Some will say, "Why bother?" since you can now buy an inexpensive table saw for the same amount of money. True, but the adaptation shown here allows the user to remove the saw from the table at any time and rip panels or frame houses, and then return the saw to its table precisely aligned and ready to do close fitting work. You cannot enjoy that dual purpose usage with an inexpensive commercial table saw.
This Instructable differs from similar Instructables because it offers that precise mechanism for automatically and exactly aligning the saw each time it is returned to its table. Details of this are in Step 16.
If you want yet another alternative for making your circular saw an accurate woodworking machine, see my earlier Instructable Get More from Your Circular Saw. Also, after 40 years I built another conversion of an electric handsaw to a table saw. You can see it here.
Step 1: Making the miter gauge
If you choose to make your own, begin with a straight steel bar. The one shown is 1/4 x 3/4 inch and about a dozen inches long. It is what I had at the time. I would recommend a bar of 3/8 x 3/4 inch steel about 18 inches long, but 1/4 x 3/4 inch may be easier to find and works well, too. Round the edges at the ends a little with a grinder so the miter gauge moves more freely in the slots. The photos in this step and the next steps are from my previous Instructable titled Bench Saw Table for a Lathe.