It doesn’t run “forever” on my A1 mini. It does run for a long time though. As best I can tell, this is actually normal and expected behaviour and does seem to end up with valid flow dynamics calculation. I certainly would agree though that it’s weird and probably needs some form of addressing.
My guess is that the changes in pressure are more subtle and take a lot longer to ascertain with a 0.2mm nozzle. I also guess that once the blob gets so large, then surely it would begin to mess with the measurements. On the other hand, this may be intentional as a way to approximate the back pressure presented by the print bed or previous layers during prints. It would take longer for a 0.2mm to squirt enough filament out to create such a blob for back pressure measurements, if such is in fact the intention for the process.
In the meantime just don’t turn on Flow dynamics for the 0.2mm nozzle — or let it complete just once, as I did. Run manual calibration instead.
Oh and yeah … the first couple times I tried this, I turned the printer off, thinking something just HAD to be wrong. A perfectly reasonable response I feel.
I had the same issue (0.2 Nozzle, PLA), disabled “Tangle detection” in the Print Options (In the Device Tab) as well as “Flow Calibration” when uploading the sliced model (Next to bed levelling) and it ran smooth after.
I let it run and indeed it ended, but it clogged the nozzle for about half of the first layer… Could be the filament of course, but it works fine with a 0.4mm nozzle.
I’ve just unboxed an A1 mini and have this issue with the 0.2mm nozzle on the latest firmware. Below are my observations:
On the latest firmware (01.03.01.00), 0.2mm nozzle causes the calibration to run forever on the third sequence (after 2 purge blob ejections), eventually leading the nozzle to get drowned in plastic.
This issue does not affect the 0.4mm nozzle, though factory reset does not fix the issue for 0.2mm nozzle.
Reverting back to the factory firmware for this machine (01.02.02.00), the issue seemingly disappears: On the third calibration sequence (after 2 purge blob ejections), the calibration concludes and the print begins.
I also have a full sized A1, on the latest firmware (01.03.01.00), and this issue is not present. I can print with the 0.2mm nozzle without problems.
So far this looks to me like a firmware issue, not something wrong with the hardware, so
If anyone from bambulab can chime in on the issue and put it on the list of things to be fixed in the next update it would be fantastic.
Unpacked my mini today. It updated to 01.03 immediately. First print with 0.4mm nozzle, the flow calibration went fine. A small blob, as intended. Since the second print, still on the 0.4mm nozzle I now get massive blobs even blocking the shoot, if I don’t remove them in time it would probably glue the nozzle into the box.
blobs will occur during PA calibration on A series printers. that`s quite common, and since the pressure in 0.2mm nozzle can hardly converge, PA calibration can sometimes fail , or give out divergent results.
this issue went away after downgrading 2 steps on the firmware… I will wait for further devs on this area, seems like the latest firmwares are very buggy. Noticed a lot of defects on my prints too, including excessive elephant foot and else…
The latest bambu studio update has seemingly fixed the problem for my A1 mini with the latest firmware, in the change notes it states a bug was fixed that causes the 0.2mm nozzle to take too long to calibrate the extrusion.
Our A1 Mini does also have this issue since today.
We never changed the nozzle, still the 0.4mm nozzle from factory is installed.
The firmware was 01.03.00 when today the flow dynamic calibration kept going without stopping.
We tried different filaments (PLA Basic, PLA Matte, different colours) and also updated the firmware to 01.03.01, but this issue still persists.
Also after several power cycles and complete printer calibrations.
Currently the workaround is to deactivate the flow dynamic calibration, but we would be happy if Bambu Lab could fix this bug soon.
I’ve came across a similar issue on one of my A1 minis (with it’s original 0.4mm nozzle) running the 01.03.01 firmware where it was taking at least five minutes to run flow calibration (I only do this when I swap between the two types of 3DQF’s PLA’s I use).
However, I’ve just upgraded to the 01.03.02 version (literally 10 minutes ago) and now the calibration appears to take around 90 seconds.
Weirdly my other A1 mini with it’s 0.6mm nozzle didn’t have the same issues when on the 01.03.01 firmware.
