Log Tenons on table saw
I too, am too cheap to buy the various tenon makers, and came up with another way to cut them on the table saw. I first drill 11/16th holes in the ends of the logs as parallel as possible (I'm doing this by eye but need hints on a slick way to keep these in perfectly parallel planes), and thread in 6 inch or longer 3/8 inch bolts leaving at least 3 inches exposed. On the table saw, I clamp a simple thin board to the blade side of the fence, with a 1" deep, 3/8" dia. notch at the top, with the waxed bottom about 3" above the saw table and close to blade center, and set one of the end bolts into the notch (log is perpendicular to the blade). The other end of the log is supported by a free stand with another 3/8" notch at the top the same height as the one on the fence. I use a freestanding tool rest from my lathe with a notched insert, but have used just a board nailed to a heavy 12inch x12inch x 2 foot wood block sitting on the floor. The tenon is then cut by simply raising the blade into the wood, and turning the log against the blade rotation, while at the same time sliding the end bolts back and forth on the notches. This sounds slow and complicated, but its really not. With a sharp blade you can easily take off 3/4 inch dia. at a time. Tenon diameter, which I check now and then with calipers, is determined by blade height, and tenon length is set by the distance between the fence jig and the blade. I have found that setting the log at a slight angle, maybe a few degrees , causes the blade to progress in a spiral cut from the shoulder to the tenon end or vice versa. On lighter woods like pine, this works great-no strain, no jumping a round, and little risk as far as I can tell . Interestingly, I first tried this method by simply hammering long, sturdy pole barn nails into pilot holes in the log ends. The nails sagged or flexed a bit at their fullest extension from the notch, but the effect was to slightly taper the end of the tenon, and that's not a bad thing. This only works well, of course, with reasonably straight logs, but is pretty accommodating of bends if the notch is high enough to keep the bends from hitting the saw table. I use my standard table saw blade, but a dado might be faster. One plus or minus, depending on your tastes, is that this method produces a 90 degree shoulder, rather than a taper at the base of the tenon, but I kind of like that. I have only done this with 6" dia. logs about 5 feet long so far, but the free stand and the sturdy bolts allow you to do about any length.