Volumetric extrusion vs. Standard extrusion



  • I've been wondering what is the better for a long time?

    About my story:
    At the beginning I printed with my UM2 with volumetric extrusion and found it nice. Due to the conversion to dual, the "UltiGCode" volumetric printing was more complicated because Cura had some restrictions (Ultimaker 2 printer profile).
    In a one-to-one comparison, I found the expressions with volumetric extrusion ever better (optically).

    Now I've been on Duet for some time and today I'm wondering whether volumetric extrusion brings more advantages than I know.

    Of so many reading, I am already quite confused.

    I would be happy to hear from you about your answers.



  • I personally can't think of a single reason to use volumetric extrusion, except in the case that you want to be able to precisely input the filament diameter mid-print and achieve "optimal" extrusion based on that number.

    But, in practice, doing that is basically not effective at all, or as effective as just guessing and dialing down the flow rate.

    Along similar lines, it is in theory possible to put a filament diameter sensor inline, providing real-time feedback about filament diameter, but that's also hard to implement effectively.

    I would love to know if anybody has any other reason to use Volumetric extrusion.



  • @bot Prior to switching to Duet, I used volumetric extrusion all the time. I would measure filament diameter at 30 points over about 5-6 m of filament on every new spool and mark it with the average diameter. It was a good way to get consistent print quality because filament manufacturers were supplying filament that was supposed to be 1.75 mm, but often wasn't. I gave up on it a couple years ago when I found the filament makers, even the low priced Chinese companies, were doing a much better job of providing accurate 1.75 mm diameter filament. That was coincidentally about the time I switched to Duet and using volumetric extrusion was a little difficult with RRF.



  • Using volume to describe an amount of material feels natural. That the printer doesn't currently care and has to convert this value back is a technical detail not worth noting. If I use post-processing scripts, then it's easier to work with volume.

    All just preference, I guess.



  • @Edgars-Batna said in Volumetric extrusion vs. Standard extrusion:

    Using volume to describe an amount of material feels natural. That the printer doesn't currently care and has to convert this value back is a technical detail not worth noting. If I use post-processing scripts, then it's easier to work with volume.

    All just preference, I guess.

    Interesting point. I don't myself find volumetric values more intuitive than their linear counterparts. I find neither intuitive, really. Also, I am not usually commanding E moves myself. But, yeah, if you are doing some kind of testing or specialty method of printing, I can see why having volumetric amounts could be more useful.

    In what cases do you use these volumetric amounts, Edgars?



  • @bot said in Volumetric extrusion vs. Standard extrusion:

    In what cases do you use these volumetric amounts, Edgars?

    It's easier to get to volumetric rate. I did a few scripts over time to test stuff and I usually let it output various information related to extrusion without having to specify extra parameters. But, all in all, it really doesn't matter that much.

    The Chinese used to ship crappy filaments, so I used to change diameter in the firmware. The last few batches have been spot on 1.75, though.



  • Ok, thanks for your answers.

    You made it easy for me, I will stick to standard extrusion.



  • Rather than start a new thread, I thought I would just try to build on this one. I'm also interested in converting to the use of volumetric extrusion. This would allow me to lock in some "standard" gcode (e.g., calibration prints), move filament-specific gcode into filament configuration, etc. I like the concept.

    My question is really this, though: Does someone have a document describing how they've made this transition, how they are using the Duet filament capabilities in conjunction, etc.? My searches are not turning up something helpful.

    I could just futz around and eventually figure this out, but I'd rather build off someone else's success.

    Thanks!


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