I have found a room for improvement with the Bambu Lab printers using AMS.
When i want to print with AMS and use PETG and PVA as filaments, i always run into problems.
When the X1C uses AMS to change filament, it always bring the temp to 250 degrees to load new filament and to purge filaments.
This is a big problem for filaments like PVA which crystalizes at temps above 240 degrees, or even lower.
What I found happens is that it starts printing with PETG fine, then it comes to the section where it prints PVA, and it loads PVA in with 250 deg celcius temp, which causes partially crystalization.
This can either result in problematic print with PVA even if the temp is lowered after since the crystalized parts clog the nozzle, or when you afterwards bring in PETG again, it brings the heat into 250 to unload PVA and reload with PETG …again causing more crystalization.
I have tried to dry both my PETG and my PVA up to 24 hours, and it makes no difference because the X1C loads, purges and unloads at 250 degress, it always cause PVA to clog the nozzle.
Strangely, when i print with a filament like PLA, which prints at the same temps as PVA, the problem is less happening. Eventually it happens but not so much.
So i would really like to see a feature that let us adjust the load,unload and purge temps of filaments to make it easier to use PVA without risk of clogging.
Having the ability to make profiles on the printer with filament combinations, or to just be able to set the load/unload/purge temp to a max manually would be great.
Have you set the max temp for the PVA in the filament profile settings? Are you using Bambu PVA or 3rd party stuff?
I’ve only had experience with PLA + PVA (both Bambu) and haven’t had any clogs. Main issues I get is a lot of stringing with the PVA. You basically have to dry it out before every use as even leaving it sealed in the AMS for 2 or 3 days will cause it to start stringing again.
mine is set to 200. The actual printing temp is not the problem, the problem is the filament change temp which Bambu has locked to 250 degrees for all types of filaments. This causes PVA to crystalize and clog the nozzle
Not using Bambu PVA but other recommended brand of high quality.
Basically I want Bambu to include , in their generic filament profiles, an option to lower the filament change temp to a custom value, that way I can set the actual loading temp of PVA to maybe around 230 which is max temp for this PVA.
What PVA are you using because honestly my Bambu stuff was only good for the first print, now it is awful. I’ve tried drying it twice, tried lowering temps, nothing seems to work. I think the issue could be the same one you are facing, it’s crystalizing on filament swap and then clumping up when it starts to print. This seems a very basic oversight to me. When I use my eSUN PVA with my Creator Pro 2, it will start smoking at anything above 180c so I can tell how sensitive this material is. Honestly feel like I’ve just wasted money on this Bambu PVA and it’s holding me back on a product im making.
Well dang. I got a spool of PVA to try some close support printing but am wary of even unbagging it with these discussions. It would be nice if the software was smarter about flushing the extruder with temperatures more appropriate for the materials being swapped.
They do, for example the thread for “petg-hf sucks” (not sure what the exact title was) where a user received a very wet roll of filament. You sometimes find the bambu support responding to posts as well.
I do not want to fiddle with gcode to control this. I just want a menu standard on generic filaments on the printer itself, so that when i make a filament profile, i can select the change temp to prevent crystalization.
I am also getting oozing and stringing with the PVA. Even after 10 hours drying - when it goes over to the filament cutter a string oozes out that then drags across and catches on the print and tears off. Leaving it either stuck in the next print path or sticking out like a little hook to catch the next strand. For how much they charge us for this filament this is absurd.
