What causes this testpattern error?  

Trusted Member


since I am using another hotend this probably isn´t really related to prusa but maybe someone knows what causes this.

I am trying to isolate problems and it is a bit difficult when you don´t know where to start.

So the testpattern is fine as long as there is no direction change. What could I do to prevent this?

Posted : 28/07/2020 12:18 pm
Famed Member

Generally either a bed that isnt fully clean or a Z offset that is slightly too low.  Looking at the other lines my bet is on a slightly too low Z.  

The method outlined in this thread https://forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/   is far superior to the built in method for adjusting your relative Z offset.

Posted : 28/07/2020 12:32 pm
Trusted Member

Thanks neophyl, I´ll have a look at the other method, tried to locate it yesterday in the forum but couldn´t find it. Thank you for the link!

Posted : 28/07/2020 12:35 pm
New Member


Double check that your filament type setting and temperature match what you are printing with. I had strange results similar to this when I loaded some new PETG filament that I actually thought was PLA and thus was printing it too cool.

Posted : 28/07/2020 5:01 pm
Trusted Member

Nah the filament type was right but I played a bit with the temperature settings now, did the first layer calibration like 20 times and come to the conclusion that my filament needs to be dried as well. Currently in the oven, while printing freshly opened ABS, which just prints fine.

Posted : 28/07/2020 6:45 pm
Peter M
Prominent Member

In your picture it looks to be, to low(first layer calibration), and not sticking enough, bed needs to be very clean.

The 2 things above are very important for your prints, and also so you do not get the big ball of filament sticking to your extruder.

Clean bed with dish soap, then it sticks very good again.

First layer is important, also for sticking.

If still not good, you could also try more heat on extruder, slower first layer, more heat on bed.

Posted : 01/08/2020 10:22 am

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