Don made the mistake of asking for more jig posts so here's the next with more to follow. The concept of the jig has different versions. For any version you want some flat stable lumber. I had an old maple table top that was part of my parents newlywed furniture 50-odd years ago. It had picked up some water damage while making it's travels from one of my dad's garages to the other over the years. I ended up with it and it has been waiting for a second life.
The jig requires two guide rails to control the width of the cut and two end rails to support the guide rails.
The general layout allows the guide rails to open and close for different widths of dados.
Over to the drill press to drill some starter holes for the adjustment slots.
On the narrow guide rail I also need a hole for the carrige bolt and a recess for the head of the bolt.
As my router table was down I used the old standby to cut the slots.
Cont'd in Part 2