I just set up my H2D tonight. I installed 2x 0.4mm High Flow nozzles, calibrated the printer, and updated the firmware,
I updated Bambu Studio to the latest version a few days ago.
I am trying to do my first print with some Elegoo Rapid PETG Black, I set it up in the AMS the same way as I do for my X1C… Generic PETG.
When I go to calibrate the Flow Rate in Bambu Studio the button is missing, only the Manual button is there. The Auto and Manual buttons are there for Flow Dynamics.
I typically use the Improved Flow ratio Calibration v3 but I can’t use that because it only works in Orca Slicer and Orca Slicer does not support the H2D.
So how do I get Auto Flow Rate Calibration to work until Orca Slicer is updated to support the H2D?
I’ve been using the BBL PETG HF for the Elegoo Rapid PETG and its been pretty good. Definitely close enough to worry about other things.
Until they fix height modifiers to work with the H2D, we really won’t be able to tune them correctly. You can do it one print at a time, but the height modifiers saved a ton of time.
The good news, the error that pops up suggests they missed something. The error thinks the height modifier is a second material for some reason. So, I’m thinking as soon as they get a team to sit down and address it, they will find the error and fix it pretty quick.
Sorry, I did go off on a general tuning tangent with the height modifiers. The flow control isn’t performed the same way it was in the past.
Nozzle pressure sensing and Active Flow Rate Compensation
Smooth surfaces, sharp edges
H2D uses both the sensing capability of its servo motor on the extruder and the high-resolution eddy current sensors on the nozzle to precisely control extrusion by measuring nozzle pressure and calibrating PA parameters for each filament, improving surface smoothness and edge sharpness.
That said, I don’t understand how this is working, but I’m not finding any issues.
I’m a bit confused. I understand that the new printer can automatically calibrate flow dynamics, and I have that option set to auto in my print settings. But I am unclear about how flow rate works in this context.
Does the printer actually calculate and adjust the flow rate automatically during the print? For example, if I manually set the flow rate to 2.00, will it print at exactly 2.00? Or will the printer recognize that it is too high and automatically adjust it to something like 0.98?
Based on the Bambu marketing, it appears to be done at some point doing the print. It isn’t clear to me how an eddy current sensor would measure flow characteristics. It could be sensitive enough to measure under and over extrusion, but that seems like it would be difficult to measure. But I’ve never seen the output from a eddy sensor.
I guess you could test it, but I’d assume it will say with any value you manually put in. Kinda defeats the purpose of allowing modification if you are just going to override it.
The camera on the print head monitors the flow using AI. An NPU is therefore also installed in the device. You can choose automatic / on / off at the start of printing. Ideally, you should choose ‘on’, I cannot recommend automatic, as the values for bambu filaments are not determined via the camera, but via the RFID chip and this does not fit in the end. Just leave it on, print with Generic and you’re good to go. The only thing you then have to do is adjust the temp, which is ultimately a matter of experience as far as manufacturers and filaments are concerned.
and just hope it’s a match, or else we can run the coarse and fine manual flow rate calibration in the Bambu H2D slicer and write that number into our own print profile so that we can use a more accurate number. I don’t see any option for an automatic flow rate anywhere. The only thing that even sounds similar is automatic flow dynamics,
but that’s referring to pressure advance, whereas flow rate is meant to find the goldylocks number that avoids both underextrusion and overextrusion, a completely different thing altogether.
Well, speaking of which, do we get better prints if we set the H2D’s fancy pants automatic flow dynamics to on, or are we better off manually calibrating that ourselves? Which is the better choice? Anyone know? Does it do some kind of real-time pressure measurement and adjust accordingly, or is it just another static measurement done prior to the start of the print, and so possibly no better than what we can do manually?
I submitted a ticket to Bambu support to get some clarification on this topic, and here’s what I learned.
The X1 Carbon has a Lidar sensor, which we already knew, and it is used to automatically calibrate the flow rate for filament. That same Lidar sensor is also used to auto calibrate flow dynamics. It’s important not to confuse the two; flow rate and flow dynamics are different.
The new H2D, however, does not have a Lidar sensor, which means automatic flow rate calibration is not supported. If you want to dial in flow rate, you will need to do it manually.
That said, the H2D does include a built-in pressure sensor that can automatically adjust flow dynamics. I ran the flow dynamics calibration on a new filament this morning, and it worked very well, it was fast and accurate.
My takeaway moving forward is this:
I will manually calibrate the flow rate for each filament.
I will use the H2D to automatically calibrate the flow dynamics and record the K value for each filament.
I will keep auto flow dynamics calibration turned on during printing, just in case the printer needs to make real-time adjustments based on pressure feedback.
This approach seems like the best balance of accuracy and convenience.
The H2D printer uses advanced sensing technology to automatically and intelligently optimize extrusion for each filament. It does this by combining data from a servo motor on the extruder, which can detect the force used to push the filament, and high-resolution eddy current sensors on the nozzle that measure internal nozzle pressure in real time.
This allows the printer to accurately determine how the filament flows and automatically calibrate Pressure Advance settings to match the specific characteristics of the material being used. As a result, prints come out with improved surface smoothness and sharper edge definition.
This calibration process happens smartly at the beginning of a print, but only when needed. If the same filament has already been used in a previous print, and the printer has stored its calibration data, it will skip recalibration to save time. This ensures consistent high-quality results without the need for manual flow rate tuning, while avoiding unnecessary repeat calibrations.
it sounds as though some people who depend on top-notch print quality may want to run a confirmation test print before starting their multi-hour/day high stakes print.
Does it happen only at that time, or, in addition to that, is there also some kind of real-time monitoring and adjustment over the course of the print, as implied by:
There will almost always be some level of jitter, but it’s also important to keep in mind that even manual calibration can drift over time.
For example, if the filament was calibrated before drying, and then dried and printed afterward, the results may differ slightly. Variations can also occur between different colors or filament batches.
Several factors can influence calibration and print results, so having an automated algorithm run before each print can help maintain consistency and get results much closer to the ideal.
At this time, the printer does not change values on the fly, during printing. It uses the calibrated values from the beginning of the print. When set to Auto, it will smartly use the process explained in the previous post.
There still seems to be some confusion between flow dynamics and flow rate. What you’re describing with the new pressure sensor in the H2D relates specifically to flow dynamics. In Bambu Studio, when I start a print with the H2D, I do see an option to automatically calibrate flow dynamics but there is no option to automatically calibrate flow rate.
On my X1C, I have the ability to automatically calibrate both flow rate and flow dynamics at the start of a print. The calibration menu on the X1C also includes dedicated options for both. In contrast, the H2D only supports automatic calibration for flow dynamics, there is no equivalent feature for flow rate.
I tried manually calibrating a filament using Bambu Studio on my H2D, and I noticed that a few of the flow rate squares were noticeably over-extruded. That aligns with my understanding and personal experience, although I’ve only had the printer for about a week.
Can you please clarify your explanation between flow dynamics and flow rate? They are two distinct concepts, and it’s important we’re not conflating the two.
My apologies—somehow I mistakenly thought that both flow dynamics and flow rate could be automatically calibrated at the start of every print. I was wrong. You can automatically calibrate flow dynamics at the beginning of each print, but flow rate needs to be calibrated manually through the calibration menu.
Not quite. X1C does also offer an automatic flow rate calibration:
just not one that can be set to run prior to every print, like you can with automatic dynamic flow calibration. I presume the reason is that it consumes too much build plate real estate, and so it would cramp the size of what you could print by probably a lot.
