"Yeah, it's strange that they don't make a circular saw that just snaps into a table so you can use it as a table saw."
And thus the seed was planted. I remember at the time I brushed it off, but a few days later a friend and I decided to sketch the plans out for one and try to make one with three criteria:
1) Make it cheap.
2) Design it so that all you need to build it is a drill and a circular saw.
3) Design it so that you can easily remove the circular saw when needed.
The video below is a time-lapse of us building our Circular/Table Saw over the course of ~4.5 hours. We were planning as we built, so I am confident that this could easily be replicated in 2-3 hours.
Step 1: Materials
Circular Saw (More on this ahead)
1/4" 20 Machine Screws
1/4" 20 Wingnuts
1/4" Lock Washers
2" Wood Screws
3" Wood Screws
3 2x4's (Pine)
2 1/2x1's (Pine)
2' by 4' sheet of particle board
Everyone has their own method of selecting lumber, we like to look down the length of the wood and search for warping. Sometimes I like to lay the wood on the ground and see if it rocks or falls over, but this method requires the floor is even. Finally, make sure there aren't too many knots.
All in all, this project should cost less than $70. That's including the cost of the circular saw and all components (but assumes you own a drill and the necessary drill bits).