When to use Flow Dynamics Calibration Option when Printing?

I’m confused about the Update Flow Calibration option when sending a print to the printer. When do I want to use it? I’m uncertain when it is best to check this and when it is best not to check it. I do change to different filaments a lot, so I have resorted to always checking it, but I am not certain if this is necessary or not.


Screenshot 2024-02-10 at 15.26.44

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Check it anytime you change filament. You’ll get the best results that way.

If you prefer not to calibrate every time, use the calibration tool in Bambu Studio (not Bambu Handy) and create PA Profiles anytime that you have a new roll. You’ll be able to select the profile the next time you print with that filament.

So, to keep things simple and maximize, prank quality, just check it every time?

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Yes, if you’d like to set it once and never think of it again :smiley:

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i put off all of them most of the time

So under what conditions does it “remember”? And will it trigger doing flow compensation when it “needs” to, such as when something changed?

Is it keyed to a manufacturer or type or what? I understand the general concept, but what are the specifics?

I’m happy with the prints but want the best possible quality and don’t mind an extra minute on a 4~6 hour print.

The automatic calibration may show slight deviations in the calibration result. This is therefore not the most optimal method. If you really want the best results, then dry the filament, calibrate it manually and save the result in a profile that you can use again later. Just make sure that the filament is just as dry the next time you use it as it was when you calibrated it.

How is this done? is there a step-by-step available? (Especially: what is meant by “calibrate it manually”.)

PS: My filaments are always dried to <20% and usually to 10% RH.

Follow the calibration instructions that @KanneKaffe provided. Choose the manual option.

How it’s saved after that can be confusing. The first calibration value, flow dynamics aka k-value, is saved in what’s called a PA value (aka Pressure Advance). This remains active as long as the printer is on. If you turn the printer off again, you will need to re-select it on the Device tab. The second calibration value, flow rate, will be saved as a filament profile. The two values aren’t tied to the same filament in that you have to select the filament in the filament list on the Prepare tab AND you have to select the PA Profile on the Device tab.


I wrote a mini guide for a separate problem called “chattering.” At the bottom is an in-depth description of how k-values are stored. If you want to not have to remember to re-select the PA Profile anytime you shut off the printer, I suggest giving it a read as I also take a deeper dive into OrcaSlicer. It’s a fork of Studio and has a superior (in my opinion) method to manage filament values.


No. It’s all done manually. Ideally, you should calibrate every new roll of filament, even if it’s the same colour from the same manufacturer. As long as you saved the profile, you shouldn’t need to recalibrate that roll until you’ve run it out.

There are exceptions where you might need to recalibrate an exisiting profile for a roll.

  • If you replace the nozzle
  • If you change the filament’s printing temperator or the max volumetric speed
  • If you dry the filament after you’ve greated the profile
  • Whenever you notice issues that can’t be explained by any other means other than maybe the calibration is off (can happen, especially when choosing values manually).

If you haven’t done the manual calibration, leave it checked. If you have done the manual calibration and have the k value set in the filament menu, you can uncheck it.


Indeed it is. Beyond the average user.

Thank you very much for the excellent explanation. This is very helpful!

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Thank you for that excellent link! It cleared up my mis-understanding about Studio’s use of a PA value set in OrcaSlicer.

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No problem! If you have any other questions or if I can help explain it in another way, please feel free to ask.

I usually just leave it on. I change filament so much.

It wont hurt anything, just takes longer to get printing
I usually look at quality not quantity. Ya some prints take along time but if it turns out well the. The time was worth it. Less rework or reprint (if any)