bed adhesion with PETG, and continual false “nozzle covered with filament” errors. It coincides with having to generally raise nozzle temperatures 5-10°. All these symptoms started after I disassembled and reassembled the toolhead (without replacing or changing any parts), which seems like a strong hint that the problem is mechanical in nature.
With this information, is there any chance of pinpointing the problem? Like, is there a toolhead reassembly error that would cause the bed levelling to consistently detect too low at every point?
- Printer model used
A1 with 0.4mm stainless nozzle, textured PEI plate for PLA or PETG, blue tape plate for TPU
- Slicer settings used
Many (slicer settings have almost no effect)
- Type of filament used
Bambu PLA Basic, Elegoo PLA Plus, Bambu PETG HF, Elegoo TPU 95A, Siraya Tech TPU 85A
- Photos that clearly show the problem
Typical appearance of 1st layer (Bambu PLA Basic shown)
I am having the same issue. Thanks for bringing it up.
I have a theory, though I can’t prove it: The nozzle has a slight amount of vertical play, and it may get pushed higher in its holder during bed leveling, and then pushed down by extruder pressure early in the bottom layer (maybe at the first deretract?)
I read in another thread here that you can manually slide a piece of paper under the nozzle during bed leveling as a workaround. I wouldn’t consider that a solution, but it’s good enough that I can continue my design work.
I also learned that you’re supposed to periodically take the nozzle off and clean the heating element behind it. My heating element was corroding, which is probably why I’ve had to turn the temps up. I scratched off the corrosion with steel tweezers, which we’ll see whether or not was smart. (At least I know I can replace the whole toolhead if worst comes to worst.)
The heating element and thermistor are located behind the hotend which is in one plastic unit held on by 3 screws. Behind that are some smaller screws. This is a common fault with the A1. You can try tighten the smaller screws as this sometimes resolves the bad first layer issue. I’ve had to replace that whole unit on 2 of my A1’s
Sounds reasonable. I will investigate.
I have not done much PM on this A1 but it looks like I really need to. It has been such a dependable beast that I thought it may go on forever. You know the story, if it ain’t broke, don’t fix it.
Thanks GuyH77 for the advice.
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Totally. Shows how far we’ve come when it’s not every day you have to tinker with a printer
