Pressure Advance/Flow Dynamics

[wdboyd]

Hey Everyone.

I’m playing around with flow ratio and preasure advance calibrations and I need to ask for some advice.

For flow ratio, I’ve been using hollow boxes so I can measure wall thickness with a micrometer and compare to my ordered wall thickness to calculate the actual flow ratio. (I trust results that I can measure better than my eyes or fingers and it’s worked well for me.) I always start with the ratio set at 1 and calculate from there. I figure a 1:1 ratio is “ideal” so that’s probably the best spot to start from.

For PA i tend to prefer the pattern over the straight lines, but what is "ideal’? Is it a PA of 0? Just curious as to what setting I should set the filament too for the first pass and what line I would use to verify that the changes I’ve made yeild the correct results on a follow-up print.

Thanks in advance.

[Lenyo]

Good question: do the built in calibration tools baseline from the current setting or some default value? I’m not sure. I know right around 0.02 is the PA I end up with for most filaments that I have calibrated though, but I started from the default so I would just go for that with the corners test.

[lkraus]

Line test picture from the wiki: Flow Dynamics Calibration | Bambu Lab Wiki

Pick the line with the most uniform width.

For the pattern test(Pattern Method | Ellis’ Print Tuning Guide), pick the value with the sharpest corner and no gaps.

The currently saved PA value has no effect on the test. The test prints each line with a different value. “Ideal” is whatever value produces the best result for that particular filament.