There is a project I plan to build that calls for a large number of pieces of octagonal stock that are about a foot in length. I wanted to have a jig to make these pieces as reproducibly as possible, so this is what I concocted. I built this to be used with 1 5/16” square stock as the starting material. I then set the table saw fence to 2 15/16”, clamp a piece of square stock in the jig and make four cuts, flipping the stock 90 degrees each time. The pieces come out very symmetrical. There is probably a limit to how long of a piece you’d want to cut with this jig, but it could be made longer with a second clamp to handle longer pieces.