Prusa MK3S+ Prints Failing Every Time
I have had my printer about a month, and it worked flawlessly for the first 3 weeks or so, ran about 2-3 kg of filament through it. But from one day around week 3 onward its not been able to make a single print correctly.
In troubleshooting it (running various calibration settings) I found that it somehow "lost" its first layer calibration setting, and had the value of -.0000 and in recalibrating it I found it needs to be manually set to -.1100 to pass a first layer calibration test (zig-zag pattern with a solid flat single layer rectangle/square at the end of the pattern).
However, this did not fix my problem....
Prints will lay a first layer successfully. It adheres to the build sheet perfectly and strongly. At some point, say 1/3 to 2/3 of the way into the print, a horizontal crack will appear in the print as if one z-axis layer is refusing to bond to the layer below it. The print will then either come apart and begin a spaghetti mess, or it will manage to stay together but will have a big crack/defect. Usually the result is nothing but a mess of spaghetti.
Running the Official Prusa benchie gcode for the Prusa MK3S+ this is what happens (see attached photo).
I am at a loss as to what is wrong. Someone on reddit suggested that the heater block cables (or the temperature sensor) are intermittantly not working and that his friend had the same thing happen with their MK3 kit.
However, mine is a factory assembled unit.
1- How does a first layer calibration get "lost" and become .0000?
2- Why is the print coming apart? Its not a slicer setting if it happens even with the benchie gcode direct from Prusa.
Not sure if related: The problems began after trying to use a spool of "PLA extrafill electric grey." The printer did NOT like that filament (bought directly from Prusa). Stringy mess every time. Switching to other PLA filaments (from Prusa or Amazon) immediately improves printing but I am now having this same failure in every print.
Are the layers generally adhering strongly?
Is the part fragile at points where the cracks are not apparent? If so, a few degrees hotter might help.
Have you cleared out the remains of the dodgy filament with a cold pull?
https://help.prusa3d.com/article/cold-pull-mk3s-mk2-5s_2075
BTW: the PLA extrafill electric grey might be damp; try drying it. Filamentum's products are generally good quality and if it remains badly behaved after drying they would usually like to be told, send them the batch number with your comments/pictures.
Is your mains electricity supply generally reliable? No noisy, flickery brownouts?
suggested that the heater block cables (or the temperature sensor) are intermittantly not working
If you are using the latest firmware this would trigger a thermal model protection error.
1- How does a first layer calibration get "lost" and become .0000?
The only repeatable routes are an incomplete recalibation and a factory reset:
https://help.prusa3d.com/article/factory-reset-mk2s-mk2-5s-mk3s_2216
- I did know someone who repeatedly factory reset his machine - a rather nasty Prusa clone with an acrylic frame, because the reset was one of the few operations listed on the two sided 'manual' included with his kit. He blames and rubbishes Prusa because his 'Original Prusa'; it must be, it says so on the front panel, isn't worth the £120.00 it cost him... and I think he blames me because I told him Prusas were good value.
mine is a factory assembled unit.
It's actually commoner to break a factory assembled unit as kit builders generaly have a better idea of the limits.
But this doesn't sound like a seriously damaged machine.
Cheerio,