Hi, I don´t know if the following is even relevant, but since it is a curved surface, to make a hole in it, you´ll have to cut through the geometry - see here - http://forums.sketchucation.com/viewtopic.php?f=18&t=11222 Or you can use this http://www.smustard.com/script/BoolTools Some interesting solutions here http://forums.sketchucation.com/viewtopic.php?f=323&t=28931&hilit=lattice

@tig said: Try group.entities.add_instance(other_group.entities.parent, other_group.transformation*group.transformation) other_group.entities.parent.instances[1].material=other_group.material other_group.entities.parent.instances[1].layer=other_group.layer### you can also copy over other attributes of 'other_group' if appropriate other_group.erase! 'other_group' is 'cloned' into 'group.entities' and the original erased - here we also copy its material and layer... Thanks for this. Was useful. Of course, assigning names (variables) to each instance, makes copying layer straightforward; group2.layer = group1.layer