in my mind I've convinced myself that anchors are much like constraints in Inventor. I'm expecting that I should somehow be able to use anchors to constrain a duct system to a furnace for instance. I've read the text and it seems as though the description would agree with my understanding. I've used the command but felt completely in the dark while trying to follow through with what it was asking me to do. I've attempted a few things... but I'm embarrassed to admit.. I just don't get it and my duct still isn't constrained to my furnace. so now that I've revealed how dumb I am... could somebody please shed a little light on what anchors are, and how they work... thanks -- Bil (with one L {and no clue})