Mirroring multiple objects does not give expected result...

Hi. I made a bird wing with feathers for the left wing of my character, and now I need to mirror this group to add the feathers for the right wing. I’ve tried scaling the whole group -1 along the x axis (pivot “median point”, 3D cursor in the middle of the scene, etc), but this is not what I expected. This is what they look like directly after cloning:

And this is what they look like after scaling the whole group -1 on the x axis:

I think it might have something to do with the rotation, but I can’t simply apply the rotation because the feathers are linked objects. I’ve tried “make single user”, clearing parents, applying scale/rotation and then mirroring it, but some of the feathers still look slightly offset. I would really like a solution because I don’t want to have to reposition them manually, especially because I think I’m going to clone the wing a couple of times.

Thanks in advance!

If the wing is a linked object, maybe try creating the ‘pair’ of wings in the original blend file, and link in that as a group?
The only thing you should be modifying on linked objects is global position, orientation, and scale. Trying to edit linked objects like they’re native objects (negative scaling, mirroring, etc) doesn’t work so well, because you create conflicts between your linked instance and the original data. Or something like that.

Make sure rotation and scale is applied (ctrl+A).

Alternatively you can create an empty in the middle of your character and then use it as the center point for the mirror modifier (there should be a drop down menu in the menu modifier where you can select it)

I tried it again and it worked, however, now I can’t link the feathers back to the original model because the rotation is applied and when I do, they are all the same size and rotation…

I found a solution: I parented the feathers to a cube at 0/0/0, then mirrored the cube. Worked like a charm.