Thank's a LOT Pcmoor. This a great help for me. I feel more "normal" and not so alone... I will take method 2. So if I understood well, I must rebuilt everything... No "magic" trick to eliminate old scaling of groups, and let the geometry like it appears without this "memory". Groups keep "memory" although one make them unique...! As there is no mirror copy, the only way i found is to apply a scale -1 in X or Y axe. In my project, i have a lot of components that are symmetricals and I've build all my models using this scale -1, without knowing this little "detail"... Last, When you say groups "CAN" retain, and "scaling can easily become out of sync", is it unpredictable? or is there any ley, here? Sorry to insist, but i really like to understand and avoid future problems!!! Really very grateful for your support and help. Xtian

Hi PCmoore, Thank you for explaining. Very useful Thank you once again

@unknownuser said: remember Dan Rathburn to have written a small plugin https://forums.sketchup.com/t/redraw-all-dynamic-components/77512/15

Hi! In my opinion ther are several ways to do this, and it often happens to me to use the method you're suggesting, that's to wrap the DC into a bigger DC. You know you can make the sub-objects of your DC move, don't you? I often use this method too, and helps solving lots of positioning issues I find. One last naif question: you know that the origin of the first DC is not to be taken as absolute, and you can make the origin whatever point you like/need, right? For conceptual questions, it's always nice to attach an example, so it's easier to understand what you're trying to achieve!