That's the site I got my idea from. The only change I made was that I didn't like the slot you had to cut in the center of the rails to mount the controls.
I didn't like the fact that you had to pull the centetr control any time you needed to swap ANY control. and what if you wanted to mount a really big control (steering wheel, fligh yoke, etc.?
So, I left the rails intact, and drilled a whole near each corner of each control pod. I attached the clamps with a double nutted screw (one before and one after the clamp), through each hole.
So I drop the control pod in place and use a screwdriver to turn the clamp s under the rail. Just reverse to remove.