H2D Purge volumes - AMS

[neofa]

Hi,

I’ve been doing some testing when purging filament through the same nozzle (right one)
It seems that even with the Flushing Volumes set to 0, the printer still flushes filament.

As you can see, Bambu Studio gives me the expected amount of filament usage (which is 0g purged) but when printing the H2D ignores it and purges like the puge multiplier is set to 1.

Even if i adjust the multiplier to .1 or .2, it will still fully purge, ignoring the purge values.

Here is an example with .4

Analysing the Gcode, shows less purging, though the “VG1 E” command seems to be commented.
I’m not fully understanding the gcode here, on the left is the “0 purge” and right “0.4 purge multiplier”

i’ve checked the experimental settings to retract before cut in bambu studio

which is probably liked to this “M620.11 S1 L0 I3 R10 D8 E-18 F523.843” which seems normal.

Did anyone try to change the purge volume and did it work when printing ?

This is obviously a test to isolate the issue, i’ve noticed this when printing other multicolor models.

I’m probably missing something here if anyone has a suggestion

[Diaghilev]

I’m also having a lot of problems with the right nozzle pushing WAY too much filament, even with my flushing volume turned way down. Very curious to see any thoughts or solutions on this one.

[Leonilian]

Is this with a 0.2mm nozzle? There’s a known issue currently where the 0.2mm nozzle will purge more than it should

[Diaghilev]

I had no idea, dang. Can you link me, please?

[Leonilian]

Here’s a few threads about it. My theory is that it’s purging 0.4mm amounts but it’s just a guess

H2D and the 0.2 Nozzle

Hi there, there are some Threads about the 0.2 Blob issue on Reddit but i canot find anything here. Since it should be a Firmware/Slicer issue. has anyone found a workaround for those ? Problem is the H2D creates huge Blobs while Flushing so it is just a matter of time till the Rubber gets flushed with it if u dont Babysit. [blob2]

https://www.reddit.com/r/BambuLab/comments/1ka2nq9/purge_with_02mm_nozzle_on_h2d/

https://www.reddit.com/r/BambuLab/comments/1jwwuqt/purge_issues_with_h2d_02mm_nozzle/

[3DTech]

I’m hoping the new beta firmware will help fix the over-purging problem.
Lets hope this is the fix:
6. Optimized the purging strategy

[neofa]

I’ve opened a ticket to bambu support.
First guess on their side is that it might be a firmware bug as the printer does not care what purge multiplier is set.

I’m using a 0.4 nozzle, didn’t run any tests with other sizes

[neofa]

This looks kinda interesting !

Will give it a try and do some testing on my side.
Thanks you

[user_2499955747]

sadly it did not hope it will be fixed
in the Future

[neofa]

They’ve replied to my ticket confirming it is a bug.
It will be fixed in a future firmware update …

Let’s see then