I wonder if someone here might know why this is happening. I have a file in sketchup 8 pro. It contains several solid parts i'm trying to combine into a single solid mesh through the use of the union tool. The parts are organic in form and so their triangle count is fairly high but not beyond that of sketchup. Whenever i use the union function on these models the results randomly float between one of the two selected parts just disappearing or them both combining but the union doesn't remove any interior geometry almost like it had run an intersect with model command instead. the models are meant to be 25mm miniatures but they have been scaled up by a factor of almost a million. I've tried the union opeartion with a lot of varient parts and sometimes it happens sometimes it doesn't its quite frustrating. I've even tried reinstalling sketchup and removing all my plugns but it continues to have the error. I've attached two links to two sketchup files. the first is a copy of the figure with the solid parts seperate. the second is an example of what I get when i union the parts. https://docs.google.com/open?id=0B3f58gvQLC00Y2ZiZjRiMzAtYTJ lNC00YjZjLWI1YmYtMGZkZmRlNTZiZmE2 https://docs.google.com/open?id=0B3f58gvQLC00YzgxY2U1M2EtM2R kOC00MWRmLThhMTQtNWNkMTA2MjYyM2Rk If anyone can shed some light on what's happening I'd be greatful.