Stein has finished my avionics harness and is shipping my radios and harness to me. Several months ago I decided to use T-channel as the method to secure the radio racks. I have already cut, drilled and installed the channels on the instrument panel. I needed specific sized washers the fit inside the channel which weren't made by anyone I could find. So I made my own out of 6061-T6 aluminum.
The way this works is the nuts slide into to T-channel. They are slightly smaller than the T-channel so they will slide up and down, but they won't twist. This allows me to attach a radio tray to the nuts with size 6 screws and slide it up or down to the correct position, then tighten the screws into the nuts. Should I need to replace a radio I will be able to reposition the nuts to match the new tray.
Also this week I finalized how I will attach the carb heat lever to the carb heat valve inside the air box. This took more time than I should have spent but there were several different options, each requiring unique hurdles to overcome. That should get completed tomorrow. After finishing that I will be able to rivet the airbox together and install it.
Channel attached to the back of the instrument panel