Proof Prusa knew the Mini was flawed  

RE: Proof Prusa knew the Mini was flawed

I think flawed is a faulty word.  It is a limitation, but it works for many users.  To use Prusa's words, the printer works for 99% of users.  The 1% just tends to be more vocal.  

Thanks for sharing.  I now know better understand the Mini's limitations and will make sure my printer shop has the right environment.  

RE: Proof Prusa knew the Mini was flawed

@charles-h13

I think you are probably right that "flawed" is to strong a word. It's a good little printer IMLO, but could be a great printer.

It's just frustrating, that first print of the morning take a couple of attempts to get the Z-level right.

RE: Proof Prusa knew the Mini was flawed

Maybe the design is "sub-optimal". Personally once I'd adjusted the hot end height and added a warm up delay before the auto levelling, I've not had any problems, but there are enough people having issues to make the case that something needs to be done.

It's been mentioned elsewhere on the forum that Prusa are working on a solution, so let's see what they come up with, hopefully we won't have to wait too long.

RE: Proof Prusa knew the Mini was flawed

@gordon-w

"sub-optimal" I like that way of putting it.

Is that a Noun meaning "Designed by accountants, not engineers" 😆 

RE: Proof Prusa knew the Mini was flawed

😀 One of the many meanings! To be honest any design or testing that doesn't deliver the anticipated results even if accountants weren't involved! At work we often have to put a positive spin on things, so problems become "solution start points" 🤔 

RE: Proof Prusa knew the Mini was flawed

My understanding is that much of the MINDA problem is an environmental issue when printing in less controlled environments.  I may have to add a heater to my print farm building that I am constructing.  

RE: Proof Prusa knew the Mini was flawed

Mine was delivered on Jun (order January). and I do no see any fault (print PETG, rare PLA, no enclosure ) since I started  printing. With leveling I have non-changed steady high of 1,3mm/1,5mm sensor <->bed based on filament type since first print. Only issue I see is with some more plastic PLA on extruding, which is known issue.    Could it affect only versions that were before the big postpone in March/April sent ...  or could it affect only printers that have very small space between probe and bed ?

RE: Proof Prusa knew the Mini was flawed

@charles-h13

I strongly disagree, many users aren't savvy enough and/or haven't experienced anything better than cheap printers that constantly need adjusting. One of my friends purchased a mini and said he had no issues. When I mentioned the Z height issue, he mentioned he just prints with a raft and/or adjusts the Z height at the start of every print....to him this is normal since he previously had a beat-up makerbot. He did not report any issues because this to him was expected. 

I print in a controlled environment of 70 ±3 degrees Fahrenheit, 50-68% humidity, and the printer is within a 3/5 enclosure (top and 2 sides). I experience the issue even with temperature dwelling / preheating before prints, albeit it is limited. I still cannot print remotely without crashes/failures (my printer varies ± 0.03mm even with all my improvements, before it would vary up to ± 0.2mm).

So this is likely affecting a large number of users, but many don't report it. Those of us with experience in printers that work well (Prusa i3 Mk3s - friends and work) expect the printer to work at least as well as the other printers do. This is the first printer I've owned where I cannot let even a single print start without me in the room, and I've owned the Anycubic i3 Mega, Anycubic Kossel Linear, Multiple Ender 3 Pro's, and one reprap. Once you set up a reliable printer, it just works until it starts to drift out of level and even then it takes a few prints before I'll start experiencing failures.

RE: Proof Prusa knew the Mini was flawed

@drkmstr

It is funny that a lot of folks don't have your problems.  Either I am a lot savvier than you (which I doubt), or it is something else that not all printers have in common.  There are only four things that could be different between my printer and yours, the user, the filament, the environment, or a difference in parts used to make it.  It certainly is not that you give the printer more to print.  I have printed PLA to PC Blend and even flexibles.  

I can tell you only one thing, there is a heck of lot more folks with reliable Minis than not.   I just can't figure out why they are having problems. There no reason to get mad at a suggestions I made.  It was suggested in several other threads by others.  

Either way, I hope you get it printing.  

RE: Proof Prusa knew the Mini was flawed

@drkmstr

Got A8->AM8 ... and now Mini and I am almost sure I do not have the issue. Can you try to add height to probe from bed. Like above 1,3mm (pinda/noozle<->bed), so that temperature would less affect the sensor. Also I got original FW 4.0.5 , not upgraded yet.

RE: Proof Prusa knew the Mini was flawed

@kiwo @charles-h13

The disparity between our experiences is also a problem. This inconsistency means there must be a problem with a few percent of machines and Prusa cannot determine the cause. 

RE: Proof Prusa knew the Mini was flawed

Prusa admits it is a hardware problem -> https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/309#issuecomment-703460297

RE: Proof Prusa knew the Mini was flawed

I am always lucky with things like this, first Prusa I buy is defect by design 🤭

RE: Proof Prusa knew the Mini was flawed

I am starting to have a few issues.  Shift live Z.  I will have to retune it and post the results.  

RE: Proof Prusa knew the Mini was flawed

@charles-h13

Just in case, make sure your MINDA is holding tight, and also check those 3 grub screws. When I had issues of Z gradually decreasing, it was because as it turned out one screw was free and another was so-so, heatbreak was slipping down in heatsink.

RE: Proof Prusa knew the Mini was flawed

@crawlerin @charles-h13

Check the height of the extruder, the grub-screws holding the heat brake tube in the heatsink can come loose. There's a lot of force on them, especially when things get clogged. It's a simple operation, Prusa Support likely has a document outlining it by now.

Looking forward to your results, I hope you're issues are only temporary.

RE: Proof Prusa knew the Mini was flawed

I don't know about you guys but I have become quite a master at setting the Z height on the fly at the start of every print..

RE: Proof Prusa knew the Mini was flawed

@hannes-b3

My current procedure appears to be:

1. Set it to the known good value
2. Print a Layer 1 test that fails.
3. Adjust Layer 1, still fails.
4. Retry the the known good value, bingo

RE: Proof Prusa knew the Mini was flawed

Posted by: @hannes-b3

I don't know about you guys but I have become quite a master at setting the Z height on the fly at the start of every print..

Hey that's a valuable skill to have! 😀 I watch first layer like a hawk too ... though if it's 45 minutes+ I may give up at some point.