This drawing/sketch shows how I cic mine. to help with my written explanation.
Pics of the board didnt show it well enough.
Here is the parts list
1- spacers to hold angle in level alignment
2- hex nuts 1/4 20
3- aluminum angle
4- threaded rod 1/4 20
5-thumb nuts 1/4 20
6- aluminum angl
7-aluminum flat stock
I only showed the side view of the parts that had alignment needs.