Wanting the convenience of a Tablesaw in a small budget and space, I built one sometime last year.
Material used is 12mm ply and the external dimensions are 15 inch x 15 inch. The machine is controlled with an onboard safety switch, with 2 sockets - one for the saw and other for the vacuum.
A lot of dust is collected in the box itself, and some of it gets sucked into the vacuum. The motor needs a separate air-inlet port, else it keeps circulating the contaminated air.
This is how the machine looks, with lamination and a new fence. A scale is now used for the guide fence. The pointer is a screw, which can be calibrated easily.

Table can be turned upside down and be used as a clamping base for small projects.

Safety Note : You should get a circular saw which has a riving knife to enhance safety of your table saw. Cumi CWS 190 E, is the only circular saw available in India, which comes with a riving knife. Using saw without a riving knife, exposes you to risk of a kickback, which can cause serious injuries.
Recommended circular saw : Bosch GKS 7000/ Bosch GKS 190