Calibration object is non-manifold

[nophead]

The two arches meet a knife edge.

[josefprusa]

I'm not sure I got it, there is tiny little hole between arches?

[nophead]

I think they meet tangentially, which CAD programs don't like. SF moans about dangling edges and netfabb shows it as non-manifold with the error where the arches meet.

The arches don't actually print very well on my machines because they are too thin and the big one needs to be tear dropped.