Building a homemade table saw rip fence from steel typically requires a welder, cutting torch, angle-iron, square tubing and more. Using these materials may allow you to create a very effective T-style fence, there is a simpler and less costly way to build a fence from some plywood and a pipe clamp assembly. While this fence can be a little more difficult to position, once it is clamped into place, it is accurate and won't move, which are the two most important features of a table saw rip fence.
A homemade table saw fence can be more versatile than the fence that came with your table saw, particularly if you have extension wings that extend beyond the width of your saw. Clamping your fence onto the wings allows you to cut wider stock than would be possible with the stock fence.
A homemade table saw fence doesn't have to be built out of welded steel tubing and L-brackets. A simple version can be built from evenly-cut strips of plywood and held in place with a large pipe clamp. The jaws on the pipe clamp can attach to the saw table or to an out-feed table, as long as it is parallel to the blade when the clamp is tightened into place.
Measure the length of your table saw from the front of the table to the back. You'll need a section of 3/4-inch threaded pipe no less than six inches longer than this measurement.
To build the body of the fence, you'll need two strips of 3/4-inch thick plywood measuring four inches wide by the length of the table saw you measured above. You'll also need two strips of plywood at 2-1/2 inches wide, by the same length. Finally, you'll need two small squares of 3/4-inch thick plywood measuring 2-1/2 inches square. Drill a one-inch diameter hole precisely in the centre of each of these two squares.
Configure the four long strips of plywood into a long square tube. The 2-1/2 inch wide strips should fit in-between the edges of the four-inch strips to create a four-inch wide square tube. Fasten the plywood together using some 1-1/2 inch deck screws. Then, insert one of the squares into each end of the tube, and fasten these in place (flush with the end of the tube) with deck screws.
Place the crank end of a 3/4-inch pipe clamp kit onto one threaded end of the pipe. Then, insert the open end of the pipe into one end of the square tube, and out the back end. Place the back half of the pipe clamp kit onto the open end of the pipe.
To use your homemade table saw rip fence, place the square tube fence onto the table to the right of the saw blade, with the crank end at the front of the table. Rotate the clamp so that the jaw is aligned with the front of the saw table. Reach around back, and rotate the rear jaw so that is also aligned with the saw table, and slide it forward to engage the table. Slide the fence left or right to put it into the desired position, and tighten the crank on the front of the clamp assembly to lock the fence in place.
Because this homemade table saw fence is constructed from plywood and a pipe clamp, it is more difficult to align with the saw blade than a T-style fence. A quick way to be sure that the fence is parallel to the blade is to measure the distance from the fence to one of the mitre slots, at both the front and back of the saw. If the fence and mitre slot are parallel, the fence is parallel to the blade.