Who says you need a table saw. This is a nice build where the author basically makes a base with some caster wheels and rolls a table across the part to cut with the circular saw. This looks much easier to use and move around that a full size table saw, and most of the materials the author used where leftovers.
http://www.instructables.com/id/How-to-convert-a-hand-held-circular-saw-into-a-cro/
http://thegreenlever.blogspot.fr/2015/01/crosscut-saw-table-designed-and-made.html#.VL_dP83d-V5