Maybe I just need more sleep, but at the moment I can’t quite wrap my head around that. I can see that you are arguing for some kind of theoretical upper-bound, but how would that number be either measured or calculated? Is there at least a commonly used technical term to refer to such a number?
I may need to circle back and take another pass at your answer later on with a fresh mind. I’m afraid I’m not doing it the justice it may deserve. Thank you for sticking to your guns and being persistent if you believe the ABS hypothesis is in error.
I am not arguing for it (in the conversational sense or the angry sense), it is what is says it is.
Maximum in this sense equals your phrase “upper-limit”.
Yes.
It isn’t that I believe it is in error, they state it as their testing methodology, nothing more.
Making the leap that the column called “Maximum Volumetric Speed” should be renamed as “ABS” (or similar) because they selected that material rather than any other is a leap too far.
They specified a number of other column headings showing those material values, if it was meant to be ABS, they could have written that.
But, that is conflating a term that has a meaning with a testing paradigm.
Given you no longer appear to want to know what the term means, what benefit do you speak of knowing an abstract number?
Materials have a MVS, hot ends have a MVS, the printer has a MVS, the slicer has a MVS setting.
For the slicer it is a cap by which things will not be allowed go through faster no matter what other speed values you give.
For the hot end, filament and printer it is a value determined by those who manufactured each that says, more than this is dangerous, dumb, damaging (depending on your perspective).
If you want a higher value as you believe you can get things to flow faster you can guess or use the provided values by those who tested things.
The chart you first linked shows that the materials all have MVS lower than the maximum. This means for the average user, using standard filaments, they are pushed through at a lower MVS than the nozzles in question could accept, because those filaments can’t be pushed faster according to the manufacturer.
Its main purpose was to provide a side by side comparison between a standard nozzle and the high flow one. Little else.
Number one is literally a max volumetric speed test. They say they used ABS, like almost every other manufacturer does for these tests. How does that not directly correlate that number to being the max volumetric speed of the ABS they used?
Please don’t give Bambu the idea to start any subscriptions. I feel if they take away our ability to use ALL functions unless we are in cloud mode that they should allot us a significant amount of space for profiles(which don’t take up much space).
Anything is possible, but the MVS value comes from those who make the parts of the tech involved, exceeding their specifications breaks their MVS as they have stipulated the use cases.
It would be the same as getting an extra 5 MPH out of a car engine by doing things that breaks the warranty.
I can see his point of view for the ABS as the test standard and them not listing it in the table. To get the max volumetric speed they used ABS for the test and to get the time savings they used PLA as listed in the footnotes above. I’m assuming they are hand picking the best results to get the highest numbers for the sales pitch.
Thats fine. However, they then show a table which has 3 different filaments(with their max VS) and then list a max volumetric speed that is higher than any filament in the table without a reference or footnote in that table to explain the higher number. Is that a theoretical max for all filaments? I don’t know as they only listed that they tested it with ABS above in a footnote that is not referred back to by the table. So they should at least put a foot note to refer to the material or test that achieved the “MAX” volumetric speed in the table. I’m assuming they tested all those filaments with that nozzle and that is the MAX for that specific filament in each column otherwise advertising would be all over putting the highest number they they got during testing for each filament. They don’t have to say ABS, but they should have the footnote in the table.
This is just marketing. Most HF hot end manufacturers test with ABS at a very high temperature like 280 or 300c. Print quality and layer adhesion will be subpar at those temps and speeds, but it looks good in the marketing. Once one manufacturer did it, all the others have followed to have comparable numbers, otherwise people would say “They call that a high flow hot end?! My “so-and-so” brand can do 20mm³/s more”.
Also just because it it can extude filament at lets say 60mm³/s and complete the max flow test, does not mean its a good idea to print at that speed. I tested some high flow PLA and the max flow test was able to do a bit more than 60mm³/s at standard temp, but i dont print at that flow rate unless its a prototype. Again it comes down to layer adhesion dropping significantly at max flow rate. There is a sweet spot somewhere between, I posted this video before but here it is again.
Very interesting video! Changed my mind about a lot of things. In fact, after watching I feel like the next piece of “must have” kit I need to build/buy is a tensile strength tester.
Lol, not from this video but last night I was thinking about building one. This way I can test my own prints and parameters. I was looking at some load cells on Amazon, I have a PLC in my shop already that I could use. I have some left over 20/20, 40/20 from an old 3D printer. I would just have to make the setup rig.
Hi Jon,
Since you’re already reading this thread, can you weigh-in with your opinion regarding the meaning of that last column, and how those numbers were arrived at? Among those of us participating in the thread, we never quite arrived at 100% consensus, though it appears we may have gotten close to 100%.
If you yourself are unsure, would you please ask your contact(s) within Bambulab? It probably won’t take the person who wrote it more than a minute to say, and it would be nice to tie this off with an official answer, even if the answer is “we plucked those numbers out of the air.” Then at least it will be a fully settled matter, and we can all move on.
