Hi all,

I am try to use the hair (particle) system to cover a mesh with duplicates of a group of objects.

However, I cannot get the duplicates to align as expected.
I want all the duplicates to point to more or less the same direction as the left side of the image, but if I rotate my main object 90 degrees (Z-Axis), then all the duplicates will change their orientation as on the right side of the image (kind of circular).

My question is that, how can I control the orientation of duplicates as expected no matter how I orient my object?

a rendered image to show the duplicates' orientation
https://plus.google.com/photos/115486446704999580476/albums/5793914533346767649?authkey=CKzL0pPg35SGOw

Blender file
https://www.box.com/s/n0j6rpetysjmuggehl0k