The X-31 is an amazing machine but as standard it lacks a way to set the sawblade height with any sort of precision. You raise the blade carefully, get it about right and tighten the locking handle - and find your blade has moved an eighth! This may not matter much for through cuts but for any sort of dado or joint cutting it can be very frustrating and time wasting.
Now at last there is an answer; the Precision Adjuster.
This simple addition to your machine provides for precise adjustment of your blade's height without stealing away the useful rapid motion of the original lever. A replacement lever incorporates a quick-release nut that engages a long threaded rod. The threaded rod provides both the precision adjustment and locking needed, whereas the quick-release nut allows rapid raising and lowering of the blade for instant tool changeover.
General Arangement of Precision Height Adjuster
The Precision Height Adjuster takes approximately an hour to install with modest machinery skills; you will need to drill one hole, tap two threads and assemble a small number of components.
I no longer make this device but I downloaded all the plans and parts lists etc to the Yahoo X-31 site so you can make your own