All of my prints serarate or layers do not adhere very well to each other
I have a Prusa Mini that I bought new pre-assembled. It has printed perfect models since day 1. However, now all of my prints come apart. The layers are not sticking together. For example, I printed the frog from the usb stick and just by pulling on it very slightly it just seperates in multiple different sections (or layers). I updated the firmware to the newest after the printing has been failing. I cleaned the nozzle the best I could. I haven't had any issues with flow or anything like that but just took as a precaution. So last night i reset the device to factory reset and printed a benchy. It looks good, but the layers aren't firmly stuck together. the pieces like the roof of the benchy i could pull it off with VERY LITTLE pressure. then just pushing against the hull it came apart.
I redid the tuen of the z-axis and the first layer calibration looks really good. The print looks very good but its very brittle and they separate too easily. I have the original benchy i printed when i got the machine and its as strong as it can be. It doesn't come apart with little pressure.
Also note I am using Prusament PLA as I have ONLY used Prusament filament for the life of the machine. I have never used any other brands.
At a loss for what to do to fix this.
RE: All of my prints serarate or layers do not adhere very well to each other
Did you try other filament spools?
Things to try:
- try other filament or dry the existing one, some filaments ends having problems if humid or covered with dust if unused and exposed on the spool holder for weeks
- checking nozzle for clogs - maybe there is something blocking proper extrusion, so use cold pull and a needle to clean it off. Or replace a nozzle with a new one.
- try lowering the speed, you can limit it in the slicer or during print with a tune menu
- bump temperature by 5 or 10 degrees Celsius. I believe this will need model reslicing.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: All of my prints serarate or layers do not adhere very well to each other
Thanks for the reply. I went ahead and put on a new spool of filament. And bumped the temp up 5 degrees. I will see if that fixes it. Next I will try a cold pull if this doesn’t work.
RE: All of my prints serarate or layers do not adhere very well to each other
So I raised the temp 5 degrees, put in new filament. It printed much better except the top of the benchy. The top of the roof came off, like you could just peel it off. And the pipe on top of the roof just snapped off by just touching it.
however the rest of the benchy is really strong. I can’t separate any of the other layers on the haul or anywhere else. It is just the top. Of the roof & the exhaust stack.
I uploaded pictures to show what it looks like any other suggestions on how to fix this? I will run a couple other prints to see how they print. 
RE: All of my prints serarate or layers do not adhere very well to each other
Looks like under extrusion where it's printing fast. Are you using the same print profiles you always did, or have you recently changed them.
Under extrusion has lots of potential causes, partially blocked nozzles, poor extruder door tension, printing temperature too low.
Guessing by looking at that print I'd guess maybe your using a speed profile and you need to raise the nozzle temperature by 10 degrees minimum. That infill looks really underextruded, and that makes sense because that prints at the highest speed. You can watch while it's printing and raise the temperature until it prints correctly.
The other option is to lower either the infill speed in the print settings, or lower the volumetric flow rate in the filament profile.
I have found over the years that not all filaments are created equal. Aka Hatchbox PETG has a max recommended printing speed of 100mm/sec while Polymaker PETG is only 50mm/sec.
RE: All of my prints serarate or layers do not adhere very well to each other
Bump temperature by 10C from the base value ( so extra 5C from what you did initially) and see how it goes.
If you updated PrusaSlicer then make sure to update the profiles and redo custom profiles because some things changed noticeably due to InputShaping.
Double check the PTFE tube between the extruder and the hot end if it is not worn out, also check the short PTFE tube that sits inside the heartbreak as well. If they show some irregularities in the diameters or shrinkage/expansion/burns then they need to be replaced, otherwise those will cause under/over extrusion issues.
See my GitHub and printables.com for some 3d stuff that you may like.
Have you tried a cold pull? A partial clog with, say, a fragment of overcooked filament could cause any of these symptoms.
Cheerio,