Printing ASA goes funky halfway through the print

[TheThinkingMan]

A friend purchased some ASA from 3D Radical Prints in Australia. I have been trying to get a consistent good print with it, but part way through printing this object stringing begins.

My thinking is that the stringing is occurring after the support has been printed (at the bottom of that image).

I have been playing around with this for days, and now I am at wits end.

To be honest, I set it up and printed a few parts (well but not great), and then changed settings… duh! I hav tried to start from scratch but I have not been able to get back to where I was at.

Here are the results I am getting so far:

The brand suggests to print between 240-260. I tried at 250 and am now trying at 260. My bed is set to 100c. I have had no issues with bed adhesion.

I have run the Bambu Flow Rate calibration and is has suggested 1.106
I have been printing with all of the fans set to 0.
I have tried to set the retraction length to 1 and 1.2.
I have set the Z Hop Type to Normal too

I am using the 0.2 Strength Profile. The only changes to it are:
Enabled Avoid Crossing Walls with max detour length at 300.
Enabled Supports (set to Normal)
Changed the Top Z distance to 0.275

This seems to be the place where all goes wrong:

The only thing that I have not tried is Drying the filament.

Another factor is that I am printing inside with the aircon blasting all day and night as we are going through a heat wave at the moment.

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Update:
I have since changed the Flow Ratio back to 0.95 and it printed much better.
The stringing occurs still… but not as bad (??)

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Update:
I tried upping the nozzle temp to 260c. I thought that everything was great until stringing occurred a bit later. I have zoomed in on the print out to see some other nasties.

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Update:
I have set the nozzle temp to 240.

The stringing above is typically what it does. Printing the support is fine but when it tries to add part of the model on top it doesn’t stick.
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Update:

I am now changing the retraction length from 2.0 to 1.5 and the retraction speed from 30 to 50

[Neiljt]

Bambu recommend drying with a quality wiki also, images are from the store

Common print quality problems and solutions | Bambu Lab Wiki

[TheThinkingMan]

Yeah… I think that I will try drying the filament tomorrow morning.

Thanks

[lkraus]

@TheThinkingMan

I have been playing around with this for days, and now I am at wits end.

Stop playing around and making random guesses about settings.

Go back to default settings for the printer and Generic ASA. With dry filament, run calibration tests for one parameter at a time. Test for optimum temperature, flow, and pressure advance, selecting the best values from actual samples created on your printer.

Change the grid infill to something that does not cross itself on the same layer.

It takes some time and filament, but less than you’ve already wasted on failed guesses.

[drbboyd]

As a newbie, could you elaborate on the grid infill? I printed ASA a month ago with no problem. Today, I got a huge failure. Luckily, it was a tiny part and not much time or filament loss. The part was stuck to the bed and it started stringing about half way through.

[JonRaymond]

Stringing like that normally happens when the part releases from the bed while printing. You part has a pretty small bed footprint so it could be prone to releasing.

[drbboyd]

Actually, it was stuck good. I had to pop it off.

[JonRaymond]

Perhaps there was an issue with the gcode or a layer shift happened? Have you been able to replicate the issue?

[drbboyd]

After reading I turned off the fans and got this. I guess it was not warm enough in the chamber.
Now, to learn more by reading that entire wiki posted above.
Thanks ya’ll