here we have other good example, that cross my self yesterday, and i spent lot of time trying to align the axes, as you can see they are not snapped as it should be they are aligned by eye. and they are not well done. 
may be a way to select a face and copy the properties (angle,etc) due in this kind of pieces you have an angle and its very complicated to align the angled axe with the black birck.
![[Image: Tzk3UO3.png]](https://i.imgur.com/Tzk3UO3.png)
![[Image: OLboM3y.png]](https://i.imgur.com/OLboM3y.png)
![[Image: NuGIZLv.png]](https://i.imgur.com/NuGIZLv.png)
may be a way to select a face and copy the properties (angle,etc) due in this kind of pieces you have an angle and its very complicated to align the angled axe with the black birck.