Do you ever find when trying to zoom extents in model space that your drawing just appears as a small dot!? this is because there is unwanted CAD line work in model space. A good way to get rid of the unwanted lines is to: Select the erase command or short cut type E return. Then type in 'ALL' return. Then hold down shift and 'DESELECT' the drawing work you want to keep. finally hit return. You should now find that after zoom extents is used again only your drawing will be zoomed into. Check out tmrw's daily blog for more tips and tricks for the CAD world.