I wanted to create a coin stacking device similar to this one:
But I wanted to only 3 coins, 5c, 2c, and 1c. Unfortunately the STL came in pretty messy after importing to Blender, which made it difficult to edit the model to have only 3 stacks. So I decided to create my own. I used a box and three cylinders with the diameter of the coins + 2mm so the coins can fall loose into the stack. The cylinders where used for boolean modify the box to create the stack gaps.
Exporting the model as an obj and importing them to Cura showed it getting strange diagonal faces at the stack gaps and at the top.
After slicing however the faces were gone and the test print came out pretty decent, even on low quality settings the measurement were quite exact.
Still I would like to know why these additional faces appear and how to prevent that. I am not a blender expert, but I guess it has to do something with the topology/faces? I started creating additional edges in Blender for the isolated vertex created by the boolean modifier, but I don't know if that's actually necessary for a 3d printed model that's not going to be textured ect.