Factorio Forums

If you bring 2 belts together to 1 and for example a mining drill is putting items on this specific belt, you can see a weird overlapping of some items.
The following picture should make this clear: This can cause further problems with items stuck in corners or as you can see in the picture blocking half of the belt.
Its quite easy to reproduce, nevertheless i'll upload a savegame.
https://drive.google.com/file/d/0ByUuLx ... sp=sharing

That's known and the case since... too many versions. Don't output items straight facing away on a belt. This will hopefully be solved as soon as the whole belt mechanic is optimized.

This is sometimes considered a feature.