sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
i get more print errors on MK4 because nozzle cant clean iteself properly and causes bad mesh leveling and print faliure at the end.
much more than you can imagine, MK3 was more stable on this regard.
nozzle cleaning is a big issue on MK4. need a proper update with hardware or a seperate cleaner as soon as possible.
RE: sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
Some people who have had issues with Nozzle cleaning have found that the screws that hold the nozzle in place, on the nextruder, have loosened enough for the nozzle to move slightly 
Make sure the screws indicated with Arrows, above, are tight,
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE:
I always thought that an inductive sensor was more accurate than a strain gauge. Prusa should leave the ability to operate the Superpinda sensor in the MK4. This is stopping me from upgrading to 3.9
RE: sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
I always thought that an inductive sensor was more accurate than a strain gauge. Prusa should leave the ability to operate the Superpinda sensor in the MK4. This is stopping me from upgrading to 3.9
That isn't fully true. Inductive sensors do a good job at keeping a good set distance above the metal in the build plate. (This assumes its temp. compensated, which earlier Prusa sensors were not.) Problem is, people don't typically print on a metal build plate, they print on PEI, blue tape, or PEX or a bunch of others. But an inductive sensor can't see plastics, only the metal base. Use a thicker or thiner PEI sheet and you must adjust the Z-height.
A strain gauge measures the surface of the bed, and it doesn't matter if its metal or plastic or blue tape. Of course, this is really not any new technology. The Creality CR-6 did this in early 2021. But the nozzle must be clean to get an accurate reading. So change the PEI or PEX thickness, and it should adjust.
RE: sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
That's odd... going from MK3S to MK4 was the best thing i did in my life.. ok, i'm exaggerating, but it was definitely the best decision in 3D print world. No more Z-height adjustment when changing plate (and i do that pretty often), way faster printing, way better handling with color touch screen...
I guess you have some problems that can/must be solved. MK4 is a great printer and it works, so trust me, it's not a mistake. If printer is new turn to prusa support, they'll help you.
RE: sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
i get more print errors on MK4 because nozzle cant clean iteself properly and causes bad mesh leveling and print faliure at the end.
much more than you can imagine, MK3 was more stable on this regard.
nozzle cleaning is a big issue on MK4. need a proper update with hardware or a separate cleaner as soon as possible.
You are very correct. With the MK3, you can just start the print and leave. But with the MK4, you need to make sure that oozing does not break the mesh bed leveling.
The hardware fix for this, is to get the MMU3. It retracts the filament after a print. So there is no oozing during mesh bed leveling.
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You are very correct. With the MK3, you can just start the print and leave…
Well, it’s not that simple… with MK3 you also couldn’t “just leave” since you never knew if first layer will stick: if you changed bed and forgot to change that in software you’ve had two options: either first layer didn’t stick or first layer bumped to table. That’s solved with MK4.
in any way you can’t ‘just leave’… anything can go wrong, so it’s important to be there until first layer starts succesfully.
RE: sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
I was concerned that oozing might cause issues with the bed leveling. That was before I sold my MK3S and was thinking about buying the MK4. My MK3S definitely oozed. My MK4 doesn't. That is because the temperature is lowered to 175 degrees during the leveling procedure.
As a precaution, after I load the filament, I always cool down the nozzle, even if I will start a print in a few minutes. I also peek at the tip of the nozzle, and if I see anything I give it a quick wipe with a balled up kimwipe. Most of the time I don't need to do that.
Quite often I start the print remotely and don't have any issues. I only use PETG and PLA with the satin sheet. That being said, two times I sliced for PLA and printed with PETG. That was ugly.
RE: sold my MK3s+ after 5 years of usage and bought MK4, looks like a mistake
Man, I gotta invest on one of these 3d Printing. This stuff is amazing what you people create.