My board shear did not come with an easily adjustable back gauge. For a while I used a carpenter’s square and press magnets, but decided to upgrade to an adjustable fence. Fortunately, the frame had just enough clearance for a 3/16” rail that the gauge slides along and locks to. For added stability the end of the gauge has a MagJig switchable magnet. One big advantage of this design is that the gauge can go to very close to the end of the table (since the photo was taken I switched to a longer rail so that the middle of the gauge can be at the very end of the table). A small channel was also cut from the blade to fit over the adhesive rule.
