Put the frames together and level everything, and add the camera rail.
Add leveling feet to all remaining legs on the platforms
Cut a 12" piece of 2" t-slot aluminum and insert 2 t-slot nuts on the top track and 4 on the lower track (see photo).
Attach the 8-hole plates to the legs of the reel platforms and the gate platform as shown.
Attach the 2" t-slot cross bar to the 8-hold plates.
Cut a 12" piece of 2" t-slot and slide 1 t-nut slot into each track, facing up. Attach the 4-hold 90-degree brace.
Attach the camera track arm (the 2" x 12" t-slot) to the 2" cross bar.
Using a level, adjust the leveling feet so that everything is level.