A1 weird extrusion problem with some models

[gboy]

I’ve troubleshooting this issue for few days and I’ve spend many hours on it. I appreciate your help and input.

I remixed a model (here’s the link to download it) and wanted to print it on my A1. It printed half the first layer and stopped extruding.

I tried again and again and started noticing that the extruder gear was clicking intermittently shortly after the print starts. Then it reaches a point (see below) that appears to be consistent among all the prints that I tried, where the gears start clicking non stop and the print fails.

That’s when the troubleshooting rabbit hole started.

• I heated and cleaned the nozzle with the stock needle multiple times. Removed/checked the AMS hub. Disassembled the toolhead and cleaned the gears twice. Tightened the 4 screws on the back of the plate behind the nozzle. Replaced the ptfe tubes with ones that have larger diameter from the inside.

Then I thought it might be the filament (it’s Elegoo PLA plus - set as Generic PLA in Bambu Slicer). I tried a different brand and the same issue happened.

Then I thought maybe the nozzle has residue on the walls and it’s not being cleaned well. Few weeks ago I printed TPU and PLA-CF (didn’t know it’s CF) had extrusion issues, so I thought maybe that’s the cause. So I replaced the 0.4 stainless steel nozzle with a 0.6 hardened steel and the same issue happened.

Note that I was printing gridfinity bins and face a similar issue few days ago. It seems to reach a certain point in the print and it stops extruding. So I’m not sure. Why does the same PLA filament work fine on some models and causes issues on others? Could this be a sign that the extruder gear is failing? If that’s the case, shouldn’t prints fail every time?

Could it be the model itself?

[lion7718]

Not saying this is your issue, but read this.

A1 Mini & A1 Users: Solved: Screw fell out of toolhead

I’ve seen a few posts here & doing a Google search over the weekend after it happened to me. I noticed my first layer was bad, tramming the bed didn’t fix it. I changed the Z-Offset in Bambu Studio, it worked for a few prints. The Z -Offset would change during the print. The last print I started having extrusion issues. During a calibration a screw fell out of the toolhead. I took the toolhead apart & couldn’t find where the screw came from, I was at a lost & put in a support ticket. Support…

[gboy]

Yeah actually that was one of the articles I came by during my googling. I mentioned above that I tightened the screws on the back of the block behind the nozzle. Mine were not loose anyways.

I’m hoping someone would test the model on their A1 & tell the results.

Here’s an update for future readers:
I believe the issue was caused by the model itself. This is the first time I come by such an issue. The model was remixed on tinkercad and it might be the reason behind the print failures.

I ended up NOT changing the gears, and when I tried printing other models using the same filaments, everything seems fine. I did however replace the nozzle to a hardened steel one since I already bought it thinking that it’s the source of the issue. But I don’t think it is.