I like my table saw. It has a much larger top than a contractor saw, but was more affordable than a full cabinet saw. I will likely upgrade some day, but am fulfilled for now. That doesn’t mean I can’t make it better. A folding extension would really help with large and long pieces that want to fall off the back side of the cut.
I started without a few ideas of how best to build an extension, but not a fully fleshed out plan. That can lead to trouble, but it worked out pretty well in my case. I bolted on a wide board to the back to act as a good starting point. I used some of the laminate covered plywood from my table saw fence to build two fins facing outward. The idea is to use these as a hinge surfacesd. I made sure the slick plastic was facing out on all sides.
Ideally the extension meets seamlessly with the end of your table. In my case the the fence has bits that hang down below the surface and would interfere with an extension. I dropped the extension surface slightly and had to live with a gap. Small parts could fall through, but big and long cuts will droop enough to engage the new surface.
From there I used more of the plywood to straddle the fins I had made earlier and drilled through everything with a 1/4″ bolt to act as a hinge. Initially the outside corner of the fixed fins wouldn’t let the extension down all the way, but a small bit of rounding freed them.
The extension rotates freely with the interfaces being plastic on plastic. I added a cleat underneath and another to the table saw. No fancy mechanism, just a simple bit of cut 2×4. Magnets in the brace keep it held against the tablesaw when not in use. Everything feels pretty sturdy when in place.
Other than the compromises with respect to meeting the table saw surface it turned out well. It doesn’t add too much size to the saw when folded up, and provides a decent extension. I might want it bigger in the future, but I should be able to unscrew the top surface while leaving the hinge pieces in place. I could install one much wider and longer not have it take up any more space. I will have to try this out for a few weeks and decide. There is enough plywood left over to make the extension either a lot wider, or longer.