rethmonk

Greetings, I've been printing with the Anet A8 Reprap Prusa I3 for a couple weeks now. So far so good. until tonight. Here is a still of the model im printing as shown in Cura- -notice the large open space circled in red. But wait, during printing somehow a random wall was added- -notice how now the opening has been covered by a layer witch does not exist in cura. ( the blob in the corner is from the resulting catastrophic failure. Any help would be greatly appreciated! Thank you in advance!