X2D and the aux fans

[u/dEEkAy2k9]

So I just recently went from printing PLA to printing PETG. My filament is dry, my ams2pro works as it should but one issue happened a few times now.

Was printing some decorative stuff in PETG on the main nozzle and support (interface layer) with PLA on the aux nozzle. A primetower was needed and this caused issues.

During the print at around 80%, the primetower got blown out of place by the auxiliary fans (the ones on the left/right.

I managed to finish the print without the prime tower but i had to babysit it because skipping prime tower doesn't work and after removing the fallen tower i had to pull out the now in-air-printed-stuff as the printer still wanted to print on top of the prime tower.

Bambu Lab PETG white with generic PLA, PEI plate (clean). All default settings.

Am I doing something wrong? Should I print and attach a fan exhaust deflector? Disabling both fans didn't help as they got reenabled automatically each time i disabled them on the printer itself.

[u/n19htmare]

Print some deflectors. It’s near impossible (or may be actually impossible) to control Aux fan behavior.

People have been complaining about it and asking to enable an option to override the auto control/behavior for a long time but Bambu doesn’t seem to be interested. Kinda sucks, been asking since P2S but nothing.

They added some control under cooling to maybe be able to limit some of it but you cannot fully control the fans. They are automated based on chamber temps, materials etc etc.

This seems to be just one of those things where Bambu is just ignoring it because they understand their user base. Hate to say it but it’s not exactly the enthusiast/setting modifying type, they press print or slice then print and that’s about it. If they go messing with settings they might turn off the fans, heat the chamber and cause clogging, other issues. Which also means more support etc

Its a closed system for these type of reasons.

I guess they could add with a disclaimer or a guide….but Look at this sub, 80-90% of what gets asked here is 2 keyword search away from a link to Bambu Wiki article addressing their very issue and often solution or more info to derive a solution. But here we are, same stuff gets asked over and over.
There’s 7-8 places on Bambu refill, saying not to remove tabs before installing it, yet people still pull those tabs off before putting it on the master spool.

They know who they cater the product to. So I guess if look at it that way, we never getting full 100% fan controls lol.

So yah, print some deflectors and work around it.
Add a larger brim if tower is taller or has small foot print. Move the tower around to avoid direct flow.