I am normally pretty good and finding answers in previous forum posts but this time I am stumped.
First off; I am getting excellent results with my H2D so I am mostly just looking for understanding. On my previous X1C I was always pretty diligent on calibrating for both Pressure Advance and Flow Ratio on filaments. I tried not to rely on the lidar. Now I understand that with the automatic flow dynamics it should not be necessary to do the Pressure Advance calibration but I could never find if Flow Ratio calibration was necessary or not. I can set a flow ratio for a filament so I thought it should be necessary.
However, I did a test where I used a method where you print a cube in vase mode and measure the wall thickness using a micrometer. You measure all four walls and then average them to see what the flow ratio should be. So, I found a better flow ratio for a particular filament, set the new flow ratio and printed a new cube with auto flow dynamics on. The result was exactly the same as the original cube.
So, does the H2D take flow ratio into account at all with auto flow dynamics on or am I wasting my time?
it doesn’t take it into consideration, but the flowrate usually should be correct at least for bambu filaments.
Wouldn’t it use its own measured Auto Flow Calbration rather than your better value with that option on?
I’d expect Auto Flow Calibration needing to be off to use own values.
At least, that is the case with my X1. Of course, it calibrates differently using the Lidar though.
If you have set a flow rate, make sure to turn flow rate calibration to Off when you send the print to the printer or it will continue to use it’s own value
there’s no flow rate calibration on H2D, what you’re saying is flow dynamics / Pressure Advance.
Flow Dynamics is just the term Bambulab uses for the Flow Rate as you would determine it e.g. in Orca Slicer or according to Ellis Tuning Guide.
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Flow rate is how much you extrude, flow dynamics/PA is how early you start or stop extruding
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Sorry for my mistake.
Even though I use Bambulab printers myself, I am more used to the conventional terms used in the community.
So I would rather say that Flow Dynamics is the term Bambulab uses for Pressure Advance.
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I don’t know why bambu doesn’t call it PA, but it seem like they do have a slightly different algorithm for it.
Well, turns out I simply never realised that there are separate high flow settings in the filament settings.
I ran into an issue where I was seeing nozzle temperatures different from what I had set in the filament profile, then discovering the switch option at the top for the ‘Direct Drive High Flow’ profile. My original experiences with high flow nozzles was an e3d high flow nozzle on the X1C and back then this separate profile did not exist.
After finding that I redid my original test and set a different flow ratio and this time I did get a different result on the print.
So, my conclusion is that you should calibrate for flow ratio, just make sure to set it on the correct profile!