How to set the speed for a given filament?

No here is a Carbon Fiber Motorcycle Throttle grip just off the X1C its flawless. Now this is Sainsmart ePA-CF. I have also printed PET-CF and it should not have artifacts.


Here is a PETG-CF Superman that i printed a while back.

This is what I get when I print with anything other than PLA. The bottom one is Bambu PETG, the black one PET-CF and the purple PETG-CF. All using the stock profile.

Had the printer two weeks. Had a Prusa for 3 years and an ender before that. So not that new to printing. However, never had to tweek until now.

What masc2279 is telling you is correct information.

The calculator is just a tool for reference only of the volumetric speed settings of how you can affect them when you want to lower the volumetric setting.

What Bambu lab has done is given you a process with manual speed settings and they just change the max volumetric flow rate for the filament being used to cap the max print speed for that filament type.

If you lower the Max volumetric speed you can slow all the speeds down just look in your preview menu for speeds and you will see the changes happen.

The more advanced users like to also manually set all the speeds for the filament and part design and then cap the volumetric speed for the hot end max flow rate.

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The only time i see that type of mess from prints is when printing too fast, temp too low, Layer to dense for the filament where it scrapes off the last layer or Filament is bad (Wet or old)

Or a combination of the above.

But without seeing all your settings a single top layer can cause those issues on the top two … there are so many things that can be causing your issues.

Reset everything to stock dont change any settings for everything the filament and the print settings unless you are slowing the print speed or adding more top layers, bottom layers, or walls and re print.

Some things you can change:
Don’t use grid infill, especially for CF, as the nozzle will run over the previously laid filament in the same layer which causes pieces to lift up and put blobs everywhere. This is what’s happened in your bottom picture.
You need to use more top and bottom layers and a greater infill if you have a large surface (infill is a percentage of the model’s size), as the stock settings I believe are only 3 top and bottom for 0.2 layers. This is what’s happened with your PET-CF print where you can see the infill is protruding through to the top layer.

What slicer are you using Orca or Studio ?

I’m not at my office and I use Orca slicer so I downloaded studio on my laptop for now and I’m going to do some basic petg speed settings to get you started.

Ocra slicer has more settings and calibration tools.

Do the flow dynamics calibration and the flow ratio should be around 0.95 to 0.98 range

Studio Slicer PETG settings just test on basic petg for now.
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You also want a Z offsets with these filaments

Multi Z Offset Settings

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Hi
Thanks for those settings. I am using the Bambu slicer but did try the Orca one. Made no difference.
However, I decided to start from scratch here, and bought some fresh PETG filament from Sunlu. I also bought a Inovation food dehydrator and just dried it at 65C for 16 hours. I am now trying a print and so far it looks promising.
Next I will do the Calibration in Orca and see the final results. I will report back.
Thanks, All!

Did the calibration in Orca. Flow ratio was dead on, pressure advance went from 0.2 to 0.28
Volumetric flow was much higher at 16. I left it at 12.
The print with Sunlu PETG is essentially perfect. Some issues with bridging on bridging tests but to be expected.
So, that’s Perfect PLA, Perfect PLA-CF (with 0.4mm nozzle) and for the others I am waiting on a 0.6mm nozzle. But I suspect they will be great since with the 0.4 the only defect was upper layers that showed the infill. This is fixable.
I will keep everyone posted on the final outcomes in a week or so. (Even a snail is faster than our snail mail.).

Cool now you have a good working baseline petg profile to work with :grinning:

PETG will flow more as you found out but you have to also increase the nozzle temp to get the layers to bond well and not all parts sizes will like the higher temps.

Also with any carbon fibers filaments you do not want to go below 0.15 layer height and that also depends on the type or size of the fibers in the filament so if you do not know use the .20 layer height or more to be safe also with carbon fiber you can not print as fast as basic petg so your petg-cf volumetric speed will be around 9 range with .4 nozzle @ 100 mm/s with the .6 nozzle the speed will be 72 mm/s.

I print with both nozzle sizes but you have to know the carbon fiber filament specs.

Happy Printing :v:

I don’t understand the concept of changing the speed instead of changing the max volumetric flow!

Hello Ricaxe,

You can lower the max volumetric speed setting to cap the max print speed allowed or you can do a max flow rate test and cap the max flow rate the hot end can extruder filament before it fails so when Bambu lab tested the basic pla the max flow rate was 21 mm/s.

So the Bambu lab basic pla max volumetric speed was 21 mm/s and if the layer height is at 0.16 and the sparse line width setting is at 0.45 the max volumetric print speed is 292 mm/s and the Bambu lab speed spares infill setting in the process tab is at 330 mm/s but we already know it will not reach that speed because the max volumetric speed is 292 mm/s

But what if you only wanted the top surface layer to print at 100 mm/s max speed then you can manually set that speed in the process speed tab and the part has to be big enough to also reach the top surface max speed.

So we have all these manual max speed process settings in Bambu lab slicer and the spares infill is at 330 mm/s but what if we have a filament that will not like high speed printing and it has to run around 80 mm/s speed then we can set the max volumetric speed to a lower setting of 6 with the above settings and it will not print above 83 mm/s

The other option is you would set the max layer speed in the process speed settings tab to 80 mm/s but you would also find out the outer wall might look better at 50 mm/s these are just ways you can tweak speed settings.

I hope this helps you out :slight_smile:

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I know the answer but I prefer to cap on max volumetric speed!

May I request your advice on settings for PA-CF like you did with the PETG? Your PETG settings were so good that I want to experience it with PA-CF. I’m using Polymaker PolyMide PA6-CF if you need that information.

I am using a .6mm nozzle and have just completed the automatic calibrations in Bambu Studio.

Other than the layer height and line width settings, would it mostly be a copy of the PETG settings for the speeds?