Here's another hand tool jig. This one is more specific than the dovetail paring jig I showed in the last entry, because it's built to help with one particular step in one particular project. I use it to turn tapered square chair leg blanks into tapered octagons when I make the ladderback chair developed by J. Alexander and Drew Langsner. The dovetail jig can be used for joints of different thicknesses and widths, and I can even picture myself using it to fair up tenon shoulders. But this leg-tapering jig is so specific that I doubt it will ever be used for anything but this project.
First I'll show about making and using the jig, and then I'll explain my thinking a little bit.