I use the Stewmac fret slotting miter box to cut fret slots in guitar fingerboards. This is an effective setup and more efficient than you might think. However, when I first received the miter box, a few test cuts indicated that it was slightly out of square. There was no obvious way to adjust it and the included instructions didn't acknowledge that this could be a problem in the first place. This post describes the process I worked out to fix it.
