I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling
 
Notifications
Clear all

I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling  

  RSS
Rebra
(@rebra)
New Member
I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

Greetings,

Yesterday I assembled my first Prusa i3 MK3S+ kit. I "semi-assembled" Prusa MINI last year and have been using it ever since. I have about 800 hours of print time on it - and I'm very satisfied by it.

I mostly print PET-G by Azure Film.

The problem part now: When I print with i3 the PET-G keeps oozing a lot during bed leveling. The difference I noticed is that MINI warms up extruder up to 170'C than checks the bed leveling - and finally warms up the extruder to 230'C.

Why doesn't i3 do the same? (its has 3.9.3 firmware on it - but I doubt that its fixed in 3.10.0)

 

Hrvoje

Posted : 04/06/2021 12:12 pm
fuchsr
(@fuchsr)
Prominent Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

You can achieve the same behavior by changing the custom startup gcode in your printer profile. Take a look at @bobstro's excellent notes and copy/modify his example startup code:

https://projects.ttlexceeded.com/3dprinting_prusaslicer_gcode.html

 

Posted : 04/06/2021 12:51 pm
Rebra
(@rebra)
New Member
Topic starter answered:
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

So, this is not a elephant in the room? It's normal that they add this "feature" to MINI (acknowledging how it should be - or how it is better) but not to their flagship product?

I always believed that coming from MINI to i3 will be an improvement in almost every segment (except the price factor) but looks like i was wrong.

Native USB/Ethernet support - MINI yes / i3 no

Colored display with preview - MINI yes / i3 no

Smart preheating during "pre-print" phase - MINI yes / i3 no

 

MINI really looks like a better printer if it's printing space is enough big for you. If the staff is not active on the forum ill open a support ticket because this should be implemented in firmware or prusa slicer when generating a .g code.

 

Thank you fuchsr for fast reply - I saw few threads on this forum and reddit about PET-G oozing during pre-print and will probably be doing something like this.

But this shouldn't be the way this printer is used - the whole crowdfunding / community based product that is constantly improving itself through generations and updates shouldn't have THIS problem. I believed in this concept and still do.

Posted : 05/06/2021 6:04 am
fuchsr
(@fuchsr)
Prominent Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

While I understand your frustration, I'm not sure this is criticism is fair. The Mk3S+ is a much older model, and most importantly is limited by its 8bit board. There's another thread in these forums in which the Prusa guys are asking for input on how to fill the whopping 5K of free space they were able to squeeze out by way of some recent software improvements. Very timely to your comment, the devs just published a blog post on that very topic: https://blog.prusaprinters.org/prusa-dev-diaries-4-getting-the-most-out-of-8-bit-firmware_51082/

One reason I love my Prusa printers is that they do constantly improve them, even the venerable Mk3 series. But there's limits, and there's a point where only moving to a new model will open a path forward -- and that's going to be the Mk4. Everyone is waiting for news on that front, but given the comments Joe Prusa made about component shortages in their latest Live show, I'm not holding my breath to see it in the wild soon. And of course I'm hoping they will provide an upgrade path forward for us Mk3 owners, specifically a way to replace the ancient board.

As far as the specific topic of startup sequence is concerned, I can only speak for myself of course but I'm perfectly happy to have this handled in software, not firmware. If you dig up the thread on improving the 8 bit firmware I mentioned before, I think there are better ideas for utilizing the few extra bytes, that actually require firmware changes because they can't be handled by software.

Posted : 05/06/2021 10:05 am
Ringarn67
(@ringarn67)
Estimable Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling
Posted by: @fuchsr

While I understand your frustration, I'm not sure this is criticism is fair. The Mk3S+ is a much older model, and most importantly is limited by its 8bit board. There's another thread in these forums in which the Prusa guys are asking for input on how to fill the whopping 5K of free space they were able to squeeze out by way of some recent software improvements. Very timely to your comment, the devs just published a blog post on that very topic: https://blog.prusaprinters.org/prusa-dev-diaries-4-getting-the-most-out-of-8-bit-firmware_51082/

One reason I love my Prusa printers is that they do constantly improve them, even the venerable Mk3 series. But there's limits, and there's a point where only moving to a new model will open a path forward -- and that's going to be the Mk4. Everyone is waiting for news on that front, but given the comments Joe Prusa made about component shortages in their latest Live show, I'm not holding my breath to see it in the wild soon. And of course I'm hoping they will provide an upgrade path forward for us Mk3 owners, specifically a way to replace the ancient board.

As far as the specific topic of startup sequence is concerned, I can only speak for myself of course but I'm perfectly happy to have this handled in software, not firmware. If you dig up the thread on improving the 8 bit firmware I mentioned before, I think there are better ideas for utilizing the few extra bytes, that actually require firmware changes because they can't be handled by software.

The MINI handle it in startup gcode, like bobstro. So regarding the startup behavior I agree with @rebra. It would be an easy fix for Prusa to change I3Mk3's startupcode with a config update.
On the other hand, it is fun to do it on your own.

I am fully aware of the 8-bit boards limitation and the reason(s) I3 seems a little "old".

Prusa I3 MK3S+ (kit dec -20), PrusaSlicer, Fusion 360, Windows 10...
Posted : 05/06/2021 10:31 am
Rebra liked
fuchsr
(@fuchsr)
Prominent Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

No disagreement from me -- although selfishly I'm happy they didn't change the startup gcode because it means i don't have to update my custom profiles (which already do the cool down), hehe!

Posted : 05/06/2021 10:35 am
Ringarn67
(@ringarn67)
Estimable Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

@fuchsr

That IS a problem when they change something 😣 
Adapted bobstro's startupcode rather quickly when I understand what causes the oozing, and I have added some more along the way, just for fun

Prusa I3 MK3S+ (kit dec -20), PrusaSlicer, Fusion 360, Windows 10...
Posted : 05/06/2021 10:53 am
Neophyl
(@neophyl)
Famed Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

I think that's actually why they haven't done it.  It would be very very easy for them to make the Mk3 default profiles do the same as the mini (and the Bob profiles which were doing it before the mini was ever released) BUT and its a big but, the amount of tech support issues they would get is just not worth it.  Whenever they change something in the way a thing operates they get so many complaints that they did so.  

As this is such an easy thing for a USER to add themselves then from a company point of view its better to let those who want to do it just add it.  

If you think that wouldn't happen then I would direct you to the many threads on the forum and github where users have complained that their printers don't 'heat up' properly, they only heat to 170, not whats set in the filament profiles so they cancel the print.  Complaints about normal behavior just because the user doesn't know what to expect.  Now translate that to a user base who IS used to how it works and then suddenly it does not act the same anymore.  

Those users who suddenly have their perfectly working system changed have a point too.  I wouldn't like it if stuff was being changed on mine without me being aware.  That's one reason I don't use the defaults, just my detached copies.  I still let the built in ones update but none of it makes it into my profiles unless I copy the changes over.  

Posted : 05/06/2021 12:50 pm
fuchsr and Ringarn67 liked
bobstro
(@bobstro)
Illustrious Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling
Posted by: @rebra

So, this is not a elephant in the room? It's normal that they add this "feature" to MINI (acknowledging how it should be - or how it is better) but not to their flagship product?

The Mini is a newer product and the 2-step warmup was released on day 1. The Mk3 has an established base and has been out for years. The community has developed several variations on the 2-step warmup procedure, all of which are readily available. As much as I like it, there will be a chorus of caterwauling if Prusa changed the Mk3 profiles. People don't like change. So for now, Prusa left the existing procedure which works for many, many people.

I always believed that coming from MINI to i3 will be an improvement in almost every segment (except the price factor) but looks like i was wrong.

You're not wrong but you seem to expect everything to be how you want it. If you feel it important to use that procedure, Prusa has provided the means for you to do so easily 

Native USB/Ethernet support - MINI yes / i3 no

The Mk3 is an older machine and never advertised network connectivity as a feature.

Colored display with preview - MINI yes / i3 no

Again, the Mk3 is an older model and never advertised such a feature. (FWIW, I have replaced the touch screen on my Sidewinder with the same sort of display used on the Mk3. Color doesn't change operation.)

Smart preheating during "pre-print" phase - MINI yes / i3 no

You can install any of dozens of variations easily.

MINI really looks like a better printer if it's printing space is enough big for you. If the staff is not active on the forum ill open a support ticket because this should be implemented in firmware or prusa slicer when generating a .g code.

I suggest you add it yourself if you feel the lack of this feature is impeding your use of the product.

[...] But this shouldn't be the way this printer is used - the whole crowdfunding / community based product that is constantly improving itself through generations and updates shouldn't have THIS problem. I believed in this concept and still do.

The open source approach used by Prusa is what allows our community to continually tweak and tune beyond what was released by the manufacturer. This actively occurs with all Prusa printers. That doesn't mean every tweak is automatically deployed to every device, nor would such corporate control be desired. Those using their printers for production certainly don't want surprise changes. Compare this to many other products where you're stuck with old firmware and no slicer support and the benefits are pretty clear.

 

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 05/06/2021 2:29 pm
fuchsr and Ringarn67 liked
Rebra
(@rebra)
New Member
Topic starter answered:
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

@bobstro

I can live without those compared features (usb/eth...) and i know there are a lot of aftermarket additions that can improve or boost mk3s functions.

But the thing that I find troublesome is that this printer could not print this filament (maybe Prusa pet-g it can) "out of the box". If that is the case than (same as usb/eth support) don't advertise printing PET-G... The blob/string would be very large and a time bomb waiting to happen during print - the same it did first few prints...

I've added custom starting g-code as @fuchsr suggested and is better but still need to tamper with it to get MINI out of the box Azurefilm PET-G printing results. A foul proof method I'm using at the moment is preheating bed temperature to 85-90'C on the printer than running the print using that custom starting g-code.

If everyone is using custom start g-code why wouldn't they than implement a "good" starting G-code in Prusa Slicer that is capable of printing PET-G.

 

@bobstro

So you can say that my expectations about printing PET-G out of the box is my custom/specific wish that no one else desires and I can live with your statement - but I don't think it's a objective thing to say.

 

I know I will get it working but to be a bit philosophical: we have limited time in this life and the older I get the less time I prefer to "waste" on unexpected problems that are in range of "child illness".

Posted : 06/06/2021 6:41 am
Ringarn67
(@ringarn67)
Estimable Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

@rebra

**Read the following with a big smile on your face**
Sorry Rebra 😌, but after reading neophyl and bobstro I have to change my mind, they are absolutely right, Prusa will have a lots of questions to the support about the new behavior of their printer....
**Now you can stop smiling 😉 **

And, as said, not much work for those who want to change the startup-code

I have printed PLA, PETG, PC Blend, ABS on my i3 kit with good result. Not that much abs or pc to be honest. PLA and PETG works great.

Upload a zipped 3mf-file that didn't work. I am sure someone has an idea

 
Prusa I3 MK3S+ (kit dec -20), PrusaSlicer, Fusion 360, Windows 10...
Posted : 06/06/2021 11:30 am
bobstro
(@bobstro)
Illustrious Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling
Posted by: @rebra

[...]  the thing that I find troublesome is that this printer could not print this filament (maybe Prusa pet-g it can) "out of the box". 

You only mentioned issues with oozing at the start that you felt would be addressed using a 2-step warmup process as used on the Mini. Other than that, what do you mean when you say "this printer could not print this filament"? I'd hardly consider a bit of oozing at the start of a print a major issue.

I've added custom starting g-code as @fuchsr suggested and is better but still need to tamper with it to get MINI out of the box Azurefilm PET-G printing results. A foul proof method I'm using at the moment is preheating bed temperature to 85-90'C on the printer than running the print using that custom starting g-code.

Without a better description of what is actually wrong, it's hard to provide suggestions, sorry.

If everyone is using custom start g-code why wouldn't they than implement a "good" starting G-code in Prusa Slicer that is capable of printing PET-G.

Because:

  1. Thousands of users have been printing PETG on the Mk3 without problems for years, and
  2. If Prusa shoves a major change out, it may well disrupt those same thousands of users who are not having problems.

They may eventually put something out, but it makes sense that they're not going to "fix" a problem that the vast majority of users are not having problems with.

[...] So you can say that my expectations about printing PET-G out of the box is my custom/specific wish that no one else desires and I can live with your statement - but I don't think it's a objective thing to say.

The only thing I've stated is that implementing a 2-step startup procedure on the Mk3 to equate to what's done on the Mini is not difficult. This is what you were asking about in your post. At best, it's a convenience and hardly something that is going to make or break a print, but it is an easy enough fix.

I know I will get it working but to be a bit philosophical: we have limited time in this life and the older I get the less time I prefer to "waste" on unexpected problems that are in range of "child illness".

You could always use a filament that has a tested, known-good profile already developed. Getting a new filament working is not particularly difficult, but if you insist on spending no time mastering the basics, stick to profiles that are already tested.

If you'd like some help creating a good profile for this filament, save your current  3MF project file, zip it up, and attach it to a reply here so we can see your part & settings and give better recommendations. If you just want to complain that your Mk3 is not as simple as a toaster, nobody here can really help you.

 

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 06/06/2021 4:53 pm
Rebra
(@rebra)
New Member
Topic starter answered:
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling

If there is a 10 cm string oozing during pre-print phase than there is a big chance that it fill ruin that print (blob or string) in some phase of the print.

Again that problem is not there "out of the box" with MINI.

That statement was connected to your statement that MK3 has no advertised USB/ETHERNET support - I know it doesn't I was comparing a budget vs flagship model and their specifications.

In my opinion if there is a string 10-15cm long that becomes a blob or stays a string and latches on something is a failed print. So following that train of thought they shouldn't advertise PETG (out of the box) support - or at least only Prusament PET-G out of the box compatible. But I think MK3 got out before they started doing Prusament.

I have no problem printing afterwords - I was complaining about out of the box/default printer setup compared to MINI that I used for 800 print hours and this same filament.

To be honest, I printed few prints using Snapmaker 2.0 and it has a great last step of pre-print procedure. It brushes the nozzle on the end of the plate effectively cutting the excess filament of - a dangerous and effective "move".

 

If this company has a mission/vision to make 3D printing for everyone and in every household this should be a thing to implement as well (the same way they did it in MINI - suggesting it's a superior DEFAULT technique).

I thank @fuchsr for that example-guide and hit prompt replay.

 

It's easy to badmouth a company or a product. But I would like for this company and their products to be better than they were yesterday - if there is a room for improvement.

Posted : 07/06/2021 11:57 am
bobstro
(@bobstro)
Illustrious Member
RE: I3 MK3S+ vs MINI pre-print aka oozing PET-G during bed leveling
Posted by: @rebra

If there is a 10 cm string oozing during pre-print phase than there is a big chance that it fill ruin that print (blob or string) in some phase of the print.

That sounds like more than the usual ooze that occurs as the nozzle is warmed. I'd open the extruder up and examine the top of the heater block to make sure no filament is leaking out. If so, that indicates the nozzle isn't properly tightened up against the heatbreak. This can produce persistent ooze throughout the print.

[...] That statement was connected to your statement that MK3 has no advertised USB/ETHERNET support - I know it doesn't I was comparing a budget vs flagship model and their specifications.

I know "flagship" consumer products are put out every year and are expected to include every new feature. Prusa printers are put out far less regularly, and are "flagship" in terms of build and print quality, reliability, and support. In many ways, this requires more of a "include it when it's stable" approach rather than pushing out every possible feature for every printer annually. Even the older Prusa i3 Mk2 is still considered a quality printer up against others that are 4-5 years newer. When looking at tools, reliability tends to trump features. I'm sure Prusa will be introducing new models in due time (when they're ready) and will include new features, along with an upgrade path for current Mk3 users. We don't know what that looks like yet.

In my opinion if there is a string 10-15cm long that becomes a blob or stays a string and latches on something is a failed print. So following that train of thought they shouldn't advertise PETG (out of the box) support - or at least only Prusament PET-G out of the box compatible. But I think MK3 got out before they started doing Prusament.

Blobs and stringing should not be ruining your prints. If they are, I'd focus on pinpointing the issue. The 2-step warmup routine used on the Mini is NOT going to resolve large-scale problems. If you tweak the startup gcode, you can include a modified prime line to trap ooze (see example here). Note that adding a small "wipe" move to the end of the prime line can help trap ooze, and that feature is not present in the Mini start gcode. This is a good example of why the ability to modify features to your specific needs is helpful.

I have no problem printing afterwords - I was complaining about out of the box/default printer setup compared to MINI that I used for 800 print hours and this same filament.

My SUV performs very differently than my sedan. It cost more, but the sedan has some nice features. They do different things. Unlike a much more expensive vehicle, I can modify my 3D printer to provide parity on most features between different models and even manufacturers. Not sure what else to say there. If you want to request new features or capabilities for the next i3 iteration, of course you should do so. I'm just pointing out that this isn't a "defect" in the product. At present, they are different printers with different capabilities. The Mini benefits from being newer and increased processing power.

To be honest, I printed few prints using Snapmaker 2.0 and it has a great last step of pre-print procedure. It brushes the nozzle on the end of the plate effectively cutting the excess filament of - a dangerous and effective "move".

You can do the "wipe" action at the end of start gcode that I mentioned which moves the nozzle quickly back and forth with zero extrusion at the end of the prime line. Someone recently posted a full "wipe bucket" addition that they've added to their printer. In reading up on other printers, these tend to produce mixed results. The same with various "wipe pads" and brushes. The Marlin firmware actually includes a number of such routines. Needs will vary if you're using a MMU (something not available on the Mini). Again, not something everyone needs or wants, or will be willing to pay extra for, but certainly doable if you feel it's important.

If this company has a mission/vision to make 3D printing for everyone and in every household this should be a thing to implement as well (the same way they did it in MINI - suggesting it's a superior DEFAULT technique).

Oh, I'm sure Prusa will add those features. Just saying there are reasonable assumptions as to why they haven't done so yet. 

It's easy to badmouth a company or a product. But I would like for this company and their products to be better than they were yesterday - if there is a room for improvement.

Absolutely, and agreed 100%. If you want to contribute, Prusa welcomes filament profile contributions. You can make firmware and slicer feature requests over on the Prusa GitHub pages where they'll get much more attention from the developers than it will here (this being only a user-user forum). I'm just pushing back a bit on the idea that this is a pressing issue that is preventing the Mk3 from doing everything it is advertised as doing. They may add features in the future.

 

My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 07/06/2021 2:53 pm
Share: