i am confused. (printer has 2,000 hours on it, my projects do ok). BUT, still confused, as to the PROCESS setting (such as 0.2 standard x1c), versus selecting a filament, and any filament speed overrides.
REASON -
I’m using some TPU 95a, (bambu x1c), and i’ve used one of the downloaded profiles that has everything keyed in, slow speed, etc.
but if i get some of the Bambu 95a HF, and select a standard bambu 0.2 mm layer height PROCESS,and then select the TPU 95A HF bambu filament, does that filament setting have an override,for example, that will slow down my sparse infill (bambu PROCESS has it at 270 mm), to what the tpu 95a HF requires? in the FILAMENT settings, i did not find any item that specifies speed
any help for this confusion is appreciated.
Maximum volumetric speed overrides process speed settings so you don’t get extrusion issues.
As far as I am aware, there are two filament settings that influence print speeds:
- Obviously the maximum flow rate
- And, less obviously, cooling settings: Specifically the command to slow down in case of low layer times which themselfes are set in the max fan threshold
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thanks for replies. still confused, how does “maximum volumetric speed” translate to the “sparse infill speed”?
sorry for my fogginess in this
Go through the course for Bambu Studio and the one for your printer. They’re incredibly well made and it will clear up a lot of your confusion. Sign In | Bambu Lab US
thanbks for reply. i found link, in bambu, and will review them. but, does not seem to have a SPEED turorial, and i did a search of “volumetric speed versus sparse infill” speed. per the AI generated result, you should not set the sparse infill speed above the maximum extrusion speed… that seems obvious, but does not clarify about the actual settings; if i pick a filament that has a low volumetric speed, and i do NOT set the sparse infill speed to something lower, then problems can happen. BUT, how to correlate volumetric speed (example, 3.6 mm/s), to SPARSE INFILL speed (270 mm/sec)?? DO the FILAMENT SETTINGS override the sparse infill, etc, or do i have to manually set them?
I will keep searching, and reveiw the tutorials, …
MVS is the filaments top speed and Process is the hardware speed for the model. Both are used by the slicer to calculate the speed when printing so neither is exceeded.
Change the MVS up or down by 50% slice it and check the speed in the slice results dropdown.
ETA
you won’t see the changes in the process setting but in the gcode
Max volumetric flow acts as a limiter.
If you tell the slicer .20 layer height, .42 line width, and 100mm/s speed, you can math that to find how much material is flowing. If the result would be over the maximum, it drops the speed to comply with your maximum. If you change the shape of what you are extruding (.28 fat layer height for example) and hold speed constant, your flow necessarily increases. There’s more plastic. If it’s over the max, it gets slowed back down again.
Try running a max flow rate test - and kinda eyeball what the printer is doing - to understand what happens when you pass the max
The amount of material the printer needs to lay down is given by the line cross section (line width x layer height) multiplied by the nozzle movement speed. If this value exceeds the safe maximum flow rate, the slicer calculates the lowest safe speed (max flow rate divided by the product of line width and layer height).
Slowing down to give more time time works in a similar way. If the layer time drops below the minimum layer time, then the slicer slows speeds in that layer to achieve the minimum layer time. Although I am not certain, I expect a simple percentage to be calculated and applied to all speeds.
Unfortunately, this can be counterproductive.
In particular for individual, spire like, tall, thin structures. In these cases, keeping the nozzle in the vicinity of the part just injects more heat, leading to the opposite of the desired effect => melted tops.
Fortunately, there are three easy workarounds forcing the nozzle away for part cooling:
- Duplicate the part
- Force a prime tower by taking a smooth timelapse
- Add a primitive cone with a height equal to the part
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Edit: Forgot to add that with sparse infill usually being one of the fastest active printing speeds, it is one of the first to run into the max flow limitation.
There is however a bug that disables this. Or at least that was the case when I looked into layer heights earlier in the year. “Combine infill” unfortunately allows the slicer to use flow rates well above the max flow rate. Prints usually still work. But the infill is rather messy. Orca slicer uses “Combine infill” correctly though.
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to all of you,THANKS VERY MUCH for the detailed answers ! this gives me the info i need to set up the TPU 95a HF, and test it out.
I don’t mind experimenting, and i don’t need it to go super-speed, so i will lower the speeds, but in SELECTING that filament from the pre-defined ones, i know that the maximum flowrate in that definition will keep the project from (hopefully) self-destructing
I currently have generic TPU 95A, and have used one of the frequent user’s bambu profiles, and it works GREAT, it is just slow (understandably), but i get great prints.
but i’d like to experiemnt with the TPU 95A HF (it is currently on sale also), as that can increase the speed of print.
Again, thanks to every one
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