This was made to fit on my SawStop table saw, but may work on others. The tolerance is pretty tight. I was trying to have as little lateral play as possible.
I've also included a small test print so you can check the fit before printing the whole rail.
Update 7/22/2021
I've added a version without the “T” that can be used just as a guide. I also added a version where only half of it has the “T”. This is handy for something like a sled where you want to lay it down and get it started in the track then have it lock in.
The author hasn't provided the model origin yet.