I discovered that I needed to trim several 4×4 posts on an outdoor project. I was unwilling to attempt the cut with a portable circular saw, so I devised this self-clamping jig to guide a handsaw for the job. The jig consists of two 3/4"-thick wooden bars connected by a pair of carriage bolts and lock knobs. I sized the bars a few inches longer than the width of the pieces to be cut, and ensured alignment of the bolt holes by stack-drilling them on the drill press. A ledger strip on the top of each bar provides a wider bearing surface for the handsaw. I used polyethylene for the strips for durability and minimal friction, but dense hardwood would work. The jig is so accurate and easy to set up that I now use it on other parts that are too big or awkward to cut on a stationary machine.