snap to grid with even number on ysize

I found a strange thing while modeling and hope anybody can help me.
I turned on Snap to grid and set the ankle (RZ) to 90. If the Object (Conveyor) SY is an even number, the position is not really snaped to the shown network.
As seen in the attached model.
This wouldn´t be a big problem, with turning off the snap to grid.
But I want to set location by setloc(); and this way its getting little more difficult to find out where to set. Even if I try to set the position dependent on the position of other objects. Maybe as shown in a Container.
On Reset both Conveyors should be set to Location (0,0,0) of there Containers.
Can anybody help me?

Sebastian,

if you look into the conveyor's tree, you find a node /spatial/centroid.
If this is set to "1" as it is for the conveyor by default, z rotation is performed around the center point of the yellow bounding box.
If you want the rotation to be done around the upper left corner, you will need to set the node centroid to "0".

Best wishes

Ralf
aka Ralle
Flexsim