I ordered a H2D today and this will be my first Bambu, so apologies if this question seems stupid.
Anyway, currently using a Prusa MK4S with MMU3 (single extruder, multi material unit) and on the Prusa there is no cutter at the extruder and the one cutter in the MMU3 has actually not been used once since I own it.
I understand with Bambu, before pulling back the filament it actually cuts it close to the hotend (according to the Wiki I’m reading currently). Why is it done that way? Doesn’t it mean extra waste and extra purging?
The Prusa makes a special procedure (ramming) before unloading the filament which forms a small tip at the filament and then it’s removed from the PTFE tubes.
Is it possible to use this the same way on the Bambu?
Is the filament cutting (Bambu) versus ramming and unloading from nozzle (Prusa) the reason why Bambu poops and Prusa doesn’t?
Don’t understand.
I purchased a new printer, spending the time reading the Wiki before it will arrive, trying to understand everything so I can directly start printing since I’m really looking forward to it.
Simply cutting the filament is very reliable, as you will always get a well-formed tip. Prusa on the other hand relies on tip forming, which is quite tricky to get right. And each different filament type needs different tuning.
As long as Prusa gives you working filament profiles, everything is fine. But believe me: tuning tip forming is not fun at all.
Personally I much prefer the way Bambu does it. I don’t care about the additional waste if it means that filament changes succeeded basically every single time.
@MalcTheOracle:
I really don’t get why you’re blaming them for asking questions. They weren’t complaining or ranting, just asking.
You’re not contributing anything useful to this discussion.
Thanks, @Rolf, good explanation, so this is about process reliability then.
I never had any issue with the ramming procedure (yet) so no single load/unload procedure failures but I see the ramming parameters in the slicer (big amount of different values) and I guess to get these to the point where they work reliably must have been a nightmare for Prusa.
I purchased the AMS bundle anyway but I guess I will rarely use it, mainly bought the dual extruder printer for support materials.
I was further asked about due diligence. I suggested that learning about a feature so fundamental to the printer after the purchase appears to be the wrong way around.
What was blaming about that?
I also added additional information about an upgrade that the OP, probably wasn’t aware of.
I am confused why you throw shade without any basis in fact nor any examples. It appears you are doing to me, what you mistakenly believed I was doing.
Not an authority on why since hard to second guess decisions others make but as to extra waste and purging - maybe. The extruder looks like it has a pretty small volume though so purges out pretty quick. Once you see it in action you’ll see. But it is waste and extra purging but not huge - depending.
On the other hand, Bambu has run at least one contest on what to do with purged filament.
And how much waste you generate depends on what you print. If just doing single color doo-dads you won’t generate much waste at all. Models with color changes on lots of layers can be problematic though and can even generate more waste plastic than is used in the model itself.
Also, and it may or may not be true for you, but I’m sure I’ve wasted more filament refining, printing, and improving models than in color changes but that is very workload dependent.
And you’re sidestepping a lot of purge waste with a two head printer depending on how many colors you may end up using and what you print.
Ramming a high flow nozzle is not really a good thing to form a tip if you ask me.
Possibly your Prusa didn’t have a high flow nozzle with multiple internal channels.
I have a Prusa MK2.5s with MMU2s and an X1c. With the Prusa and many modifications, I would rarely be able to create a whole multicolor print without intervention. The X1c is much better. Yes it wastes more, but cutting the filament means you don’t have to worry about the tip… Plus on the Prusa you also had to worry about rewinding the filament or create a way to mange the filament. The MMU3 is supposed to be much better.
Actually, it does, and it works, but it is not recommended because of extra purging required since the filament seems to be rather sticky in the channels.
Most of the time therefore I use the standard nozzle even for single material prints.
Btw, that’s one of the things I’m really looking forward to with the Bambu: Quick-swap nozzle. That’s a pain with my MK4S - But different topic.
Not confusing at all, I simply consider it plain … (being polite here).
If I was reading full manual and wiki of every product that I’m buying in advance (like for the printer, I wanted a bigger one than MK4S and proper housing) I would spend many days just reading.
Have you been fully reading the H2D wiki? How many hours did you need?
And this kind of time you spend for all the competitors you are considering? Again, that’s plain …
And even if you are really doing that: Good for you. Don’t expect the majority of people on this planet have so much time.
But I don’t believe you wanted to help like @Rolf did. And I’m sorry if you felt insulted by me asking a technical question.
The whole color process with filament buffer etc. is a pain in the backside with my MK4S + MMU3. The operation (filament changing, rewinding, etc.) is really inefficient so I leave the same spools connected to MMU3 95 % of the time.
Btw, not wanting to start a pro/contra since I was mainly interested in the technical background (which has been answered): besides the manufacturer needs to invest a lot time to get the process reliable - ramming has a significant disadvantage: it slows down the color change process which also brings technical disadvantages besides the extra time needed so I’m not unhappy with a faster color change process.
But I would have been more happy if I was able to choose - cutting or ramming. No big deal though.
From your first question, you explain you purchased a new printer and are only now looking into why it does a fundamental action and can it do it the same way as a different printer.
I answered that.
If you feel insulted by someone questioning why you would make a large purchase and then do your investigation, then that is nit my problem.
I think this all boils down to this question…
Do you investigate purchases prior to making them so you know what you are purchasing so the product does the job, will work within whatever existing solution I already have and so good money isn’t wasted?
Yes, of course I do.
That should not be a surprise, that is due diligence, something many do before they make such purchases in and out of the 3D printing world.
I did help, like I always do, it was your choice to get annoyed.
My question about your clear lack of prior investigation was never answered, had you of done, I would have had more to go on.
Your question lacked related information that could have been gleamed had you of engaged rather than being unnecessarily hostile to the question.
Nice passive-aggressive phrasing, I am not sure if that was intentional.
It was far from technical as I stated initially, it is a basic design feature of all Bambu Lab printers irrespective of an AMS in the mix.
That is great, a change from the implied disappointment from the initial question though.
If you do not like people asking follow up questions, you may wish to furnish more information initially.
Being rude to those who offer help and suggesting those people have ill intentions isn’t a great way to gain future help.
Neither of you were able to indicate where I was rude, perception isn’t facts.
Perception isn’t facts, but communication failures happen regardless. And, regardless of the tone you intended, this:
May I ask why you didn’t do your due diligence before you purchased the printer?
…came off sounding a little harsh.
@MK4S_H2D Malc is very knowledgable and helpful on the forums, but sometimes does come off sounding harsher than I believe he means to. I’ve learned that it’s almost never personal, and there are good reasons to be cranky some days.
Please continue asking questions to learn more. I learned something today – I had no idea how the Prusa MMU3 changed filaments at the extruder.
I love seeing different kinds of solutions. Prusa took an elegantly clever approach: very very very carefully change the temperature, push to form a nice tip, then pull it back. Bambu took an elegantly brutal approach: just cut it off.
