I'm searching for a tapering jig, initially to make table legs. I've looked at several videos here and on YouTube and most are based on a sled, straight edge, and hold down mechanisms. Below is a vid that was posted recently on another SMC thread. Seems that the initial setup is good for repeating cuts on 2 adjacent sides of a leg, but that to taper the sides opposite the cut sides requires resetting the blocks. Easy enough. But I don't understand how to ensure the saw blade first enters the leg at precisely the same point as on the opposing side. In other words, say for example that the initial cuts started precisely at 4" from the leg end. When moving the blocks and re-doing the setup for the opposite side of the leg, how can I ensure the blade enters the wood at precisely 4" from the end? Am I making sense? Not sure how else to ask the question. Any tricks that I'm missing?

http://www.finewoodworking.com/works...ering-jig.aspx