A message to Jo Prusa  

Re: A message to Jo Prusa

sorry i'm not Jo P.

Since you posted and i'm curious could you elaborate on the biggest complaints or problems you are having that are most aggravating?
i'm far from the biggest fan boy of prusa and sometimes the support staff i've dealt with in the past.

as a hobbyist i treat these printers as far from a commercially ready for market product so i'm used to a lot of hands on fabrications and field repairs on these things. i have personally voiced my problems on the Mk3 printer over the past year or so.

just would like to learn what i can from the problems you are having that drove you to this point.

Re: A message to Jo Prusa

Something like six Kg of wasted filament and countless hours lost have taught me that it is just impossible to expect any reliability with this device which is good for nothing.
I am not a beta tester, I am an end user, therefore I bought the machine to be used, and unfortunately the only thing that it is good for, is just to sit perched on top of the printer.
And it is not that the machine is difficult to tune (which it is) or that it is so heavily dependent on the filament type you are using (also true), it is that even if you manage to set it up correctly, you will have to cross your fingers and pray to your gods to get a good print, but most likely your gods will not hear you.
Of course you have seen some beautiful printed parts made with the MMU2, and anybody can make them. It is easy. You just have to babysit the printer during the entire task, but this is not what I bought this thing for. I feel scammed.

Re: A message to Jo Prusa

i agree 100%. for me i treat the MMU2 as experimental with the hope that as a collective it will improve. but a ready to go workhorse it isn't and neither is the MK3. every-time i setup a print i tell myself it is in the hands of the gods and i hope for the best.

in order to have some success i choose not to fight with the filaments i just use one that might give the better results with and standardize everything, i keep everything with the same companies depending on the material. i figure in addition i can then count on the filaments of different colors to act similar and stay in the same range of temperature.

with PETG being so stringy i figure at this point it would just be a setup for failure on a MMU. however from testing that Prusa PETG strings way less and has some better properties then other PETG, i had pure hell with Hatchbox PETG and stay away from it.

i complained pretty loudly on the MK3 myself as a huge disappointment it is such a step down from the MK2S that all you can do is throw up your hands and scream. on paper it should be amazing.

i don't know if you just want to give up 100% at this point or keep trying. sometimes your just so fed up with something it is better to move on. i looked at your other posts and can see your filament issues and questions that went unanswered. i didn't want to post in them since you at this point.

on your filament post:
1- A database with settings for different materials, brands and colors that produce perfect tips
2- A comprehensive guide of how the different settings (temperatures, speeds, cooling passes, ramming, etc.) do affect the shape of the tip.

1) i wish something like this was possible, there is just so many variables that make one setting work for one person and doesn't work for another. even if you buy the same filament it may give wildly different results. all you can do is try some things to reduce variables a little. it would depend on your setup and environment. oh god and all the different slicers that all run different and drive you insane.

2) this would be nice Slic3r documentation sucks for normal people that do not spend hours on github combing the source code.
what i found was pretty much only 2 things really did anything.

the Ramming time increasing or decreasing and you really can't play with much that i understand other then the seconds

and unload speed at the start. going over 100mm/s makes it stringier and going under down to about 70 makes it less stringy but ever so slightly and then go too low and the system jams.

the biggest control factor appears to be temperature and everything else is just going to be a slight adjustment.

i'm running my machine stringy and i saw what happens when the entire system gets clogged up with one filament that got really stringy. i used that inland PLA setting and it got better but dropping even 5C on that really bad one was the only thing that worked.
then you compensate with lower range temperatures it means you have to manually slow all the speed settings down.
like infill has to be readjusted from 200mm/s to 90 or less because now at the lower temps the layer bonding at higher speed mean less fusion on layers or it acts like under-extrusion which can also look like layer skip sometimes.

i wish i new secrets, and it is rare when people share any settings because i can tell you usually the dam settings only work for that one person in their environment with their own lot of filament.

i wonder myself how people get perfect layers at least with the MK3 LOL and amazing looking almost commercial surfaces. but i temper my expectations with the fact this stuff is still like the computers of the late 1970s and still lurks in the hobby area waiting for that leap to a home consumer ease that we all want of plug and play.

i would say fighting for a perfect tip most likely is not in the card and it is a search for exactly what is a major cause of problems. and can you just get the machine on the edge of tolerance to get some work out of it.

again i know zero about your setup and i setup my stuff in specific ways to try and reduce environmental factors.

since prusa stays off the forums it is just the end users trading advice or fixes i wish prusa would come around a little as this total hands off approach sucks and they keep rolling out products too dame fast with heaps of problems some will never be fixed or addressed. slap that MK4 label on the box right.

if your done then hey i understand get your money back because nothing will satisfy. if you want some help well i'm a noob honestly i have about 2 years of experience in printing, made a bunch of my personal designs that i never released to the public i'm a hobbyist and i have seen people on here with much more talent then me come up with some amazing solutions to problems.

it is up to you.

Re: A message to Jo Prusa

If you guys need help from the community, this is the right place. Be kind, describe your steps/issues one by one in detail and you will get many good hints. Anyway fixing stuff/dialling in and understanding the issue is still up to you.
If you just want to complain and rant, I would suggest to contact either support directly, email or social media. This are better channels to reach out to PR.

Re: A message to Jo Prusa

Thanks Daniel
Filament settings: I do not think there are so many variables. I bet your printer is in a room with a temperature ranging from 20 to 23ºC and a relative humidity ranging from 40 to 65%, same as mine, same as most of the printers. So if we are using the same filament with the same settings we should get similar results.

Ther reason that nobody has published their settings it is just because NONE of them will really work 100%, and I think that it is because there is a random factor to the tip shaping that cannot be controlled, which means that the procedure is fundamentally flawed and thet the device will never work reliably. PRUSA have to know this, and the fact that they are still selling the device well knowing that it will never work in its current form speaks loudly of their ethics.

Another thing that burns me is them using trolls in the forums to keep their sales up. My chinese phone works alright, so I have not visited any troubleshooting forum about it, same as my car, same as my dishwasher machine. So, what is all this people that have perfectly working MMU2 doing in these forums? Stinky at the least.

Nikolai,
I take it you do not like critics, do you? I did try to get help in the forums, and I tried some of the suggested solutions (like the springs in the bowden tube). Nothing has worked and now I have given up. Mine was not a rant, but a clear message to Jo Prusa and an advice to all the people who is thinking about buying a MMU2. I am helping both of them, to Jo PRUSA how not to ruin stupidly his company and to the buyers, how not to get scammed.

Re: A message to Jo Prusa

Are you using the Mk3 heat break or the stock E3D one (have you ever replaced the hot end)? I had all sorts of trouble with tips until I went back to the mk3 specific heat break.

Re: A message to Jo Prusa

Nikolai,
I take it you do not like critics, do you? I did try to get help in the forums, and I tried some of the suggested solutions (like the springs in the bowden tube). Nothing has worked and now I have given up. Mine was not a rant, but a clear message to Jo Prusa and an advice to all the people who is thinking about buying a MMU2. I am helping both of them, to Jo PRUSA how not to ruin stupidly his company and to the buyers, how not to get scammed.

I don't take your post personal. So none critics were done in my direction. Mine MK2/MK2S/MK3 and MK3 with MMU2 are working fine and printing without me sitting in front of it. And no, I'm not related to PR in any kind. Just a regular customer.

The only weak spot I see on the MMU2 is a filament path. Everything need to be perfectly adjusted. On my unit I'm doing it one by one. Means printing one model and see when my intervention is required and why. Based on spot and kind of the issue, one thing (like temperature) is being adjusted and let the print finish. Any hardware modifications like changing the spool holder is being done after the print.

Regarding the slicer settings, I'm still using default ones, no changes. Currently a 20 hours job with 650 filament changes is printing fine and is nearly finished.

Again, if you want some specific help, feel free to describe your current issue and what kind of modifications you've done to your hardware.

Re: A message to Jo Prusa

Thanks Daniel
Filament settings: I do not think there are so many variables. I bet your printer is in a room with a temperature ranging from 20 to 23ºC and a relative humidity ranging from 40 to 65%, same as mine, same as most of the printers. So if we are using the same filament with the same settings we should get similar results.

Ther reason that nobody has published their settings it is just because NONE of them will really work 100%, and I think that it is because there is a random factor to the tip shaping that cannot be controlled, which means that the procedure is fundamentally flawed and thet the device will never work reliably. PRUSA have to know this, and the fact that they are still selling the device well knowing that it will never work in its current form speaks loudly of their ethics.

Another thing that burns me is them using trolls in the forums to keep their sales up. My chinese phone works alright, so I have not visited any troubleshooting forum about it, same as my car, same as my dishwasher machine. So, what is all this people that have perfectly working MMU2 doing in these forums? Stinky at the least.

Nikolai,
I take it you do not like critics, do you? I did try to get help in the forums, and I tried some of the suggested solutions (like the springs in the bowden tube). Nothing has worked and now I have given up. Mine was not a rant, but a clear message to Jo Prusa and an advice to all the people who is thinking about buying a MMU2. I am helping both of them, to Jo PRUSA how not to ruin stupidly his company and to the buyers, how not to get scammed.

I've actually found even in similar environments with the same settings and filament to have vast differences. spool to spool a lot of this stuff varies. i've had one machine at the office do all kinds of stupid stuff when i was grabbing garbage from matterhackers.

at that point i switched to more expensive brands and even then i had one spool that was like beyond bad and i returned it there was some people with the same problems on amazon.com doing reviews at the same time having the same issues. slightly differen LDO stepper motors and slightly different pulleys and then there is the differences in tension and how much friction the machines have. long/short stick the same settings in 2 machines with the same product even in the same room and get slightly different results each time.

it seems stupid but you start asking additional, what seem like irrelevant questions, because they all kind of add up. Little things add up to big things.

besides temperature or humidity; is there drafts, are you running in an enclosure, oiling the rods, belt tightness, how stable is the table you are on, is the machine level, had the machine broken itself in properly, it just goes on and on the idea being if you can take some of the variables out you may get closer into figuring out a repeatable failure that can be corrected. it could very well be that your go to brand just will not work in a multi-material machine. currently the way they even test filaments is they assume it is always going in a single extruder. what if the dye in some cases caused a reaction with another filament dye they wouldn't test for it.

but getting into the stupid details would have to mean wanted to continue to fart around with this machine or just a direct abort and move on.
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"the reason that nobody has published their settings it is just because NONE of them will really work 100%"

very true and it goes back to how different everyones machine runs and also a setting could would well for a specific size and shape of STL but not others. sometimes you have to hand edit Gcode cause the slicer can only get you in the ballpark you have to find the seat yourself and it is frustrating.

" I think that it is because there is a random factor to the tip shaping that cannot be controlled, which means that the procedure is fundamentally flawed and thet the device will never work reliably."

Yes and with this design timing on every aspect is critical, they robbed peter to pay paul here. removing multiple extruders means higher rates of failure due to more moving parts that can cascade fail rapidly. at the same time going this route is cheap and you kind of get what you pay for especically with technology this new and uncharted.

for me i'm used to running VERY timing critic systems so i do things very differently sometimes compared to people on this board.

as example i was basically crucified because i go against the flow on "octoprint when running from a raspberry pi"
without muddying the conversation, the PI had timing problems with USB ports and i can see the increase in defects not only to the prints when using it in place of direct SD card use, but also physical machine damage. of course people have used octoprint and call me names because i disagree and even with evidence they don't want to see the problem.

"PRUSA have to know this, and the fact that they are still selling the device well knowing that it will never work in its current form speaks loudly of their ethics."

yes i cannot believe that somebody didn't scream out there is a problem here and we could do better but they are running a First to market gets the money business model, get it out there SELL and then fix it if we have time. this is where the community comes in in that everything is open source and many times we end users have fixed major problems while prusa made us sit and spin, sometimes the screaming is so loud they hear us over there.

it comes back again to expectations me very tempered and low, but at the same time when they work they are magical.

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"Another thing that burns me is them using trolls in the forums to keep their sales up. My chinese phone works alright, so I have not visited any troubleshooting forum about it, same as my car, same as my dishwasher machine. So, what is all this people that have perfectly working MMU2 doing in these forums? Stinky at the least."

i think when somebody does love something they are blind to the problems or the love can out weight problems that others see as critical.

what is a perfectly working MMU2?, when i look at my prints or others even in this sub forum, i see lots of issues with how the layers went down, stringing, the crappy MK3 moire patterns, inconsistent extrusion, dots, hairs, bleeding Etc. if a perfectly working MMU2 is i got something out and the machine didn't catch fire(lol) then i'm there, but there is just always something that isn't 100% right on any print i've done, if it met minimum standards then pat myself on the back while crossing my fingers.

my new acura sucks compared to my old one from 15 years ago i've had to go on the forums cause the stupid SMS doesn't work with my iphone, not to make light but i swear as this simple crap gets more complicated it just goes wrong faster now then ever before.

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I guess it comes back to deciding if you wish to continue which leads to some of the stuff you already tried but maybe one or two you didn't and then how much bending you will allow where you can't do what you want you have to do what will give the machine a better chance of success, that might mean having to spend more money to make it happen. sometimes it also pays to watch some video that is really boring on the MMU and seeing if you can catch any information that may at least set you on a path of solution.

sometimes you also just have to put something away for a while.

when i got my MK3 originally i was so fed up with it that i cancelled 2 more mk3 preorders. I threw my MK3 back in a box for about 4 months and i bought 4 MK2S machines which i setup as a print farm for various tasks the MK3 could not do and in fact it still can't do to this day even with over a years worth of revisions. that MK3 sat in a box until this summer when i needed to test out some stuff and needed a crappy 3d printer to just get some PLA work out of. by then a major problem with the firmware had occured and actually made my printer usable. OMFG i can't tell you how bad it was at the beginning i wanted to throw it at the wall and stomp on it.

well sometimes its good to let the RANT out and then go Team kill on COD or something LOL!

Re: A message to Jo Prusa

for fun, here is something i did with regards to a MK3 rant.

this is single material print from a MK3 of a 1/12 remote control car of my own design

ok so you look at that and even if it is the ugliest thing in the world you go what is wrong with it?

and i say well this was one that came off a MK2S

and then go yeah? so i still don't understand what is the problem?

and then i say well i have output from both machines side by side and the MK3 version sucks, it sucks bad, however you look and go
"dan you are crazy" and i say yes you are right but i'm not wrong because i have both side by side and as a newer machine the MK3 runs much worse then the older one. that is the problem. as some industry standard some might say it is a mona lisa what on earth are you complaining about.

so it goes back to what is a successful MMU print in that just getting a machine to complete one might be the best thing ever to somebody.

Re: A message to Jo Prusa

i'll also point out a possible situation. lets say when you first got the MMU2 it seemed to work better far from perfect but you do remember it was better. that first REALLY bad jam that occurred could of damaged something that was not visible without taking the entire assembly apart after that initial damage occurred it opened the door to additional problems that caused additional damage and the machine downward spiraled into something that will not work at all now.

now you have to play detective and if you bought the machine pre-assembled from prusa then it makes things even harder because you have to start over but on top of that undo somebody else's possible mistakes.

Re: A message to Jo Prusa

Hi Jo,
I'm sorry to say it, but your MMU2 is Totally unsatisfactory. I hate it.

I would send it back along with your MK3 and get any dual printing machine that really WORKS.

I feel completely deceived by you, and now, I am completely sure that when anybody writes saying that the device works flawlessly, he is a marketing agent of your company, and he is lying, and, what it's worse, you know it, and you are paying for his service to praise you, but yes, I know, you have to keep up the sales, so anything is valid. With this way to go you deserve going bankrupt, and we both know you will. MMU2 product says it's unavoidable.

And it is not that I have not tuned the device or that I haven´t tried enough. It is just that the thing is a Failure, and you know it, but you are still selling it anyway. Tonight, when you go to bed, think about your company ethics, and where do they lead.

Text moderated by Joan.t 17/11/18

Sorry to hear that you have been having problems with the MMU2, I spent the first few weeks trying to get mine to work, the hardest part about troubleshooting it was that Prusa really hasn't given any sort of troubleshooting guide with regards to getting good filament tips. I've heard that they are working on one. I've gotten more information from watching Chris Warkocki's, an MMU2 beta tester, video ( ) than I have from Prusa. And it seems like the original beta testers (I say "original" because we are all actually beta testers) were having the same problems that a lot of us are having. So my question is, why hasn't Prusa published an extensive MMU2 troubleshooting guide by now?

Now with that being said, I discovered that my real problem with my MMU was not the unit itself, and not how I put it together, but with my nozzle! I was using an Olson Ruby Nozzle, and I found out that the top of the ruby inside the nozzle is flat, not tapered like all other nozzles. I was never going to pull a good tip off of a flat surface. It wasn't until I switched over to the stock brass E3D nozzle that I started getting good tips on my filament. I had spent countless hours changing settings, trying different filaments (even bought some other brands to try), and any other thing I could think of. Nothing I did would fix my problem with stringing, malformed tips. When I ran out of ideas I asked myself "What is different about my machine than those that have working MMUs?". Then it dawned on me, I did not have a stock nozzle! So I changed out the nozzle, figured it couldn't hurt, and it wasn't something that I had tried yet. Instantly my tips were way better! I still had to adjust filament settings to tweak the stringing on the tips, but at least now when I made a settings change I actually saw a difference in my filament tips. Where as before with the ruby nozzle I didn't see any changes.

So, in all actuality it wasn't Prusa's fault at all with regards to sending me a non-functioning product, it was actually my modification to the printer that was the issue. Now I'm not a "Fanboy" of Prusa, yes I like the MK3, and the MMU2 that I purchased from them, but I also know that with regards to 3D printing there is no real "Consumer Ready" 3D printer. There is no printer, I'm aware of, that any person off the street can buy, take home, put in filament, press print, and have a perfect print. They all need adjustments, tweaks, upgrades, etc. And HELL YES it gets frustrating at times. That's why I consider 3D printing a hobby, and what hobby doesn't get frustrating at times.

So I have to disagree with you when you say that Prusa is selling a failed product. It's not a failed product, it works, it just may need some troubleshooting. But I do agree that Prusa needs to up their game with regards to helping the community troubleshoot their product. And they could start by checking the forums once in a while instead of leaving it up to us to help each other.

Speaking of helping each other, I can't help but respond to carlos.b6...

"Another thing that burns me is them using trolls in the forums to keep their sales up. My chinese phone works alright, so I have not visited any troubleshooting forum about it, same as my car, same as my dishwasher machine. So, what is all this people that have perfectly working MMU2 doing in these forums? Stinky at the least."

...I have a working MMU2, it still isn't perfect, it hangs up from time to time, but it works. I hang out in these forums so that I might be able to help others that are having the same problems I had, so if that makes me a "Troll" so be it. 😈

Re: A message to Jo Prusa

just to avoid confusion:

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Speaking of helping each other, I can't help but respond to daniel.a6...

"Another thing that burns me is them using trolls in the forums to keep their sales up. My chinese phone works alright, so I have not visited any troubleshooting forum about it, same as my car, same as my dishwasher machine. So, what is all this people that have perfectly working MMU2 doing in these forums? Stinky at the least."
----------------------

this was a statement from carlos.b6 not me. i quoted him a response from one of the posts above on page 1.
Carlos felt that the forum had some people employed by prusa giving biased information.

this was not how i felt about the matter.

Re: A message to Jo Prusa

just to avoid confusion:

-----------------------------
Speaking of helping each other, I can't help but respond to daniel.a6...

"Another thing that burns me is them using trolls in the forums to keep their sales up. My chinese phone works alright, so I have not visited any troubleshooting forum about it, same as my car, same as my dishwasher machine. So, what is all this people that have perfectly working MMU2 doing in these forums? Stinky at the least."
----------------------

this was a statement from carlos.b6 not me. i quoted him a response from one of the posts above on page 1.
Carlos felt that the forum had some people employed by prusa giving biased information.

this was not how i felt about the matter.

Dogh! I stand corrected, sorry about that. 😮 😳

I will edit my post. 😀

Re: A message to Jo Prusa

I wonder if all my print reliability problems come from this hardware failure:
In the first photo the PINDA probe connector is unplugged, in the second photo the PINDA probe connector is plugged in.
In both photos the PINDA probe is in my hand. My question is: Shouldn't the lights be green in the second photo?

Sometimes the device gets into this zombie state where it needs several attempts to start and I only get five orange lights, though there's nothing in the pinda probe. Normally the lights turn green on their own or after a few OFF/ON cycles but the other day they didn't and the machine was copmpletely unusable adding to my frustration. The next day it started OK... Today it does not want to work and will not give me the green lights to go again. Am I fighting against a faulty contact, a defective card or something like that?

Re: A message to Jo Prusa

i don't know enough about the light gauge operations on these units, but sure looks like you found either the main cause or could be one of more problems. i would contact chat and see if one of the techs can verify an intermittent failure. i read somewhere you could use a ohm meter to test the PINDA/Finda probe, and i know they can get damaged easily at the top of the probe if you bend the wire too much. or apply force down on the top of the probe pinching the wires.

Re: A message to Jo Prusa

I agree with daniel.a6, it sounds to me like you may have a broken wire in the FINDA probe. Sometimes it makes a connection, sometimes it don't. And to answer your question, yes, the light should be on in the probe if it's not near any metal. Have you tried moving the wires to the probe around and see if you get any changes to the lights?

But this definitely sounds like a component issue, and I recommend contacting Prusa through the Help Chat.

Re: A message to Jo Prusa

Daniel,
About the filament database, a thumbs up- thumbs down system (much like a poll or a voting system), would narrow fast the working range of settings to get perfect tips

Re: A message to Jo Prusa

i'm sure something like that will come out slowly.
i can say Hatchbox PLA seems to work fine, yellow was a slight issue.
INLAND PLA is being use
ESun.

these are ones i heard about.