DupliGroups - flipping them and implications on coordinates

Hello Blender Artists,

I have created a mechanism with pistons etc that all work nicely together. I have put all these in a group.

I then use an empty to make an instance of the group by doing a dupligroup on that empty, and i need this dupligroup instance to be a mirror-image of the original group, so I give is a -1 scale transform along the Y.

The trouble is, when I move the original group positive-Y, the apparent geometry of the dupligroup goes negative-Y. Even if I give the empty that is the site of the dupligroup a constraint to follow the original group, the empty will follow but the apparent geometry based on that empty will still go in the wrong direction!

SO is there a way to fix this in the set-up I have, or is there another way to create instances of a grouping of mechanical objects and flipping them then having the 2 mirrored version move together as one?


Instance is a copy. And, I don’t think you can edit it at all.