I wanted an adjustable end stop with a low-enough profile to reach under the guide rail for narrow crosscuts. This one is 16 mm high, so it will slip under the rail when cutting 18 mm material. 

The slider moves freely (see note below), then a quarter turn of the pin locks it in place. 

A pair of these will work as a guide for narrow (or wide) rips as well.

I've provided a base to elevate the stop, for those using sacrificial strips under the workpiece, along with locating dogs for use with the elevated base or directly on the MFT table.

Notes on printing…

• I used PLA-plus/pro with four wall loops, four bottom and top layers, and 40% fill. The 40% fill in particular is probably more than what's needed.
• I used scarf joints. If they're not available in your slicer or not set up to use them, you may need to lightly sand the seams on the dogs and/or dog holes.

Notes on assembly…

• Drip the locking pin into the hole in the base. There's an ejection hole on the bottom of the base in case the pin ever needs to be replaced.
• Insert the spline from above, then insert the slider.

Note: When first assembled, the slider will be pretty tight. In my experience (with good quality PLA+) it will slide very nicely after being assembled for a couple of days. You can accelerate the process by pre-bending the spline.