The nozzle goes down and melts the print  

The nozzle goes down and melts the print

Hello. At the outset, I will say that I bought a Prusa Mini + because I was fed up with Chinese cheap printers. I wanted to finally focus on printing and the joy it brings ....

I have it for one week and all I have is willingness to give it back to Mr. Prusa !

I purchased the printer partially assembled. So it took a few minutes to plug it in. Minor problems with skewed XZ axis. I wrote for help to the support. And after a few minutes the problem was solved. I have printed a dozen or so simple models. They turned out to be amazing. 

The first larger print - it was a small Iron Man mask for a memory card box. 

Filament PLA, Prusa Slicer. Standard settings for PLA. Layer height 0.07. Print time 6,5h While printing, I saw something like this!

As you can see in the photos, part of the print is melted. The top layer is partially OK. however, in one corner everything is melted below the level of the top layer. When I entered the room, the printer nozzle was at max on the right and the screen displayed "leveling error". I set the model in a different orientation and repeated the printout. The effect was similar though not at the same height.

Write for help again. I got a link to tutorials to check the axis level and a request for a test print. Doggy from the memory card that came with the printer.

After my second failure, I decided to replace the PTFE tube on the Hotend. Everything according to the guide. Then I re-leveled and calibrated the printer.

All axes are mounted correctly. They're at the right angle. The screws are tightened. The trapezoidal screw has no damage. The whole thing moves smoothly on EVERY axis without any jamming. I have reset the printer software to the factory settings. I tested and calibrated again. All tests are OK. First layer calibration correct. The doggie printout came out almost perfectly. I made a few more simple prints. Then I tried something more complicated. I decided to print the Witcher medallion. Everything is printed on PLA filament all the time. Only the Iron Man mask on a filament from another manufacturer. The rest on the Prusament PLA. The medallion came out very well.

The next print is two medallions on the table. During printing, when I entered the room, the nozzle moved outside the print area and on the table such a view

As you can see in the photos, the nozzle suddenly dropped below the printing level. It has melted part of the printout and the whole thing can be thrown away. I re-checked each axis, bolts, and test and calibration. I removed the Prusa Slicer. I downloaded it from the Prusa website and reinstalled it. I printed a tube as a test. PLA Prusament, settings unchanged. Layer height 0.05

Beautiful printout! No problem. I also added the medallion to Slicer again, this time one. After the printout is finished, such a view

Pay attention to the left eye. The entire printout ended without any problem. Most likely at the end the nozzle will not go back into position. She went down and melted some of the print and shifted the PEI plate.

I have no idea what the problem could be. But as you can see, it IS NOT possible to print more demanding prints!

I hope that some of you had a similar problem ... And you will help something 😭